C
US
2 Rinnai Tankless Water Heater Installation and Operation Manual
•
Do not store or use gasoline or other flammable vapors and liquids in the
vicinity of this or any other appliance.
•
WHAT TO DO IF YOU SMELL GAS
−
Do not try to light any appliance.
−
Do not touch any electrical switch; do not use any phone in your building.
−
Immediately call your gas supplier from a neighbor’s phone. Follow the gas
supplier’s instructions.
−
If you cannot reach your gas supplier, call the fire department.
•
Installation and service must be performed by a trained and qualified
professional, service agency or the gas supplier.
WARNING
Full-length French and Spanish versions available online at rinnai.us.
If the information in these instructions is not followed exactly, a fire or
explosion may result causing property damage, personal injury, or
death.
•
Ne pas entreposer ni utiliser d’essence ou ni d’autres vapeurs ou liquides
inflammables à proximité de cet appareil ou de tout autre appareil.
•
QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ :
−
Ne pas tenter d’allumer d’appareil.
−
Ne touchez à aucun interrupteur ; ne pas vous servir des téléphones se
trouvant dans le bâtiment.
−
Appelez immédiatement votre fournisseur de gaz depuis un voisin. Suivez
les instructions du fournisseur.
−
Si vous ne pouvez rejoindre le fournisseur, appelez le service des
incendies.
•
L’installation et l’entretien doivent être assurés par un installateur ou un
service d’entretien qualifié ou par le fournisseur de gaz.
AVERTISSEMENT
Assurez-vous de bien suivre les instructions données dans cette notice
pour réduire au minimum le risque d’incendie ou d’explosion ou pour
éviter tout dommage matériel, toute blessure ou la mort.
Rinnai Tankless Water Heater Installation and Operation Manual 3
1. Welcome ................................................................................................................................... 4
1.1 To The Installer ................................................................................................................ 4
1.2 To The Consumer ............................................................................................................ 4
1.3 Acronyms and Abbreviations ........................................................................................... 4
2. Safety ....................................................................................................................................... 5
2.1 Safety Symbols ................................................................................................................ 6
2.2 Safety Precautions .......................................................................................................... 6
3. About the Water Heater .......................................................................................................... 8
3.1 Model Numbers Explained .............................................................................................. 8
3.2 Front and Bottom View .................................................................................................... 9
3.3 Components .................................................................................................................. 10
3.4 Specifications ................................................................................................................ 11
3.5 Dimensions .................................................................................................................... 12
3.6 Accessories ................................................................................................................... 14
4. Install the Water Heater ........................................................................................................ 16
4.1 Installation Guidelines ................................................................................................... 16
4.2 What You Will Need ...................................................................................................... 17
4.3 Choose an Installation Location .................................................................................... 18
4.4 Mount the Water Heater to the Wall .............................................................................. 21
4.5 Vent the Water Heater ................................................................................................... 23
4.6 Connect the Water Supply ............................................................................................ 47
4.7 Install the Isolation Valves ............................................................................................. 48
4.8 Install the Pressure Relief Valve ................................................................................... 48
4.9 Connect the Condensate Drain ..................................................................................... 49
4.10 Connect the Gas Supply .............................................................................................. 52
4.11 Connect the Power Supply ........................................................................................... 55
4.12 Initial Settings ................................................................................................................ 56
4.13 Configure Parameter Settings ...................................................................................... 59
4.14 External Pump with Circ-Logic ...................................................................................... 62
4.15 Post-Water Heater Installation Checklist ...................................................................... 63
5. Operation ............................................................................................................................... 65
5.1 Safety Precautions ........................................................................................................ 65
5.2 Gas Operating Instructions ........................................................................................... 67
5.3 Control Panel ................................................................................................................. 68
5.4 Setting the Temperature ................................................................................................ 69
5.5 Performance Data ......................................................................................................... 70
5.6 Diagnostic Codes .......................................................................................................... 72
5.7 Configuring Recirculation (If Applicable) ....................................................................... 75
6. Maintenance .......................................................................................................................... 82
6.1 Maintenance .................................................................................................................. 82
6.2 Cleaning and Inspecting the Air Filter ........................................................................... 84
6.3 Flushing the Heat Exchanger ........................................................................................ 85
6.4 Draining the Water Heater ............................................................................................ 87
7. Appendices ............................................................................................................................ 88
7.1 Massachusetts State Gas Regulations ......................................................................... 88
7.2 Wiring Diagram .............................................................................................................. 90
7.3 Ladder Diagram ............................................................................................................. 91
7.4 Pressure Drop Curves ................................................................................................... 92
7.5 Water Flow and Pump Performance Curves ................................................................ 93
7.6 Guidelines for Additional Temperature Controllers ....................................................... 94
7.7 Bluetooth Low Energy (BLE) and App Instructions ....................................................... 95
7.8 Federal Communication Commission (FCC) Interference Statement .......................... 96
7.9 Industry Canada Statement .......................................................................................... 97
8. Warranty .................................................................................................................................. 98
4 Rinnai Tankless Water Heater Installation and Operation Manual
Thank you for purchasing a Rinnai Tankless
Water Heater. Before installing and operating
this water heater, be sure to read these
instructions completely and carefully to
familiarize yourself with the water heater’s
features and functionality.
ANSI American National Standards Institute
Btu British Thermal Unit
DHW Domestic Hot Water
GPM Gallons per minute
LPG Liquid Petroleum Gas
NG Natural Gas
PP Polypropylene
PRV Pressure Relief Valve
PSI Pounds per square inch
WC Inches of water column
•
This manual provides instructions on
operating and maintaining the water heater.
Keep this manual for future reference.
•
As when using any appliance generating
heat, there are certain safety precautions
you should follow. See section “2.2 Safety
Precautions” for detailed safety
precautions.
•
Be sure your water heater is installed by a
trained and qualified professional.
•
If installing in the state of Massachusetts,
refer to section “7.1 Massachusetts State
Gas Regulations” in this manual.
Table 1 provides a list of common acronyms
and abbreviations used in this manual:
• It is recommended that a trained and
qualified professional who has attended
a Rinnai training class complete the
installation. The warranty may be voided
due to any improper installation.
• A trained and qualified professional
should have skills such as:
− Gas sizing
− Connecting gas lines, water lines,
valves, and electricity
− Knowledge of applicable national,
state, and local codes
− Installing venting through a wall or
roof
− Training in installation of tankless
water heaters. Training on Rinnai
Tankless Water Heaters is
accessible at
rinnaipro.myabsorb.com.
• Read all instructions in this manual
before installing the water heater. The
water heater must be installed according
to the exact instructions in this manual.
• Proper installation is the responsibility of
the trained and qualified professional.
• When installation is complete, leave this
manual with the water heater (for
internal/indoor units) or give the manual
directly to the consumer.
Table 1. Acronyms and Abbreviations
Rinnai Tankless Water Heater Installation and Operation Manual 5
•
Do not store or use gasoline or
other flammable vapors and
liquids in the vicinity of this or any
other appliance.
•
WHAT TO DO IF YOU SMELL
GAS
−
Do not try to light any
appliance.
−
Do not touch any electrical
switch; do not use any phone
in your building.
−
Immediately call your gas
supplier from a neighbor’s
phone. Follow the gas
supplier’s instructions.
−
If you cannot reach your gas
supplier, call the fire
department.
•
Installation and service must be
performed by a trained and
qualified professional, service
agency or the gas supplier.
•
The warning signs in this manual
are here to prevent injury to you
and others. Please follow them
explicitly.
WARNING
If the information in these
instructions is not followed
exactly, a fire or explosion may
result causing property damage,
personal injury, or death.
• Ne pas entreposer ni utiliser
d’essence ou ni d’autres vapeurs
ou liquides inflammables à
proximité de cet appareil ou de
tout autre appareil.
• QUE FAIRE SI VOUS SENTEZ
UNE ODEUR DE GAZ :
− Ne pas tenter d’allumer
d’appareil.
− Ne touchez à aucun
interrupteur ; ne pas vous
servir des téléphones se
trouvant dans le bâtiment.
− Appelez immédiatement votre
fournisseur de gaz depuis un
voisin. Suivez les instructions
du fournisseur.
− Si vous ne pouvez rejoindre le
fournisseur, appelez le
service des incendies.
• L’installation et l’entretien doivent
être assurés par un installateur
ou un service d’entretien qualifié
ou par le fournisseur de gaz.
• Les panneaux d’avertissement de
ce manuel sont ici pour éviter de
vous blesser et d’autres
personnes. Suivezles
explicitement.
AVERTISSEMENT
Assurezvous de bien suivre les
instructions données dans cette
notice pour réduire au minimum le
risque d’incendie ou d’explosion
ou pour éviter tout dommage
matériel, toute blessure ou la mort.
6 Rinnai Tankless Water Heater Installation and Operation Manual
Indicates a potentially hazardous
situation which, if not avoided, could
result in personal injury or death.
CAUTION
WARNING
This manual contains the following important
safety symbols. Always read and obey all
safety messages.
•
Before operating, smell all around the
appliance area for gas. Be sure to smell
next to the floor because some gas is
heavier than air and will settle on the
floor.
•
Keep the area around the appliance clear
and free from combustible materials,
gasoline, and other flammable vapors and
liquids.
•
Combustible construction refers to
adjacent walls and ceiling and should not
be confused with combustible or
flammable products and materials.
Combustible and/ or flammable products
and materials should never be stored in
the vicinity of this or any gas appliance.
•
Flammable liquids such as cleaning
solvents, aerosols, paint thinners,
adhesives, gasoline and propane must be
handled and stored with extreme care.
These flammable liquids emit flammable
vapors and when exposed to an ignition
source can result in a fire hazard or
explosion. Flammable liquids should not
be used or stored in the vicinity of this or
any other gas appliance.
DANGER
Indicates an imminently hazardous
situation which, if not avoided, will result in
personal injury or death.
Indicates a potentially hazardous situation
which, if not avoided, could result in minor
or moderate injury. It may also be used to
alert against unsafe practices.
Alerts you to potential hazards that
can kill or hurt you and others.
DO NOT adjust the internal gas valve.
The design is such that adjustment is not
required. Warranty may be voided if the
internal gas valve is adjusted.
WARNING
The following precautions apply to the
installer and consumer. Read and follow all
instructions in this section.
Outdoor installations require a Rinnai-
specified outdoor vent cap. DO NOT install
the water heater outdoors without the Rinnai
-specified outdoor vent cap. Refer to the
installation instructions of the outdoor vent
cap to install this water heater outdoors.
WARNING
Rinnai Tankless Water Heater Installation and Operation Manual 7
•
DO NOT store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.
(NE PAS entreposer ni utiliser
d’essence ou ni d’autres vapeurs ou
liquides inflammables à proximité de cet
appareil ou de tout autre appareil.)
•
Always check the water temperature
before entering a shower or bath.
•
Hot water outlet pipes leaving the water
heater can be hot to touch.
•
To protect yourself from harm, before
performing maintenance:
−
Turn off the electrical power supply
by unplugging the power cord or by
turning off the electricity at the circuit
breaker. (The temperature controller
does not control the electrical power.)
−
Turn off the gas at the manual gas
control valve, usually located
immediately below the water heater.
−
Turn off the incoming water supply.
This can be done at the isolation
valve immediately below the water
heater or by turning off the water
supply to the building.
−
Use only your hand to turn the
manual gas control valve. Never use
tools. If the manual gas control valve
will not turn by hand, do not try to
repair it; call a trained and qualified
professional. Force or attempted
repair may result in a fire or
explosion.
•
DO NOT use this appliance if any part
has been under water. Immediately call
a qualified service technician to inspect
the appliance and to replace any part of
the control system and any gas control
which has been under water.
(N’utilisez pas cet appareil s’il a été
plunge dans l’eau, même partiellement.
Faites inspecter l’appareil par un licence
professionnelle et remplacez toute
partie du système de contrôle et toute
commande qui ont été plongés dans
l’eau.)
•
DO NOT use substitute materials. Use
only parts certified for the appliance.
•
Should overheating occur or the gas
supply fails to shut off, turn off the
manual gas control valve to the
appliance.
(En cas de surchauffe ou si
l’alimentation en gaz ne s’arrête pas,
fermez manuellement le robinet d’arrêt
de l’admission de gaz.)
•
Only trained and qualified
professionals are permitted to adjust
parameter settings.
•
DO NOT use an extension cord or
adapter plug with this appliance.
•
Any alteration to the appliance or its
controls can be dangerous and will
void the warranty.
•
DO NOT operate the water heater
without the front panel installed. The
front panel should only be removed for
service/maintenance or replacing
internal components.
•
BURN HAZARD. Hot exhaust and vent
may cause serious burns. Keep away
from the water heater. Keep small
children and animals away from the
water heater.
•
Proper venting is required for the safe
operation of this appliance.
•
Install the vent system per local and
national codes.
•
DO NOT obstruct the flow of
combustion and ventilation air to the
water heater.
•
Failure to properly vent this appliance
can result in death, personal injury
and/ or property damage.
•
DO NOT install this water heater
above 10,200 ft (3,109 m).
•
Rinnai recommends that every home
have a carbon monoxide (CO) alarm in
the hallway near bedrooms in each
sleeping area. Check batteries monthly
and replace them annually.
8 Rinnai Tankless Water Heater Installation and Operation Manual
Topics in this section
•
Model Numbers Explained
•
Front and Bottom View
•
Components
•
Specifications
•
Dimensions
•
Accessories
Example:
RXP199i
RX
P
199
i
Installation Type:
i: Interior (Indoor)
Maximum Gas Consumption (Btu/h):
• 199: 199,000
• 180: 180,000
• 160: 160,000
• 130: 130,000
Pump:
P: Pump (Internal Pump Included in Model)
Application Type:
RX: Residential
Rinnai Tankless Water Heater Installation and Operation Manual 9
Figure 2: Bottom View
Hot Water
Outlet
Cold Water
Inlet
Gas
Condensate
Drain
Figure 1: Front View
Vent
Connections
Controller
Supply Connections
Front View
Boom View
10 Rinnai Tankless Water Heater Installation and Operation Manual
Figure 3: Components
Controller removed for clarity
Air Inlet
Exhaust
Flue Gas Exhaust
Air Inlet Filter
Fan with Integrated
Venturi
Gas Valve
Primary
Heat Exchanger
PC Board
Burner Assembly
Ignition Unit
Pump PC Board
(RXP [with pump]
models only)
(Cover removed for
clarity)
Secondary
Heat Exchanger
Condensate Trap
Combustion
Analysis Port
Rinnai Tankless Water Heater Installation and Operation Manual 11
Table 2. Specifications
1
Activation flow rate may vary slightly depending on the temperature setting and the inlet water temperature.
2
The maximum gas supply pressure must not exceed the value specified by the manufacturer.
Rinnai products are continually being updated and improved; therefore, specifications are subject to change without prior notice.
Indoor Units without Pump Indoor Units with Pump
(Includes outdoor installaons with Rinnai-specied outdoor vent cap)
RX199i RX180i RX160i RX130i RXP199i RXP160i
Minimum Gas Consumpon Btu/h 15,000
Maximum Gas Consumpon Btu/h 199,000 180,000 160,000 130,000 199,000 160,000
Flow Rate
1
(Min-Max)
0.13-11.1 GPM
(0.5-42 L/min)
0.13-10.0 GPM
(0.5-38 L/min)
0.13-9.0 GPM
(0.5-34 L/min)
0.13-7.1 GPM
(0.5-27 L/min)
0.13-11.1 GPM
(0.5-42 L/min)
0.13-9.0 GPM
(0.5-34 L/min)
Unit Weight
55 lb (25 kg) 55 lb (25 kg) 54 lb (24 kg) 54 lb (24 kg) 58 lb (26 kg) 57 lb (26 kg)
Sound Level 49 dB 49 dB 48 dB 48 dB 49 dB 48 dB
Electrical
Data
Normal 98 W 76 W 73 W 47 W 98 W 73 W
Normal with Pump Operaon 170 W 149 W -
Standby
1.3 W 1.3 W
Freeze Protecon
142 W 174 W
Max Current 4 Amps
Fuse 10 Amps
Temperature Seng
Minimum: Normal Operaon: 98°F (37°C) (Crossover Mode: 120°F (49°C))
Maximum: Default: 120°F (49°C) With Parameter Adjustment: 140°F (60°C)
Bypass Flow Control Electronic
Gas
Supply
Pressure
2
Natural Gas 3.5 in. wc - 10.5 in. wc
Propane 8.0 in. wc - 13.5 in. wc
Type of Appliance
Super-High-Eciency (Condensing), Tankless, Temperature Controlled, Connuous Flow Gas Hot
Water System
Ignion System Direct Electronic Ignion
Electric Connecons Appliance: AC 120 Volts, 60Hz Temperature Controller: DC 12 Volts (Digital)
Water Supply Pressure Minimum: 15 PSI (Recommended 50 PSI for maximum performance) Maximum: 150 PSI
Remote Control Cable
Non-Polarized Two Core Cable (Minimum 22 AWG)
Non-polarized Two Conductor Low Voltage Cable (Minimum 22 AWG)
ENERGY STAR® Qualied Yes
Complies with South Coast Air Quality
Management District 14 ng/J or 20 ppm NOx
emission levels
Yes
12 Rinnai Tankless Water Heater Installation and Operation Manual
Measurements: in. (mm)
Figure 4: Dimensions
Vent Connection:
2 in. (51 mm)
nominal PVC/CPVC/
Polypropylene or
3 in./5 in. Concentric
Front Panel View
Side Panel View
Rinnai Tankless Water Heater Installation and Operation Manual 13
Connection Connection Size
Gas 3/4 in. NPT
Cold Inlet 3/4 in. NPT
Hot Outlet 3/4 in. NPT
Condensate Drain 1/2 in. NPT
Figure 5: Supply Connections
Table 3. Supply Connections
14 Rinnai Tankless Water Heater Installation and Operation Manual
Numerous optional accessories are available for purchase for your Rinnai Tankless Water Heater.
Listed below are some commonly purchased accessories. For a complete list of accessories, visit
www.rinnai.us. For questions, or to purchase an accessory, contact your local Rinnai dealer/
distributor or Rinnai Customer Care at 1-800-621-9419.
Table 4. Accessories
Product Product Description Image
Isolation Valve Kit
• Part #: MIVK-T-LW
Isolation valves provide the ability to
isolate the water heater from the
structure’s plumbing system and allow
quick and easy access to flush the
heat exchanger. Rinnai strongly
recommends use of these valves for
service and maintenance.
Outdoor Vent Cap
• Part #: RXOVC
Allows the water heater to be installed
outdoors.
BLE Push Button
• Part #: RPB02
Mounted in a convenient location, such
as a kitchen faucet or bathroom sink,
the BLE push button works without the
Wi-Fi Module to operate the tankless
water heater recirculation system by
pushing the button.
Thermal Bypass Valve
• Part #: 107000143
Included with RXP (with
pump) models
The thermal bypass valve can be
installed between a cold water pipe and
a hot water pipe to run recirculation
without a dedicated return line.
Condensate Neutralizer
• Part #: 804000074
Neutralizes the condensate generated
by the water heater.
Wi-Fi Module (and
Accessories)
• Part #: RWM101
Controls On-Demand recirculation,
remotely adjust temperatures, and
communicates with the service provider
portal. The module and MC-195T-US
controller are not compatible
accessories and must not be installed
together.
Additional Controllers
• Part #: MC-601-BK,
MC-601-W, or MC-
195T-US
Additional controllers are available for
user convenience.
Pipe Cover
• PCD11-SHS
Encloses the piping below the water
heater for aesthetic purposes.
Recess Box
• Part #: RGBCTWHRX
Allows a water heater to be recessed
into a wall. A vent adapter is provided
with the recess box.
Pressure
Relief
Valve
Rinnai Tankless Water Heater Installation and Operation Manual 15
Table 4. Accessories (Continued)
Product Product Description Image
ScaleCutter
• Part #: 103000038
Filters and reduces the amount
of scale entering the water
heater allowing for greater
water heater longevity.
ScaleCutter Refill Cartridge
• Part #: 103000039
Refill cartridge for the ScaleCutter
filter assembly.
Drain Down Kit
• Part #: 104000059
Provides freeze protection by
immediately draining the water
heater upon loss of power.
Leak Detection Kit
• Part #: RXLeakKit
Pipe cover drain pan and float
switch for use with Pipe Cover
(Part #: PCD11-SHS)
Room Air Screen
• Part #: 108000104 for 2 in.
• Part #: 108000105 for 3 in.
Recommended room air screen for
use in room air applications only.
EZConnect™ Cable
• Part #: REU-EZC-2
Electronically connects two water
heaters and allows them to
function as one hot water source.
OPU Switch
• Part #: REU-OPU3
Normally Closed (NC) switch that
connects to the tankless water
heater PC Board. When used with
a hydronic air handler, the switch
gives priority to domestic hot
water.
Dedicated Return and Isolation
Valve Kit
• Part #: 107000639
Valve kit including tee, drain valve,
pressure relief valve, check valve
and isolation valves (cold and hot)
to simplify set-up of a dedicated
recirculation line.
Internal Add-on Recirculation
Conversion Kit
• Part #: RX2RXPCK
Allows a no pump model to be
converted to a pump model.
Image not shown
Ubbink 2 in. Polypropylene
(PP) Flexible Venting
• Approved for condensing,
vertical non-direct vent (room
air) applications
• Maximum equivalent length:
50 ft (15 m)
Gas Conversion Kit
Part #:
• 104000330
Converts the tankless water heater
gas type. Kit contains gas
conversion manual and conversion
rating plate label (adheres to water
heater to display new gas type).
Sample Rating Plate Label
2 in. (60)
Flex Connector
Part #: 222720NPP
2 in. (60)
Condensing
Flex
Termination
Kit
Part #:
184470NPP
2 in. (60) Flex Roll X
41.5 Ft (12.5 m)
Part #: 222721NPP
16 Rinnai Tankless Water Heater Installation and Operation Manual
Topics in this section
• Installation Guidelines
• What You will Need
• Choose an Installation Location
• Mount the Water Heater to the Wall
• Vent the Water Heater
• Connect the Water Supply
• Install the Isolation Valves
• Install the Pressure Relief Valve
• Connect the Condensate Drain
• Connect the Gas Supply
• Connect the Power Supply
• Initial Settings
• Configure Parameter Settings
• External Pump with Circ-Logic
• Post-Water Heater Installation Checklist
When installing the water heater, follow these
guidelines:
• This water heater is certified for installation
in residential applications and manufactured
(mobile) homes.
• This water heater is suitable for combination
water heating and space heating and not
suitable for space heating applications only.
• The installation must conform with local
codes or, in the absence of local codes, with
the National Fuel Gas Code, ANSI Z223.1/
NFPA 54, and/or CSA B149.1, Natural Gas
and Propane Installation Code. If installed in
a manufactured home, the installation must
conform with the Manufactured Home
Construction and Safety Standard, Title 24
CFR, Part 3280 and/ or CAN/SCA Z240 MH
Series, Manufactured Homes.
THIS SECTION IS INTENDED FOR THE
INSTALLER
Installer qualifications: A trained and qualified
professional must install the appliance,
inspect it, and leak test the water heater
before use. The warranty may be voided due
to any improper installation. The trained and
qualified professional should have skills such
as: Gas sizing; Connecting gas lines, water
lines, valves, and electricity; Knowledge of
applicable national, state, and local codes;
Installing venting through a wall or roof; and
training in installation of tankless water
heaters. Training for Rinnai Tankless Water
Heaters is accessible online at
rinnaipro.myabsorb.com.
• The appliance, when installed, must be
electrically grounded in accordance with
local codes or, in the absence of local
codes, with the National Electrical Code,
ANSI/NFPA 70, and/or the CSA C22.1,
Canadian Electrical Code, Part 1.
• The appliance and its main gas valve must
be disconnected from the gas supply piping
system during any pressure testing of that
system at test pressures in excess of 1/2
psi (3.5 kPa) (13.84 in W.C.). The appliance
must be isolated from the gas supply piping
system by closing its individual manual
shutoff valve during any pressure testing of
the gas supplying system at test pressure
equal to or less than ½ psi (3.5 kPa) (13.84
in W.C.).
• You must follow the installation instructions
and those in section “4.5 Vent the Water
Heater” for adequate combustion air and
exhaust.
• If a water heater is installed in a closed
water supply system, such as one having a
backflow preventer in the cold water supply
line, means shall be provided to control
thermal expansion. Contact the water
supplier or local plumbing inspector on how
to control thermal expansion.
• Should overheating occur or the gas supply
fail to shut off, turn off the manual gas
control valve to the appliance.
(En cas de surchauffe ou si l’alimentation
en gaz ne s’arrête pas, fermez
manuellement le robinet d’arrêt de
l’admission de gaz.)
• Combustion air must be free of chemicals,
such as chlorine or bleach, that produce
fumes. These fumes can damage
components and reduce the life of your
appliance.
DO NOT
• DO NOT install the water heater outdoors
without the Rinnai outdoor vent cap (Part #
RXOVC).
• DO NOT install the water heater indoors
with the Rinnai outdoor vent cap (Part #
RXOVC)
• DO NOT install the water heater in an area
where water leakage of the unit or
connections will result in damage to the
area adjacent to the appliance or to lower
floors of the structure. When such locations
cannot be avoided, it is recommended that
a suitable drain pan, adequately drained, be
installed under the water heater. The pan
must not restrict intake air flow.
• DO NOT install the water heater in an area
with negative air pressure.
• DO NOT obstruct the flow of combustion
and ventilation air.
• DO NOT use chemically treated water (i.e.
chlorinated water or salt water for pools or
spas) in the appliance.
• DO NOT use substitute parts that are not
authorized for this appliance.
Rinnai Tankless Water Heater Installation and Operation Manual 17
ITEMS:
• Gloves
• Safety glasses
• Soap or gas leak detector solution
• Approved venting
• Teflon tape (recommended) or pipe compound
• Pipe insulation
• Heat tape
• Electrical wire
• Concrete wall anchors
• Optional pipe cover
• PVC glue/cement and primer
• 2 conductor 22 AWG wire for controller
• Wire nuts
• Single gang electrical box
• Isolation Valve and Pressure Relief Valve Kit
(Part #: MIVK-T-LW)
• Unions and drain valves
• Smart device (such as a Smartphone)
• Combustion analyzer (recommended)
TOOLS:
• Pipe wrenches (x2)
• Phillips Head screwdriver
• Wire Cutters
• Hammer drill with concrete bits
• Saw
• Threading machine with heads and oiler
• Core drill with diamond head
• Torch set
• Copper tubing cutter
• Steel pipe cutter
• Level
Unpack the Rinnai Tankless Water Heater package and verify the following contents are included. If
any items are missing, contact your local dealer/distributor or call Rinnai Customer Care at 1-800-
621-9419.
# Item
❶
Rinnai Tankless Water Heater
❷
Vent screens (x2) and vent screen
screws (x2). The vent screen prevents
debris and other objects from entering
the terminal. One vent screen is for the
air inlet; the other is for the exhaust.
❸
Wall Mounting Bracket
❹
Self-Tapping Screws (x4) (4.2 x 25 mm)
❺
Gas Conversion Label
❻
Thermal Bypass Valve
For RXP (with pump) models only
❼
Literature Bag (image not shown)
• Wall Mounting Bracket Template
• Tankless Water Heater Installation
and Operation Manual (this manual)
❶
❷
❸
❹
❺
❻
18 Rinnai Tankless Water Heater Installation and Operation Manual
*Source: Part 143 National Secondary Drinking Water Regulation
Table 5. Water Quality Guidelines
This section provides information on the
importance of water quality to the Rinnai
Tankless Water Heater. The information is
intended to serve as a general guide only
and is not a complete list of water quality
guidelines. Consideration of care for your
water heater should include evaluation of
water quality. The water must be potable,
free of corrosive chemicals, sand, dirt, or
other contaminants. It is up to the trained
and qualified professional to ensure the
water does not contain corrosive chemicals
or elements that can affect or damage the
Rinnai Tankless Water Heater. Water that
contains chemicals exceeding the levels
listed below can damage the Rinnai
Tankless Water Heater. Replacement of
components due to water quality damage is
not covered by the warranty.
If you install this water heater in an area that
is known to have hard water or that causes
scale build-up, the water must be treated
and may require a more frequent flushing
schedule. This water heater includes a
service indicator: Service Soon, SS (see
section “4.13 Configure Parameter Settings”
for instructions on adjusting parameter
settings). When selected in the parameter
settings, an SS code will display on the
controller indicating that it is time to flush
and service the water heater. Scale build-up
is caused by hard water and can be
accelerated if the water heater is set at a
high temperature. Rinnai offers
Southeastern Filtration’s “ScaleCutter Water
Conditioning System” that offers superior
lime scale prevention and corrosion control.
Refer to section “3.6 Accessories” for more
information.
When selecting an installation location, you
must ensure that all water heater and venting
clearances will be met and that the vent length
will be within required limits. Consider the
installation environment, water quality, and the
need for freeze protection. Requirements for
the gas line, water lines, electrical connection,
and condensate disposal can be found in their
respective installation sections in this manual.
• Air surrounding the water heater, venting, and vent
termination(s) is used for combustion and must be
free of any compounds that cause corrosion of
internal components.
• These include corrosive compounds that are found
in aerosol sprays, detergents, bleaches, cleaning
solvents, oil-based paints/varnishes, and
refrigerants. The air in hair/nail salons, spas, dry
cleaning stores, photo processing labs, and storage
areas for pool supplies often contains these
compounds. Therefore, it is recommended that
external (outdoor) installations be used for these
locations where possible. In applications utilizing
room air where there are high levels of particulates,
Rinnai offers a room air screen.
• The water heater, venting, and vent termination(s)
should not be installed in any areas where the air
may contain these corrosive compounds.
• Install the water heater as far away as possible from
any air inlet vents. Corrosive fumes, sometimes
found in hair/nail salons, spas, or other industries
exposed to toxic fumes, may be released through
these vents when not in operation. Chemicals that
are corrosive in nature should not be stored or used
near the water heater or vent termination. This
requirement applies to indoor and outdoor
installations.
• In coastal regions, the water heater should be
installed so that it is sheltered/protected from
exposure to sea breeze. Exposure to salty spray or
breeze can cause corrosion of the water heater.
• DO NOT install the water heater in areas where
intake air might be contaminated with chemicals.
• DO NOT use room air in applications where the
indoor air is corrosive. Install the water heater as
direct vent in a sealed closet so that it is protected
from the potential of contaminated indoor air.
• Install the water heater and/or vent termination as
far away as possible from exhaust vent hoods and
dryer vents.
• Damage and repair due to corrosive compounds in
the air is not covered by warranty.
Contaminant Maximum Level
Total Hardness Up to 200 mg/L
Aluminum * Up to 0.2 mg/L
Chlorides * Up to 250 mg/L
Copper * Up to 1.0 mg/L
Dissolved Carbon Dioxide (CO2) Up to 15.0 mg/L
Iron * Up to 0.3 mg/L
Manganese * Up to 0.05 mg/L
pH * 6.5 to 8.5
TDS (Total Dissolved Solids) * Up to 500 mg/L
Zinc * Up to 5 mg/L
Rinnai Tankless Water Heater Installation and Operation Manual 19
Make sure that in case of freezing weather the water heater and its water lines are protected to
prevent freezing. Damage due to freezing is not covered by the warranty.
When connected to a 120-volt power supply, the water heater will not freeze when the outside air
temperature is as cold as -22°F (-30°C) for indoor installations or -4°F (-20°C) for outdoor
installations, when protected from direct wind exposure. Because of the “wind-chill” effect, any wind
or circulation of the air on the water heater will reduce its ability to protect itself from freezing.
In the event of a power failure and/or gas interruption at temperatures below freezing, the water
heater should manually be drained of all water to prevent freezing damage. In addition, drain the
condensate trap, drain line and pressure relief valve.
Loss of freeze protection may result in water damage from a burst heat exchanger or water lines.
The water heater may be drained manually. However, it is highly recommended to install the optional
Drain Down Kit accessory (part # 104000059) that will enable the water heater to immediately drain
upon loss of power (the condensate trap is not affected by the Drain Down Kit and must be manually
drained). Refer to section “3.6 Accessories” for more information on the Drain Down Kit.
The freeze protection features will not prevent the external piping and valves from freezing. It is
recommended that hot and cold water pipes be insulated. Pipe cover enclosures may be packed
with insulation for added freeze protection.
Figure 6: Freeze Protection Piping Diagram
Freeze Protecon Piping Diagram
Vacuum Breaker
1/2 in. Normally Open Solenoid Valve
Route Drain Per Local Code
Hot Water
Supply Line
Cold Water
Supply Line
3/4 in. Normally Closed Solenoid Valve
Legend
Vacuum Breaker
Pressure Relief
Valve Union
Drain Valve
Solenoid Valve
Ball Valve
Check Valve
20 Rinnai Tankless Water Heater Installation and Operation Manual
Table 6. Clearances
The water heater is not exposed to corrosive compounds in the air.
The water heater location complies with the required clearances.
The planned intake air and exhaust termination locations meet the required clearances.
The water supply does not contain chemicals or exceed total hardness that will damage
the heat exchanger.
A standard 3 prong 120 VAC, 60 Hz properly grounded wall outlet or other 120 VAC, 60
Hz source is available.
The installation must conform with local codes or, in the absence of local codes, with the
National Electric Code (NEC), National Fuel Gas Code, ANSI Z221.3/NFPA 54, and/or
CSA B149.1, Natural Gas and Propane Installation Code.
Use this checklist to ensure you have selected the correct location for the water heater.
Figure 7: Clearances
Location Clearance to Combustibles and Non-Combustibles
Top 2 in. (51 mm) (0 in. from vent components)
Bottom/Ground 12 in. (305 mm)
Front 0 in. (Clearance for servicing is 24 in. / 610 mm in front of water heater)
Back 0 in.
Sides (Left and Right) 2 in. (51 mm) (Add 0.25 in. / 6.35 mm for recess box)
Vent 0 in.
TOP
BOTTOM
SIDE
FRONT
CAUTION
If clearances are not met, damage to the property and water heater
may occur.
Rinnai Tankless Water Heater Installation and Operation Manual 21
3. Insert the top bracket into the wall
mounting bracket. Make sure the wall
mounting bracket is attached to the wall
and can hold the weight of the water
heater before you fully let go.
2. Use four screws to secure the wall mounting
bracket to the wall (two screws on the far left
side and two screws on the far right side).
Use the appropriate screws for the wall
construction to secure the mounting bracket
to the wall between two studs.
Figure 9: Secure the bracket
You Will Need:
• Rinnai Tankless Water Heater
• Wall Mounting Bracket
Supplied by Installer:
• Level
• Minimum of 6 screws (more screws may
be needed depending on wall type)
Use appropriate screws for type of wall
constructions.
Instructions:
1. Hold the wall mounting bracket up against
the wall and use a level to make sure the
bracket is even. Proper operation requires
the water heater to be level.
Figure 8: Level the bracket
Figure 10: Mount the top bracket
22 Rinnai Tankless Water Heater Installation and Operation Manual
4. Securely screw the top and bottom brackets into the wall, making sure the screws are flush with
the wall.
• Use any of the holes in the top and bottom brackets.
• Make sure the securing method is sufficient to support the weight of the water heater. Refer
to the water heater weight in section “3.4 Specifications.”
IMPORTANT
The water heater must be installed in an upright position. Do not install the water
heater upside down or on its side or back.
Top
Bracket
Bottom
Bracket
Figure 11: Top and Bottom Bracket
5. Pour approximately 10 ounces (1.25 cups) of water directly into the water heater’s exhaust port.
Before operation of the water heater, the condensate collector must be filled with water. This is to
prevent the potential of exhaust gases from entering the building. Failure to fill the condensate
collector could result in severe personal injury or death.
WARNING
Rinnai Tankless Water Heater Installation and Operation Manual 23
• The vent piece connected to the water
heater must be secured with 1 self-tapping
screw.
• Refer to the instructions of the vent system
manufacturer for component assembly
instructions.
• If the vent system is to be enclosed, it is
suggested that the design of the enclosure
shall permit inspection of the vent system.
The design of such enclosure shall be
deemed acceptable by the trained and
qualified professional or the local
inspector.
• Any issues resulting from improper vent
installation will not be covered by warranty.
• When an existing Category I appliance is
replaced by this tankless water heater, the
original venting system may not be
suitable for Category IV appliance.
Approved vent materials must be used.
• Internal water heaters can be installed as
direct vent or non-direct vent applications.
• When installed as Direct Vent, refer to the
“Direct Vent Approved Vent Manufacturers
and Products” section (within section “4.5.4
1. Direct Vent”) for a complete list of
approved vent manufacturers and products.
• When installed as Non-Direct Vent (Room
Air), the vent must be Category IV, listed by
a national recognized testing agency or
solid core schedule 40 PVC when accepted
by local codes.
• When installed as Non-Direct Vent
(outdoor), the Rinnai specified outdoor vent
cap must be used.
• Exhaust must be directly vented to the
outside. Intake air can be provided from
outside (Direct Vent) or from room air (Non-
Direct Vent).
• If using room air (non-direct vent) for
combustion, ensure the required volume of
indoor air is available in accordance with
one of the following:
A. The National Fuel Gas Code, ANSI
Z223.1/NFPA 54;
B. CSA B149.1, Natural Gas and Propane
Installation Code; or
C. Applicable provisions of the local
building code.
• Avoid dips or sags in horizontal vent runs
by installing supports per the vent
manufacturer’s instructions.
• Support horizontal vent runs every 4 ft (1.2
m) and all vertical vent runs every 6 ft (1.83
m) or as per vent manufacturer’s
instructions or local code requirements.
• Venting should be as direct as possible with
a minimum number of pipe fittings.
• For manufactured vent systems, vent
connections must be firmly pressed
together so that the connections form an air
tight seal. Follow the venting
manufacturer’s instructions.
• Refer to the PVC/CPVC manufacturer for
appropriate fittings, solvents or joining
methods.
• DO NOT use cellular core PVC/CPVC.
• DO NOT use Radel®
(polyphenylsulfone) or galvanized
material to vent this appliance.
• DO NOT cover non-metallic vent pipe
and fittings with thermal insulation.
• DO NOT combine vent components
from different manufacturers.
• You can reduce the vent diameter from
3 to 2 inch. Vent diameter cannot be
less than 2 in. (51 mm).
• DO NOT connect the venting system
with an existing vent or chimney.
• DO NOT common vent with the vent
pipe of any other manufacturer’s water
heater or appliance.
• Rinnai water heaters can only be
common vented with Schedule 40
PVC/CPVC or with a Rinnai certified
common vent system.
WARNING
IMPORTANT
If reusing existing venting, the venting should
be inspected for damage and to ensure it is
appropriate (approved) for this water heater.
To ensure safe and proper operation,
damaged vent components MUST be
replaced before operating the water heater.
24 Rinnai Tankless Water Heater Installation and Operation Manual
1. Install the water heater.
2. Determine the vent termination method—
horizontal or vertical, concentric, or twin
pipes, etc.
3. Determine proper location for wall or roof
penetration for each termination.
4. Install termination assembly as described
in this manual or in the vent
manufacturer’s installation instructions.
5. Install intake air and exhaust vent piping
from water heater to termination.
6. Slope horizontal exhaust run towards the
water heater 1/4 in. per foot (21 mm per
meter). DO NOT slope intake air pipe
towards water heater.
7. Install vent supports and brackets allowing
for movement from expansion, as per vent
manufacturer’s instructions or local code
requirements.
8. Install vent screen (supplied with water
heater) on PVC intake air and exhaust
termination elbows as illustrated below.
• Press vent screen inside of
termination piece/elbow.
• Secure vent screen to the elbow with
screw provided.
Check to determine whether local codes
supersede the following clearances:
•
Avoid termination locations near a dryer
vent.
•
Avoid termination locations near
commercial cooking exhaust.
•
Avoid termination locations near any air
inlets.
•
You must install a vent termination at
least 12 in. (30 cm) above the ground or
anticipated snow level.
The vent for this appliance shall not
terminate:
•
Over public walkways.
•
Near soffit vents or crawl space vents or
other areas where condensate or vapor
could create a nuisance or hazard or
cause property damage.
•
Where condensate or vapor could cause
damage or could be detrimental to the
operation of regulators, pressure relief
valves, or other equipment.
Listed below are important considerations for
locating vent termination under a soffit
(ventilated or unventilated or eave vent; or to
a deck or porch):
•
Do not install vent termination under a
soffit vent such that exhaust can enter the
soffit vent.
•
Install vent termination such that exhaust
and rising moisture will not collect under
eaves. Discoloration to the exterior of the
building could occur if installed too close.
•
Do not install the vent termination too
close under the soffit where it could
present recirculation of exhaust gases
back into the intake air part of the
termination.
Figure 12: Vent Screen
Rinnai Tankless Water Heater Installation and Operation Manual 25
Two types of venting options are available:
Room Air (Indoor)
Room air is used for
combustion while exhaust
vents to the outside.
External (Outdoor)
Concentric Pipe (Indoor)
Intake air and exhaust vent
directly through a single
concentric connection. Hot
exhaust exits through the
interior tube, while intake air
enters through the outer
layer.
Twin Pipe (Indoor)
Intake air and exhaust
vent directly through
separate penetrations.
Water heater with
outdoor vent cap.
Direct Vent
Multiple water heaters sharing an air intake
header and a separate exhaust header that
vents directly through separate penetrations to
the outside
Non-Direct (Room Air) Vent
Multiple water heaters using room air for
combustion while sharing an exhaust header
that vents directly to the outside.
26 Rinnai Tankless Water Heater Installation and Operation Manual
1. Direct Vent (Concentric Pipe and Twin Pipe)
Following is a list of vent components and terminations for Direct Vent installations. Install the
correct venting for your model according to the venting manufacturer’s instructions and the
guidelines below. The information below is correct at time of publication and is subject to change
without notice. Contact the vent manufacturer for questions related to the vent system, products,
part numbers and instructions.
Direct Vent Approved Vent Manufacturers and Products
Ubbink 800-621-9419
www.rinnai.us
Centrotherm 877-434-3432
www.centrotherm.us.com
Heat-Fab 800-772-0739
www.heaab.com
Metal Fab 800-835-2830
www.metal-fabinc.com
IPEX U.S.: 800-463-9572
Canada: 866-473-9462
www.ipexamerica.com
www.ipexinc.com
DuraVent 800-835-4429
www.duravent.com
Royal 800-232-5690
www.royalbuildingproducts.com
Ecco Manufacturing 877-955-4805
www.eccomfg.com
DiversiTech 800-995-2222
www.diversitech.com
Table 7. Approved Vent Manufacturers
Table 8. Approved Vent Products
2 in. /4 in. CONCENTRIC VENT TERMINATIONS
US/Canada
229031/229012NPP
2/4 Condensing Horizontal Terminaon Kit 12 in.
5
US/Canada
229032/229013NPP
2/4 Condensing Horizontal Terminaon Kit 21 in.
5
224359/224356NPP
2/4 Condensing Roof Discharge Terminaon 20
in. above roof
5
710202NPP
2/4 Condensing 90 Degree Diverter Nose
(Use with Wall Terminal)
5
710215NPP
2/4 Condensing 45 Degree Diverter Nose
(Use with Wall Terminal)
5
196005, 197040
FGV Concentric Vent Kit (16 in. length)
20
196005PVC
(Order from Rinnai)
196105, 197033
FGV Concentric Vent Kit (28 in. length)
20
196105PVC
(Order from Rinnai)
196125
FGV Concentric Vent Kit (40 in. length)
20
196125PVC
(Order from Rinnai)
Manufacturer
Manufacturer
Part Number
Product
Descripon
Diagram
Equivalent
Length ()
Vercal
Horizontal
UBBINK
IPEX
Rinnai Tankless Water Heater Installation and Operation Manual 27
2 in. /4 in. CONCENTRIC VENT TERMINATIONS (connued)
52CVKGS6502 PVC Concentric Vent Kit 2 in. x 16 in.
20
52CVKGVS6502-28 PVC Concentric Vent Kit 2 in. x 28 in.
20
52CVKGVS6502-40 PVC Concentric Vent Kit 2 in. x 40 in.
20
ICRT2439
2 in. x 4 in. Concentric Roof Terminaon
20
2PPS-VKL/VK-TCL
2 in. x 4 in. Vercal Terminaon Cap Kit
Concentric
20
2PPS-HKL
2 in. x 4 in. Horizontal Terminaon Kit
Concentric
20
190288
2 in. x 4 in. Concentric Horizontal Terminaon
5
190295
2 in. x 4 in. Concentric Vercal Terminaon
5
CVENT-2 2 in. Concentric Vent (Terminaon)
20
Manufacturer
Manufacturer
Part Number
Product
Descripon
Diagram
Equivalent
Length ()
Vercal
Horizontal
ROYAL
CENTROTHERM
DURAVENT
ECCO
DIVERSITECH
28 Rinnai Tankless Water Heater Installation and Operation Manual
3 in. /5 in. CONCENTRIC VENT TERMINATIONS
223174PP
223176PP
223177PP
3/5 Condensing Horizontal Terminaon Kit 8 7/10 in.
3/5 Condensing Horizontal Terminaon Kit 12 in.
3/5 Condensing Horizontal Terminaon Kit 21 in.
5
223186PP
3/5 Condensing Horizontal Diverter Terminaon Kit
19 in.
16
224047PP
3/5 Condensing Raised Horizontal Terminaon
Kit
24
184162PP
3/5 Condensing Roof Discharge Terminaon 20 in.
above roof
5
196006, 197009
FGV Concentric Vent Kit 3 in. x 20 in.
20
196006PVC
(Order from Rinnai)
196106, 197107
FGV Concentric Vent Kit 3 in. x 32 in.
20
196106PVC
(Order from Rinnai)
196116, 197117
FGV Concentric Vent Kit 3 in. x 44 in.
20
196116PVC
(Order from Rinnai)
52CVKGVS6503(PVC)/
52CVKGVSF9003(CPVC)
PVC/CPVC Concentric Vent Kit 3 in. x 20 in.
20
52CVKGVS6503-32(PVC)/
52CVKGVSF9003-32(CPVC)
PVC/CPVC Concentric Vent Kit 3 in. x 32 in.
20
52CVKGVS6503-44(PVC)/
52CVKGVSF9003-44(CPVC)
PVC/CPVC Concentric Vent Kit 3 in. x 44 in.
20
SC03HT
Horizontal Terminaon Adapter
20
SC03VT
Vercal Terminaon Adapter
20
ICRT3539
3 in./5 in. Concentric Roof Terminaon PPs-UV
20
Manufacturer
Manufacturer
Part Number
Product
Descripon
Diagram
Equivalent
Length ()
Vercal
Horizontal
UBBINK
IPEX
ROYAL
HEAT-FAB
CENTRO
THERM
Rinnai Tankless Water Heater Installation and Operation Manual 29
3 in. /5 in. CONCENTRIC VENT TERMINATIONS
(Connued)
3CGRLSV
Vercal Adapter
1
3CGRLSH
Horizontal Adapter
6
3CGRVT
Vercal Terminaon
5
3CGRHT
3 in. x 5 in. Horizontal Terminaon Cap Kit
Concentric
16
3PPS-VKL/VK-TCL
3 in. x 5 in. Horizontal Terminaon Cap Kit
Concentric
20
3PPS-HKL
3 in. x 5 in. Horizontal Terminaon Kit
Concentric
20
190388
3 in. x 5 in. Concentric Horizontal
Terminaon
5
190395 3 in. x 5 in. Concentric Vercal Terminaon
5
CVENT-3 3 in. Concentric Vent Terminaon
20
Manufacturer
Manufacturer
Part Number
Product
Descripon
Diagram
Equivalent
Length ()
Vercal
Horizontal
METAL
-FAB
DURAVENT
ECCO
DIVERSITECH
30 Rinnai Tankless Water Heater Installation and Operation Manual
2 in. TWIN PIPE TERMINATIONS
223085NPP
2 in. (60) Condensing Wall Terminal
Twin Pipe
10
ISELL0287UV
2 in. 87° Long PPS-UV
6
ISTT0220
2 in. Terminaon Tee
6
ISLPT0202
2 in. Low Prole Wall Terminaon
5
2PPS-HTPL
2 in. Twin Pipe Terminaon
10
2PPS-HSTL
2 in. Single Horizontal Terminaon
6
2PPS-TBL
2 in. Black UV Resistant Tee
5
196984
FGV PVC Low Prole Terminaon Kit
5
196984PVC
(Order from Rinnai)
081216
FGV PVC Wall Terminaon Kit
16
52SWVKGVS6502
PVC Side Wall Vent Kits
5
52WTVKGVS6502
PVC Wall Vent Kits
16
HVENT-2 2 in. Low Prole Horizontal Vent Kit
5
Manufacturer
Manufacturer
Part Number
Product
Descripon
Diagram
Equivalent
Length ()
Vercal
Horizontal
UBBINK
CENTROTHERM
DURAVENT
IPEX
ROYAL
DIVERSITECH
Rinnai Tankless Water Heater Installation and Operation Manual 31
3 in. TWIN PIPE TERMINTIONS
ISELL0387UV
3 in. 87° Long PPS-UV
6
ISTT0320
3 in. Terminaon Tee
6
ISLPT0303
3 in. Low Prole Wall Terminaon
5
3PPS-HTPL
3 in. Twin Pipe Terminaon
10
3PPS-HSTL
3 in. Single Horizontal Terminaon
5
3PPS-TBL
3 in. Black UV Resistant Tee
6
196985
FGV PVC Low Prole Terminaon Kit
5
196985PVC
(Order from Rinnai)
081219
FGV PVC Wall Terminaon Kit
16
52SWVKGVS6503
PVC Side Wall Vent Kits
5
52WTVKGVS6503
PVC Wall Vent Kits
16
HVENT-3 3 in. Low Prole Horizontal Vent Kit
5
Manufacturer
Manufacturer
Part Number
Product
Descripon
Diagram
Equivalent
Length ()
Vercal
Horizontal
CENTROTHERM
DURAVENT
ROYAL
IPEX
DIVERSITECH
32 Rinnai Tankless Water Heater Installation and Operation Manual
Table 9. Various 2 in. or 3 in. Schedule 40
PVC/ CPVC Terminations
Vent Screen
N/A N/A
Tee 5 5
90° Elbow 6 5
45° Elbow 3 2.5
Table 10. Acceptable and
Not Acceptable Elbows
Acceptable Acceptable
Not
Acceptable
90° Elbows,
Long Sweep
90° Elbows,
Short Sweep
90° Elbows,
Close Turn
Table 11. Approved PVC/CPVC Vent and Air Piping Material
Approved PVC/CPVC Vent and Air Piping Material
Item
Material
Standard for Installation in North America
United States Canada
Thermoplastic Piping Materials
Air Intake and Exhaust
Pipe and Fittings
PVC Schedule 40 ANSI/ASTM D1785
Thermoplastic vent pipe
must be certified to ULC
S636. Intake pipe may
be of the materials listed
in this table.
PVC-DWV ANSI/ASTM D2665
CPVC Schedule 40 ANSI/ASTM F441
PVC Pipe Cement and
Primer
PVC ANSI/ASTM D2564
CPVC Schedule 40 ANSI/ASTM F493
Non-Metallic Vent Material
Vent or Air Intake Pipe
and Fittings
ABS SCH 40 DWV
ASTM-D2661 or CSA
B181.1
NOT PERMITTED
(FOR EXHAUST)
PVC Vent Screens
Termination Vent
Screens
Polyethylene
2 in. Vent Screens (included in carton box)
(IPEX Part Number: 196050)
3 in. Vent Screens (IPEX Part Number: 196051)
Exhaust piping must be of solid core material. Refer to the PVC/CPVC manufacturer for
appropriate ngs, solvents or joining methods.
Table 12. Approved Venting Materials By Manufacturer
Manufacturer Vent Material
Ubbink PVC (Outer Vent), Polypropylene (Inner Vent)
Centrotherm Polypropylene
Heat-Fab Stainless Steel
Metal Fab Galvanized steel (Outer Vent), Stainless Steel (Inner Vent)
IPEX PVC/CPVC
DuraVent Polypropylene
Royal PVC
ECCO Manufacturing Polypropylene
DiversiTech PVC/CPVC
Product
Descripons
Diagram
Horizontal
Vercal
2 in.
Equivalent
Length
3 in.
Equivalent
Length
Rinnai Tankless Water Heater Installation and Operation Manual 33
I
Regulator vent outlet. In the event no regulator
is present, H and I can be disregarded.
The information below applies to Concentric and Twin Pipe:
V
Figure 13: Direct Vent Termination Clearances
Canadian Installations
1
(CSA B149.1)
U.S. Installations
2
(ANSI Z223.1/NFPA 54)
Ref Description Direct Vent (Indoor Unit) Direct Vent (Indoor Unit)
A Clearance above grade, veranda, porch, deck, or balcony 12 in. (30 cm) 12 in. (30 cm)
B Clearance to window or door that may be opened 36 in. (91 cm) 12 in. (30 cm)
C Clearance to permanently closed window * *
D
Vertical clearance to ventilated soffit, located above the
terminal within a horizontal distance of 2 ft (61 cm) from the
center line of the terminal
* *
E Clearance to unventilated soffit * *
F Clearance to outside corner * *
G Clearance to inside corner * 12 in.
H
Clearance to each side of center line extended above meter/
regulator assembly
3 ft. (91 cm) within a height of
15 ft. (4.6 m)
*
I Clearance to service regulator vent outlet 3 ft. 91 cm) *
J
Clearance to non-mechanical air supply inlet to building or
the combustion air inlet to any other appliance
36 in. (91 cm) 12 in. (30 cm)
K Clearance to a mechanical air supply inlet 6 ft (1.83 m)
3 ft (91 cm) above if within 10 ft
(3m) horizontally
L
Clearance above paved sidewalk or paved driveway located
on public property
7 ft (2.13 m) [1]
Vents for Category II and IV ap-
pliances cannot be located above
public walkways or other areas
where condensate or vapor can
cause a nuisance or hazard.
M Clearance under veranda, porch, deck, or balcony 12 in. (30 cm) [2] *
1
In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code.
2
In accordance with the current ANSI Z223.1/NFPA 54, National Fuel Gas Code.
If locally adopted installation codes specify clearances different than those illustrated, then the most stringent clearance shall prevail.
Clearance to opposite wall is 24 in. (60 cm).
[1] A vent shall not terminate directly above a sidewalk or paved drive-
way that is located between two single family dwellings and serves both
dwellings.
[2] Permitted only if veranda, porch, deck, or balcony is fully
open on a minimum of two sides beneath the floor.
*Clearances are in accordance with local installation codes
and the requirements of the gas supplier. (Dégagement
conforme aux codes d’installation locaux et aux exigences
du foumisseur de gaz.)
SNOW
TERMINATION
Table 13. Clearances
34 Rinnai Tankless Water Heater Installation and Operation Manual
1. Direct Vent (Concentric Pipe )
Concentric Pipe Overview
Intake air and exhaust vent directly through a
single concentric connection. Hot exhaust
exits through the interior tube, while fresh air
enters through the outer layer.
Exhaust
Figure 15: Concentric Pipe
Figure 16: Between terminals at different
levels
Figure 14: Concentric Pipe Termination
Clearances
Figure 17: Between terminals at same level
All terminations (horizontal and/or vertical) must terminate 12 in. (0.30 m) above grade or
anticipated snow level.
Intake
air
Intake
air
Rinnai Tankless Water Heater Installation and Operation Manual 35
Horizontal Wall
Terminations
Vertical Roof
Terminations
2 in. x 4 in. 2 in. x 4 in. and
3 in. x 5 in.
3 in. x 5 in.
Concentric Pipe: Installation
Instructions
1. Remove and discard screw from concentric
flue connection.
2. Remove exhaust adapter ring (discard for
concentric venting configurations.)
3. Install the concentric vent. Ensure it is
properly seated.
4. Secure the vent pipe to the concentric
flue connection with the supplied screws.
Mount Concentric Pipe Through Wall
If venting behind the unit through an exterior
wall, align the wall mounting bracket template
(located in literature bag) to the wall and follow
instructions on the template for appropriate vent
hole location. Use a level to make sure the wall
mounting bracket is even and level.
Table 15. Concentric Pipe: Maximum Vent Length
Install the venting termination according to
the diagrams and instructions in this manual.
Slope the venting 1/4 in. per foot (21 mm per
meter) toward the appliance according to the
vent manufacturer’s installation instructions.
Dispose of condensate per local codes.
IMPORTANT
Figure 19
Figure 22
Figure 18
Figure 21
Vent Sizes
2 in / 4 in
(51 mm/100 mm)
3 in / 5 in
(76 mm/125 mm)
Vent Lengths
75 ft (23 m) 150 ft (46 m)
45° Elbow
3 ft (1 m) 2.5 ft (0.7 m)
90° Elbow
6 ft (2 m) 5 ft (1.5 m)
Table 14. Terminations
Level
Wall
Mounting
Bracket
Wall
Mounting
Bracket
Template
Figure 20
Concentric
vent
36 Rinnai Tankless Water Heater Installation and Operation Manual
1. Direct Vent (Twin Pipe )
Twin Pipe Overview
Intake air and exhaust vent directly through separate penetrations.
Intake Air
Exhaust
12 in.
min
12 in.
min
12 in.
min
12 in.
min
60 in.
min
12 in.
min
Minimum clearance for
Ground/Grade/Snow Level
Indicates area in which intake
cannot be installed.
Figure 25: Horizontal Vent and Intake Air Piping
Figure 23
Twin Pipe Termination Clearances
Figure 24: Twin Pipe Vertical Termination of Multiple
Water Heaters
12 in. (0.30 m)
Minimum above
intake air
opening
Exhaust
Roof
Intake
Air
12 in. (0.30 m)
Above grade or
anticipated
snow level
Intake Air
Intake Air
Rinnai Tankless Water Heater Installation and Operation Manual 37
Twin Pipe Installation Instructions
The water heater is equipped with a 2 in. (51
mm) pipe connection. With the use of a pipe
reducer, installers can use a 3 in. (76 mm) pipe
for the Intake air and exhaust. In this case, a 2
in./3 in. pipe reducer should be installed as
close as possible to the water heater.
1. Remove and discard the screw from
the intake air vent connection.
2. Remove and discard the intake air vent
cap.
Supplied screws
4. Install the exhaust vent pipe. Ensure it is
properly seated.
Secure the exhaust vent pipe to the
exhaust adapter ring with the supplied
screws.
3. Install the intake air vent pipe. Ensure it is
properly seated.
Secure the intake air vent pipe to the intake
air vent connection with the supplied
screws.
DO NOT apply PVC glues, solvents, or
cleaners to the water heater’s intake air or
exhaust gasket connections. Failure to
correctly assemble the components
according to these instructions may result
in property damage, personal injury, or
death.
WARNING
Figure 26
Figure 27
Figure 28
Figure 29
1. Direct Vent (Twin Pipe )
Intake Air Vent Pipe
Exhaust
Supplied screws
38 Rinnai Tankless Water Heater Installation and Operation Manual
Twin Pipe Example Vent Applications
Slope horizontal exhaust 1/4 in. per foot (21 mm per meter) towards the water heater. DO NOT
slope intake air pipe towards the water heater.
This configuration requires the use of a
Concentric Vent Termination
This configuration requires the use of a
Concentric Vent Termination
2 in. or 3 in. PVC/ CPVC
IPEX/ Royal Concentric
Side Wall Termination
Configuration
2 in. or 3 in. PVC/CPVC
IPEX/ Royal Concentric
Vertical Termination
Configuration
2 in. or 3 in. Schedule
40 PVC/CPVC or ABS
Snorkel Termination
Configuration
2 in. or 3 in. Schedule 40
PVC/CPVC or ABS
Standard upside down “U”
Vertical Termination
Configuration
2 in. or 3 in. Schedule
40 PVC/CPVC or ABS
Elbow or Tee Side Wall
Termination Configuration
2 in. or 3 in. Schedule
40 PVC/CPVC or ABS
Tee Vertical Termination
Configuration
2 in. or 3 in.
PVC
Low Profile
Termination
Configuration
Exhaust and
intake air
MUST NOT be
brought
together into a
single PVC
pipe using
a pipe fitting.
Single
pipe
Exhaust
Intake air
Table 17. Twin Pipe Maximum Equivalent Length
Twin Pipe Maximum Vent Length
WARNING
Table 16
1. Direct Vent (Twin Pipe )
Vent Sizes 2 in. (51 mm) 3 in. (76 mm)
Vent Lengths
75 ft (23 m) 150 ft (46 m)
45° Elbow
3 ft (1 m) 2.5 ft (0.7 m)
90° Elbow
6 ft (2 m) 5 ft (1.5 m)
Rinnai Tankless Water Heater Installation and Operation Manual 39
2. Non- Direct Vent (Room Air and External )
Room Air and External Termination Clearances
Figure 30: Room Air and External
Termination Clearances
I
Regulator vent outlet. In the
event no regulator is present,
H and I can be disregarded.
V
Canadian Installations
1
(CSA B149.1)
U.S. Installtions
2
(ANSI Z223.1/NFPA 54)
Ref Description
Other than direct vent
(Outdoor unit and/or Room Air)
Other than direct vent
(Outdoor unit and/or Room Air)
A
Clearance above grade, veranda, porch,
deck, or balcony
12 in. (30 cm) 12 in. (30 cm)
B
Clearance to window or door that may be
opened
36 in. (91 cm)
4 ft (1.2 m) below or to side of
opening; 1 ft (300 mm) above opening
C Clearance to permanently closed window * *
D
Vertical clearance to ventilated soffit, located
above the terminal within a horizontal
distance of 2 ft (61 cm) from the center line of
the terminal
* *
E Clearance to unventilated soffit
* *
F Clearance to outside corner
* *
G Clearance to inside corner * 12 in.
H
Clearance to each side of center line
extended above meter/regulator assembly
3 ft. (91 cm) within a height 15 ft.
(4.6 m)
*
I Clearance to service regulator vent outlet 3 ft. (91 cm) *
J
Clearance to nonmechanical air supply inlet
to building or the combustion air inlet to any
other appliance
36 in. (91 cm)
4 ft (1.2 m) below or to side of
opening; 1 ft (300 mm) above opening
K Clearance to a mechanical air supply inlet 6 ft (1.83 m)
3 ft (91 cm) above if within 10 ft
(3 m) horizontally
L
Clearance above paved sidewalk or paved
driveway located on public property
7 ft (2.13 m) [1]
Vents for Category II and IV
appliances cannot be located above
public walkways or other areas where
condensate or vapor can cause a
nuisance or hazard.
M
Clearance under veranda, porch, deck, or
balcony
12 in. (30 cm) [2] *
Table 18
1
In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code.
2
In accordance with the current ANSI Z223.1/NFPA 54, National Fuel Gas Code.
If locally adopted installation codes specify clearances different than those illustrated, then the most stringent clearance shall prevail.
Clearance to opposite wall is 24 in (60 cm).
[1] A vent shall not terminate directly above a sidewalk or paved driveway that is
located between two single family dwellings and serves both dwellings.
[2] Permitted only if veranda, porch, deck, or balcony is fully open on a minimum
of two sides beneath the floor.
*Clearances are in accordance with local installation
codes and the requirements of the gas supplier.
(Dégagement conforme aux codes d’installation
locaux et aux exigences du foumisseur de gaz.)
SNOW
TERMINATION
40 Rinnai Tankless Water Heater Installation and Operation Manual
•
Installation of Non-Direct Vent (Room Air) must use listed category IV venting.
•
All terminations (horizontal and/or vertical) must terminate 12 in. (30 cm) above grade or
anticipated snow level.
Termination Clearances for External (Outdoor) Installations
Exhaust Termination Clearances for Internal (Indoor) Room Air Applications
NOTE
Figure 32
Figure 31
12 in.
(0.30 m)
Corner
36 in. (0.91 m) to ventilated or
unventilated soffit or eve vent; or
to a deck or porch
60 in. (1.52 m) vertically between terminals
12 in.
(0.30 m)
12 in. (0.30 m)
60 in. (1.52 m) vertically between terminals
Rinnai Tankless Water Heater Installation and Operation Manual 41
Room Air: Intake Air
For applications containing corrosive indoor air, this appliance must be installed as direct vent. DO
NOT use room air in applications where intake air contains acid forming chemicals such as sulfur,
fluorine and chlorine. These chemicals have been found to cause rapid damage and decay and can
become toxic when used as intake air for gas appliances. Such chemicals can be found in, but not
limited to bleach, ammonia, cat litter, aerosol sprays, cleaning solvents, varnish, paint and air
fresheners. Do not store these products or similar products in the vicinity of this water heater.
Unconfined Space
An unconfined space is defined in National Fuel Gas Code, ANSI Z223.1/NFPA 54 as “a space
whose volume is not less than 50 cubic feet per 1000 Btu/hr (4.8 m³ per kW per hour) of the
aggregate input rating of all appliances installed in that space. Rooms communicating directly with
the space in which the appliances are installed, through openings not furnished with doors, are
considered a part of the unconfined space.” If the “unconfined space” containing the appliance(s) is
in a building with tight construction, additional outside air may be required for proper operation.
Outside air openings should be sized the same as for a confined space.
Confined Space
A confined space is defined in the National Fuel Gas Code, ANSI Z223.1/NFPA 54 as “a space
whose volume is less than 50 cubic feet per 1000 Btu/hr (4.8 m³ per kW per hour) of the
aggregate input rating of all appliances installed in that space.” Examples include a small room,
closet, alcove, utility room, etc. A confined space must have two intake air openings. Size the intake
air openings based on the BTU input for all gas utilization equipment in the space and the method by
which intake air is supplied.
Using Indoor Air For Combustion: When using air from other room(s) in the building, the total volume
of the room(s) must be of adequate volume (Greater than 50 cubic feet per 1000 Btu/hr). Intake air
openings between joining rooms must have at least 1 square inch of free area for each 1000 Btu/h,
but not less than 100 square inches each.
Using Outdoor Air For Combustion
Outdoor air can be provided to a confined space through two permanent openings, one commencing
within 12 in. (0.30 m) of the top and one commencing within 12 in. (0.30 m) of the bottom, of the
confined space. The openings shall communicate to the outside by one of two ways.
When communicating directly with the outdoors through horizontal ducts, each opening shall have a
minimum free area of 1 in.
2
/2000 Btu/hr (1100 mm
2
/kW) of total input rating of all appliances in the
confined space.
This water heater requires adequate air for ventilation and dilution of flue
gases. Failure to provide adequate air can result in unit failure, fire,
explosion, serious bodily injury or death. Use the following methods to ensure adequate air is
available for correct and safe operation of this water heater.
WARNING
IMPORTANT
Intake air must be free of corrosive chemicals. Do not provide air from corrosive environment.
Appliance failure due to corrosive air is not covered by warranty.
NOTE
If ducts are used, the cross sectional area of the duct must be greater than or equal to the
required free area of the openings to which they are connected.
42 Rinnai Tankless Water Heater Installation and Operation Manual
To prevent possible personal injury or death due to asphyxiation, common venting with other
manufacturer’s induced draft appliances is not allowed.
WARNING
Louvers and Grills
Adequate air is required for all gas utilizing equipment in the location. Therefore, proper sizing of
permanent openings, such as louvers or grills, must be considered to maintain the required free
area. If the free area of the louver or grill design is not available, assume wood louvers will have
25% free area and metal louvers or grills will have 75% free area. Under no circumstance should the
louver, grill or screen have openings smaller than 1/4 in.
Example for a grill with dimensions as shown in Figure 33:
Wood: 10 in. x 12 in. x 0.25 = 30 in.2
Metal: 10 in. x 12 in. x 0.75 = 90 in.2
12 in.
(300 mm)
10 in.
(250 mm)
Location
To maintain proper circulation of air, two permanent
openings (one upper, one lower) must be positioned
in confined spaces. The upper shall be within 12 in.
(0.30 m) of the top of the confined space and the
lower opening shall be within 12 in. (0.30 m) of the
bottom of the confined space. Openings must be
positioned as to never be obstructed.
Combustion air provided to the appliance should not
be taken from any area of the structure that may
produce a negative pressure (i.e. exhaust fans,
powered ventilation fans).
Checklist for Intake Air and Venting Requirements
□
Verify all combustion air opening sizes are correct.
□
Ensure that the combustion air requirements are followed that will provide sufficient
combustion air for the appliance.
□
DO NOT use room air for combustion in applications where the indoor air is corrosive.
□
Verify that adequate combustion air is available for all appliances installed in the space.
□
Installation complies with National Fuel Gas Code, ANSI Z223.1/NFPA 54 as well as local and
state regulations therein.
Figure 33
Rinnai Tankless Water Heater Installation and Operation Manual 43
1. Remove and discard screw from
combustion air vent connection.
2. Remove and discard the combustion
air vent cap.
3. Install the intake air pipe. Ensure it is
properly seated.
Secure the intake air pipe to the
combustion air vent connection with the
supplied screws.
Room Air: Installation Instructions
4. Place the vent screen or room air screen
inside elbow and secure with the supplied
screw. Use the room air screen for
environments where room air is dusty.
Notes:
• 2 in vent screen supplied with
water heater.
• Room air screen is available as
an accessory.
Supplied screw
Elbow
Vent
screen
5. Install the exhaust vent pipe. Ensure it is
properly seated.
Secure the exhaust vent pipe to the exhaust
adapter ring with the supplied screws.
Figure 34
Figure 35
Figure 36
Figure 37
Figure 38
Intake Air Pipe
Supplied screws
Exhaust vent pipe
Supplied screws
44 Rinnai Tankless Water Heater Installation and Operation Manual
Room Air: Example Vent Applications
2 in. or 3 in.
Schedule 40
PVC/CPVC or
ABS Snorkel
Termination
Configuration
2 in. or 3 in.
Schedule 40
PVC/CPVC or
ABS Elbow or
Tee Side Wall
Termination
Configuration
2 in. or 3 in.
Schedule 40
PVC/CPVC or
ABS Standard
Upside Down
“U” Vertical
Termination
configuration
2 in. or 3 in.
Schedule 40
PVC/CPVC or
ABS Tee Verti-
cal Termination
Configuration
Slope horizontal exhaust 1/4 in. per
foot (21 mm per meter) towards the
water heater.
Room Air: Maximum Vent Length
Table 19. Room Air Maximum Equivalent Length
Vent Sizes
2 in. (51 mm) 3 in. (76 mm) 3 in. (76 mm) Ubbink Flex
Vent Length
75 ft (23 m) 150 ft (46 m)
50 ft. (15 m)
45° Elbow
3 ft (1 m) 2.5 ft (0.7 m)
90° Elbow
6 ft (2 m) 5 ft (1.5 m)
Ubbink flexible
venting approved for
vertical non-direct
vent (room air)
applications only.
Refer to the flex vent
manual for further
details.
PP Flex
Venting
Rinnai Tankless Water Heater Installation and Operation Manual 45
Table 20
Room Air: Manufactured (Mobile) Home
• Combustion air must not
be supplied from occupied
spaces of the
manufactured home.
Access panels, doors or
opening of any kind are not
permitted between the
installation enclosure and
the inside of the
manufactured home.
• The installation enclosure
must include an exterior
access door incorporating
a single opening positioned
a maximum of 6 in. (152
mm) above the lower edge
of the door. The opening in
the access door must be
metal with no less than 1/4
in. (6.4 mm) mesh.
• The water heater is to be
secured to the wall of the
manufactured home using
the integrated mounting
brackets on the back side
of the water heater.
Use the following table to identify the minimum required
size of the opening in the access door.
Model Input
Btu/h
Example
Opening Size (LxH)
Minimum
Required Area
RX199i
RXP199i
199,000 20 in. x 10 in.
(508 mm x 254 mm)
200 in
2
(0.129 m
2
)
RX180i
180,000 180 in
2
(0.116 m
2
)
18 in. x 10 in.
(457 mm x 254 mm)
RX160i
RXP160i
160,000 160 in
2
(0.103 m
2
)
16 in. x 10 in.
(406 mm x 254 mm)
RX130i
130,000 130 in
2
(0.084m
2
)
13 in. x 10.
(330 mm x 254 mm)
Roof termination
Installation
Enclosure with
Louvered Door for
Manufactured
Home
Applications
Cold water Inlet
Pressure relief valve
Condensate
drain
Hot water Outlet
Gas supply
PVC Elbow with
Vent Screen
To suitable drain
Roof flashing
Top and Bottom
Mounting Bracket
Door
Louvered opening
6 in. (152 mm) Maximum
Figure 39
Pipe
Connections
on Bottom
of Water
Heater
Figure 40
For Installation in a Manufactured Home (Mobile Home)
46 Rinnai Tankless Water Heater Installation and Operation Manual
3. Common Vent (Indoor Units Only. Direct Vent and Non-Direct/Room Air Vent)
Common venting allows multiple Rinnai
Tankless Water Heaters to share the same
vent system. When operating multiple water
heaters in a common venting system, it is
recommended to use Rinnai’s EZConnect™
cable (purchased separately) which
electronically connects two water heaters so
they function as one hot water source.
Note: Multiple RXP models (water heaters with
a recirculation pump) cannot be electronically
connected using the EZConnect™ cable. The
EZConnect™ cable connects only an RXP
model with an RX model. See illustration
below.
Figure 41: Sample Inline, Freestanding
Configuration
Common Vent Maximum Equivalent Vent Lengths
Common vent equivalent lengths include
polypropylene pipe (PP) or PVC in a back-to
-back or inline configuration.
For the table below:
• Header is the main vent pipe into which
several vents connect.
• Vent Length is the distance from the end
of the header to the vent termination
• Maximum vent length starts at the end of
the header system.
Header
Vent length
Figure 42
Table 22. Common Vent Maximum Vent Length
Water Heater Model
# Water
Heaters
Max System Btu/hr
Vent Diameter
3 in. 4 in. 6 in.
RX199i, RXP199i 2 398,000
65 ft
(20 m)
150 ft
(46 m)
150 ft
(46 m)
RX180i 2 360,000
RX160i, RXP160i 2 320,000
90 ft
(27 m)
150 ft
(46 m)
150 ft
(46 m)
RX130i 2 260,000
Primary Secondary
Correct
RXP199i (With Pump) RX199i (Without Pump)
RX199i (Without Pump) RX199i (Without Pump)
RXP199i (With Pump) RXP199i (With Pump)
Not Correct
RX199i (Without Pump) RXP199i (With Pump)
Table 21. Primary and Secondary Water Heaters
Note: For common venting three or more units, refer to the “Common Vent Installation Instructions.”
Rinnai Tankless Water Heater Installation and Operation Manual 47
• The piping (including soldering materials) and components connected to this appliance must be
approved for use in potable water systems.
• Purge the water line to remove all debris and air. Debris will damage the water heater.
• The appliance must not be connected to a system that was previously used with a non-potable
water heating appliance.
• Ensure that the water filter on the water heater is clean and installed.
• DO NOT introduce toxic chemicals such as those used for boiler water treatment to the potable
water used for space heating.
• Verify water pressure meets requirements.
To connect the water supply, follow the instructions below.
Water connections to the water heater should follow all state and local plumbing codes. If this is a
standard installation, refer to the “Piping Diagram for Basic Installation” below.
1. Plumb the cold water supply line to the water heater on the 3/4 in. MNPT connection at the
bottom of the water heater marked “COLD.”
2. Plumb the hot water supply line to the 3/4 in. MNPT connection marked “HOT.”
3. If a pipe cover will be installed, make sure water lines to the water heater fit within the
confinements of the pipe cover.
PIPING DIAGRAM FOR BASIC INSTALLATION
KEY
This is not an engineered drawing. It is intended only
as a guide and not as a replacement for
professionally engineered project drawings. This
drawing is not intended to describe a complete
system. It is up to the contractor/engineer to
determine the necessary components and
configuration of the particular system being installed.
This drawing does not imply compliance with local
building code requirements. It is the responsibility of
the contractor/engineer to ensure installation is in
accordance with all local building codes. Confer with
local building officials before installation.
3/4" Ball Valve
3/4" Union
Check Valve
Pressure Relief
Valve
Pressure Regulator
Circulating Pump
Boiler Drain Valve
Solenoid Valve
S
Condensate
Drain
Line
Gas Supply
Cold water Supply line
Hot water Supply line
IMPORTANT
The condensate drain pipe (along its entire
length) must be at least the same diameter
as the drain line (1/2 in. NPT).
Refer to section “4.9 Connect Condensate
Drain” for more information.
Figure 43
48 Rinnai Tankless Water Heater Installation and Operation Manual
Isolation valves are not supplied with the water
heater, but it is highly recommended to install
the isolation valves. The isolation valves (part
number MIVK-T-LW) provide the ability to
isolate the water heater from the structure’s
plumbing and allow quick and easy access to
flush the heat exchanger. The isolation valves
must meet American National Standard (ANSI
Z21.10.3) / Canadian Standard (CSA 4.3).
Water discharged
from the pressure
relief valve could cause severe burns
instantly or death from scalds.
An approved pressure relief valve is
required by the American National Standard
(ANSI Z21.10.3) for all water heating
systems and shall be accessible for
servicing. When connecting a pressure
relief valve, follow the guidelines below:
• The pressure relief valve must comply
with the standard for Relief Valves for
Hot Water Supply System, ANSI
Z21.22/CSA 4.4 or the ANSI/ASME
Boiler and Pressure Vessel Code
Section IV.
• The pressure relief valve must be rated
up to 150 psi and to at least the
maximum Btu/hr of the appliance.
• The discharge from the pressure relief
valve should be piped to the ground or
into a drain system per local codes.
• The pressure relief valve must be
manually operated once a year to check
for correct operation.
• The discharge line from the pressure
relief valve should pitch downward and
terminate 6 in. (152 mm) above drains
where discharge will be clearly visible.
WARNING
• The discharge end of the line shall be
plain (unthreaded) and a minimum of 3/4
in. nominal pipe diameter. The discharge
line material must be suitable for water at
least 180° Fahrenheit (82°C).
• The pressure relief valve must be
installed near the hot water outlet.
• The pressure relief valve is connected
below the appliance. DO NOT place any
other valve or shut off device between
the pressure relief valve and the water
heater.
• For safe operation of the water heater,
the pressure relief valve must not be
removed or plugged.
• If a pressure relief valve discharges
periodically, this may be due to thermal
expansion in a closed water supply
system. Contact the water supplier or
local plumbing inspector on how to
correct this situation. Do not plug the
pressure relief valve.
• The American National Standard (ANSI
Z21.10.3) does not require a combination
temperature and pressure relief valve for
this appliance. However, local codes may
require a combination temperature and
pressure relief valve.
• Protect pressure relief valve and
pressure relief valve discharge line from
freezing. Do not plug or restrict flow of
the pressure relief valve.
• DO NOT plumb the pressure relief valve
with the condensate drain; both must be
plumbed independently to drain.
• DO NOT plug the pressure relief valve
and do not install any reducing fittings or
other restrictions in the relief line. The
pressure relief line should allow for
complete drainage of the valve and the
line.
Pressure Relief Valve Maintenance:
For proper care of this approved pressure
relief valve, it is recommended that the valve
is manually operated once a year. In doing
so, it will be necessary to take precautions
with regard to the discharge of potentially
scalding hot water under pressure. Ensure
discharge water has a safe place to flow.
Contact with your body or other property may
cause damage or harm.
Rinnai Tankless Water Heater Installation and Operation Manual 49
To prevent condensate damage, follow these
guidelines:
• Do not plumb the condensate drain
with the pressure relief valve; both
must be plumbed independently to
drain.
• All condensate must drain and be
disposed of according to local codes.
• Use only corrosion resistant
materials for the condensate drain
lines such as PVC pipe or plastic
hose.
• The condensate drain pipe (along its
entire length) must be at least the
same diameter as the drain line (1/2
in. MNPT).
• Condensation drain lines installed in
areas that are subject to freezing
temperatures should be wrapped
with an approved supplemental heat
source. Install per manufacturer’s
instructions.
• Slope the condensate drain lines
toward the inside floor drain or
condensate pump.
• The end of the condensate drain
pipe should be open to the
atmosphere. The end should not be
under water or other substances.
• For external (outdoor) installations, to
minimize freezing of the condensate, run
the condensate drain line through an
interior wall or between insulation and an
interior wall.
• If a floor drain is not available or the drain
is above the level of the condensate drain,
a condensate pump should be installed.
• A condensate neutralizer kit (part number
804000074) is available from Rinnai. The
kit allows condensate to flow through
neutralizing media that raises the pH of the
condensate to a level that will help prevent
corrosion of the drain and public sewer
system. Refer to section “3.6 Accessories”
for more information.
• The condensate drain pipe should be as
short as possible and have a downward
pitch.
• Pour approximately 10 ounces (1.25 cups)
of water directly into the water heater’s
exhaust port.
• DO NOT connect the condensate drain line
with an air conditioning evaporator coil
drain.
• Water heaters have an
integrated condensate trap.
DO NOT install an external
condensate trap.
CORRECT NOT CORRECT
Pipe submerged
in water
Pipe open to
atmosphere
Water
Level
Water
Level
Figure 44
Figure 45
Pipe open to
atmosphere
Condensate pump
*Overflow bypass
Air Gap
* Safety overflow if condensate drain
becomes clogged.
50 Rinnai Tankless Water Heater Installation and Operation Manual
To connect the condensate drain pipe:
1. Apply thread sealant to 1/2 in. MNPT
condensate drain port.
2. Thread 1/2 in. NPT fitting onto
condensate drain port.
3. Follow the steps in the next section:
“Condensate Pump Safety Switch
Wiring” (if needed).
1/2 in. MNPT
Condensate Drain
The condensate pump (if installed) should
be wired to deactivate the water heater in
the event the condensate pump fails.
1. Disconnect power from the water heater.
2. Open the water heater cover and locate
two white wires labeled “To Condensate
Pump Safety Switch.”
Strip insulation off
both ends of wire
Cut off crimp
connectors
To Condensate Pump Safety Switch
Test Operation
1. Test the operation of the shut off switch by
unplugging the condensate pump and filling
the condensate reservoir with water until the
float switch closes the circuit.
2. Turn on the water heater.
3. Confirm the water heater displays diagnostic
code “25.”
4. Plug in the condensate pump in and confirm
condensate is flowing out of the reservoir.
5. Turn off the water heater by pressing the
“On/Off” button on the controller. Wait five
seconds then turn the power back on. This
will clear the diagnostic code.
IMPORTANT
The steps in this section must conform with
local codes and the guidelines established by
the National Electrical Code (NEC).
3. Cut crimp connectors off white wires and strip
the insulation off of the two ends.
4. Select an appropriate length of wire (18 AWG
or greater) and strip the insulation off the
ends. Follow the wiring guidelines
established by the National Electrical Code
(NEC).
5. With wire nuts or other approved wire
connectors, connect the “To Condensate
Pump Safety Switch” wires to the normally
open contacts on the condensate pump (see
image below).
6. Reconnect power to the water heater and
press the “On/Off” button on the controller.
Figure 46
Figure 47
Rinnai Tankless Water Heater Installation and Operation Manual 51
Condensate Pump Safety Switch Installation
Field-Supplied Wires
Condensate Pump (field-supplied)
should include internal safety switch
and power cord. Power cord must be
plugged into power source.
Safety switch wires connect to the NO
and COM contacts on the safety switch.
• NO - Normally Open
• NC - Normally Closed
• COM - Common (Neutral)
COM
NC
NO
Field-Supplied Wires
Safety switch Wires
To Condensate Pump
Safety Switch Wires
Wire Nut Connecting
Two Wires
Tankless Water Heater
Figure 48
52 Rinnai Tankless Water Heater Installation and Operation Manual
To connect the gas supply, follow the
instructions below:
1. Install a manual gas control valve in the
gas supply line to the water heater. A
union can be used on the connection
above the shut off valve for the future
servicing or disconnection of the water
heater.
2. Check the type of gas and gas supply
pressure before connecting the water
heater. If the water heater is not of the
gas type that the building is supplied
with, DO NOT connect the water heater.
Contact the dealer for the proper water
heater to match the gas type.
3. Check the gas supply pressure
immediately upstream at a location
provided by the gas company. Supplied
gas pressure must be within the limits
shown in section “3.4 Specifications”
with all gas appliances operating.
4. Before placing the appliance in
operation, all joints including the heater
must be checked for gas tightness by
means of soap, gas leak detector
solution, or an equivalent nonflammable
solution, as applicable. (Since some
leak test solutions, including soap and
water, may cause corrosion or stress
cracking, the piping shall be rinsed with
water after testing, unless it has been
determined that the leak test solution is
non-corrosive.)
5. Use approved connectors to connect
the water heater to the gas line. Purge
the gas line of any debris before
connection to the water heater.
6. Any compound used on the threaded
joint of the gas piping shall be a type
that resists the action of liquefied
petroleum gas (propane/LPG).
7. The gas supply line shall be gas tight,
sized, and so installed as to provide a
supply of gas sufficient to meet the
maximum demand of the water heater
and all other gas consuming appliances
at the location without loss of pressure.
If in doubt about the size of the gas
line, refer to the “Gas Pipe Sizing
Reference Tables” section on the next
page.
8. Perform a leak and pressure test prior
to operating the water heater. If a leak is
detected, do not operate the water
heater until the leak is repaired.
Gas connection 3/4 in.
MNPT connection
• A trained and qualified professional must
install the gas supply.
• Turn off 120V power supply.
• Turn off the gas.
• Gas is flammable. Do not smoke or
provide other ignition sources while
working with gas.
• Do not turn on the water heater or gas
until all fumes are gone.
• Confirm the gas type before connecting.
Failure to install correct gas type may
result in injury or damage to the unit.
WARNING
Figure 49
Rinnai Tankless Water Heater Installation and Operation Manual 53
The gas supply must be capable of handling
the entire gas load required at the location.
Gas line sizing is based on gas type, the
pressure drop in the system, the gas
pressure supplied, and gas line type. For gas
pipe sizing, refer to the National Fuel Gas
Code, ANSI Z223.1/NFPA 54, or the Natural
Gas and Propane Installation Code, CSA
B149.1
For some tables, you will need to determine
the cubic feet per hour of gas required by
dividing the gas input by the heating value of
the gas (available from the local gas
company). The gas input needs to include all
gas products at the location and the
maximum Btu usage at full load when all gas
products are in use.
Use the table for your gas type and pipe type
to find the pipe size required. The pipe size
must be able to provide the required cubic
feet per hour of gas or the required Btu/hour.
The information below is provided as an
example. The appropriate table from the
applicable code must be used.
A
Btu/hr
B
Btu/hr
Table 23: Gas Pipe Sizing Calculation Worksheet
Instructions: Enter values in empty boxes.
Rinnai Mode Gas Input:
Additional Appliance Total Gas Input:
Answer:
Heating Value of Gas:
A + B
(CFH) =
C
(CFH) =
(CFH) =
ft3 /hr
Cubic Feet Per Hour (CFH):
Natural Gas
Table 24: Pressure Drop 0.5 in. wc
Example
Rinnai Model Gas Input:
A 199,000 Btu/hr
Addional Appliance Total Gas Input:
B 65,000 Btu/hr
Heang Value of Gas:
C 1,000 Btu/ft3
Cubic Feet Per Hour (CFH):
A + B
Information in table
obtained from NFPA
54, ANSI Z223.1 -
2021.
Schedule 40 Metallic Pipe
Inlet Pressure: Less than 2 psi
Specific Gravity: 0.60
Nominal Pipe Size (in.)
1/2 3/4 1 1 1/4
Length in ft
(meters)
Capacity in Cubic Feet of Gas per Hour
10 (3) 172 360 678 1,390
20 (6) 118 247 466 957
30 (9) 95 199 374 768
(CFH) =
C
40 (12) 81 170 320 657
199,000+65,000
50 (15) 72 151 284 583
(CFH) =
1,000
60 (18) 65 137 257 528
70 (21) 60 126 237 486
An
(CFH) =
264
3/hr
80 (24) 56 117 220 452
For this example, the pipe diameter must
be at least 3/4 in. pipe size and 10 ft (3 m)
in length.
90 (27) 52 110 207 424
100 (30) 50 104 195 400
Answer
C
Btu/ft
3
54 Rinnai Tankless Water Heater Installation and Operation Manual
Table 25: Pressure Drop 3.0 in. wc
Example
Rinnai Model Gas Input:
Additional Appliance Total Gas Input:
Heating Value of Gas:
Cubic Feet Per Hour (CFH):
A + B
Intended use: Initial supply
pressure of 8.0 in. wc
or greater.
Schedule 40 Metallic Pipe
Inlet Pressure: Less than 2 psi
Specific Gravity: 0.60
Information in table
obtained from
NFPA 54, ANSI
Z223.1 - 2021.
Nominal Pipe Size (in.)
1/2 3/4 1 1 1/4
Length in ft
(meters)
Capacity in Cubic Feet of Gas per Hour
10 (3) 454 949 1,790 3,670
20 (6) 312 652 1,230 2,520
30 (9) 250 524 986 2,030
(CFH) =
C
40 (12) 214 448 844 1,730
199,000+65,000
50 (15) 190 397 748 1,540 (CFH) =
1,000
60 (18) 172 360 678 1,390
70 (21) 158 331 624 1,280
(CFH) =
264
3/hr
80 (24) 147 308 580 1,190
For this example, the pipe diameter
must be at least 1/2 in. pipe size and
20 ft (6 m) in length.
90 (27) 138 289 544 1,120
100 (30) 131 273 514 1,060
Natural Gas
Propane (Undiluted)
Table 26: Pressure Drop 0.5 in. wc
Information in table obtained from Schedule 40
Metallic Pipe NFPA 54, ANSI Z223.1 - 2021.
Inlet Pressure: 11 in wc
Specific Gravity: 1.50
Nominal Pipe Size (in.)
1/2 3/4 1 1 1/4
Length in ft
(meters)
Capacity in Thousands of Btu per Hour
10 (3) 291 608 1,150 2,350
20 (6) 200 418 787 1,620
30 (9) 160 336 632 1,300
40 (12) 137 287 541 1,110
50 (15) 122 255 480 985
60 (18) 110 231 434 892
70 (21) 101 212 400 821
80 (24) 94 197 372 763
90 (27) 89 185 349 716
100 (30) 84 175 330 677
Answer:
Example
Rinnai Model Gas Input:
Additional Appliance Total Gas Input:
Total gas Input
A
199,000
Btu/hr
For this example, the pipe diameter
must be at least 1/2 in. nominal pipe
size and 10 ft (3 m) in length.
B
65,000
Btu/hr
Total Gas
Input
=
A + B
Total Gas
Input
=
199,000 + 65,000
Answer:
Total Gas
Input
=
264,000
Btu/hr
A
Btu/hr
B
Btu/hr
C
Btu/ft
3
199,000
65,000
1,000
Rinnai Tankless Water Heater Installation and Operation Manual 55
Post-Power Supply Connection Checklist
□
Confirm that the electricity is supplied from 120 VAC, 60 Hz power source and is in a properly
grounded circuit.
□
Confirm that an extension cord or an adapter plug has NOT been used with the water heater.
When connecting the power supply, follow these guidelines:
• Do not rely on the gas or water piping to ground the water heater. Ground locations are provided
inside the water heater.
• The water heater requires 120 VAC, 60 Hz power from a properly grounded circuit.
• If using the 6.5 ft (2.0 m) power cord supplied with the water heater, plug it into a standard 3
prong 120 VAC, 60 Hz properly grounded wall outlet. The supplied power cord is outdoor rated
and can be used outdoor.
• For outdoor installation, a field-supplied disconnect switch may be installed for the incoming 120
VAC power. The switch should be a type that is suitable for outdoor use. Check the National
Electrical Code, ANSI/NFPA 70 and your local codes for a proper switch type to use in your
area. Power connections must be protected from the weather.
• The wiring diagram is located on the inside of the water heater front cover.
WARNING
• Do not use an extension cord or adapter plug with this appliance.
• The water heater must be electrically grounded in accordance with local codes and ordinances
or, in the absence of local codes, in accordance with the National Electrical Code, ANSI/ NFPA
No. 70.
• Indoor water heaters are equipped with a three-prong (grounding) plug for your protection
against shock hazard and should be plugged directly into a properly grounded three-prong
receptacle. Do not cut or remove the grounding terminal from this plug.
56 Rinnai Tankless Water Heater Installation and Operation Manual
This tankless water heater is set up for natural
gas and indoor installations as default. When
power is connected for the first time, you need
to confirm the settings below or change them
properly.
If proper settings are
not selected before you
use the tankless water
heater, it will cause a hazardous situation which
results in personal injury or property damage.
WARNING
Confirm/change initial settings of the tankless
water heater by choosing one of the two options
below:
•
Option 1 (recommended): Confirm/change
settings from a smart device using
Bluetooth Low Energy (BLE).
•
Option 2: Confirm/change settings from the
tankless water heater controller.
3. Open the Rinnai Central app from your
smart device and log into the Rinnai
Central app with a professional account.
4. Push the Bluetooth button on the
controller. The Bluetooth LED light turns
solid.
To confirm/change initial settings of the tankless
water heater from a smart device using BLE
(recommended), follow the steps below:
Note: To utilize BLE, your connecting device
(smartphone, tablet, computer, etc.) needs to
have Bluetooth 4.0 or a newer version. Contact
your connecting device manufacturer if you are
not sure if your connecting device has Bluetooth
4.0 or a newer version.
1. Download the Rinnai Central
app by scanning the following
QR code:
SEt
Figure 50
2. Supply power to the tankless water heater
for the first time. The controller displays
“SEt” and the Priority button LED light on
the controller is blinking.
5. Tap “Connect to a Rinnai Tankless Water
Heater” on the Rinnai Central app. You will
hear a beeping sound when pairing between
the app and water heater is established.
SEt
Figure 51
6. Follow the steps in the Rinnai Central app
to confirm and/or change your tankless
water heater settings.
7. When settings are complete, the controller
display will be blank.
Figure 52
Figure 53
Rinnai Tankless Water Heater Installation and Operation Manual 57
1. Supply power to the tankless water heater
for the first time. The controller displays
“SEt” and the Priority button LED light on
the controller is blinking.
2. Press the “Priority” button. The controller
displays “nG” (natural gas).
4. The controller displays “In” (indoor).
Figure 58
In
SEt
Figure 54
Figure 55
nG
3(A). If using natural gas: Press the “On/Off”
button to confirm natural gas. Then,
proceed to step 4.
If using propane gas, skip this step and
proceed to step 3(B).
Figure 56
nG
3(B). If using propane gas: Press the up or
down arrow button. The controller
displays “LPG” (Liquid Propane Gas).
Press the “On/Off” button to confirm
Liquid Propane Gas. Proceed to step 4.
LPG
5(A). If you install the tankless water heater
indoors: Press the “On/Off” button to confirm
“In” (Indoor). Proceed to step 6.
If you install the tankless water heater
outdoors with the Rinnai outdoor vent cap,
skip this step and proceed to step 5(B).
Figure 59
In
Figure 57
58 Rinnai Tankless Water Heater Installation and Operation Manual
5(B). If you install the tankless water
heater outdoors with the Rinnai
outdoor vent cap: Press the up or
down arrow buttons. The controller
displays “Out” (Outdoor).
Press the “On/Off” button to confirm
“Out” (Outdoor).
Proceed to step 6.
6. The controller displays “nG” or “LPG”,
and “In” or “Out” alternatively while the
“Priority” button is blinking. The controller
shows current gas setting and indoor/
outdoor setting.
For example, the controller displays “NG”
and “In” alternatively, indicating the water
heater is set for natural gas and indoor
installation. If you need to change these
settings, press the up arrow button to go
back to step 1. Otherwise, press the
“Priority” button.
Figure 60
Out
Figure 62
Figure 61
7. The controller briefly displays “888” while
a beeping sound is observed. Then,
complete initial settings and the controller
is off.
888
8. If you set initial settings incorrectly, you
can adjust the settings by configuring the
parameter settings. Follow the steps in
section “4.13 Configure Parameter
Settings” and change parameters 10
(Gas Type) and 14 (Indoor/Outdoor)
correctly.
9. After initial settings are complete, press
the “On/Off” button to turn on the unit.
Figure 63
10. If "LPG" (Liquid Propane Gas) is
selected, apply the supplied gas
conversion label at an open space above
the existing label on the left side of the
water heater.
Note: See the “Gas Conversion Manual”
for specific label location.
11. The default altitude setting for this water
heater is 0-2,000 ft. (0-610 m). If this
water heater is installed at a different
altitude, select the appropriate altitude
setting. Also, set up other parameters
properly. Refer to section "4.13 Configure
Parameter Settings" for specific details
on setting parameters.
Rinnai Tankless Water Heater Installation and Operation Manual 59
Certain elements of the installation may require adjusting the parameters of the tankless water
heater.
To adjust the parameters:
1. Locate the PC Board (lower front of unit).
2. Locate the two push buttons (A and B) on the PC Board.
3. Press the “A” button for 1 second. The controller displays 01A or 01b (Figure 64).
A
………B
4. Use the up and down arrow buttons on the controller to
select a setting number (see Parameter Settings Table on
next page).
5. Once the desired setting number
is selected, use the “On/Off”
button on the controller to
change the selection for the
setting number.
Example: Display will change
from 01A to 01b for Maximum
Temperature setting (as shown
in the images).
6. To exit and save changes, press the
“A” button for 1 second.
WARNING
DO NOT adjust parameter settings unless specifically instructed to do so.
01 A
01 b
Figure 65
Figure 64
Figure 66
01 A
60 Rinnai Tankless Water Heater Installation and Operation Manual
Table 27. Parameter Settings
Setting
#
Setting
Description
Selection
A b C d
0 1
Maximum Set
Temperature
120°F
(49°C)
140°F
(60°C)
0 2
High Altitude
Installation Location
0 - 2,000 ft
(0 - 610 m)
2,001 - 5,400 ft
(610 - 1,646 m)
5,401 - 7,700 ft
(1,646 - 2,347 m)
7,701 - 10,200 ft
(2,347 - 3,109 m)
0 3
Service Soon
1
Disabled 0.5 Year 1 Year 2 Years
0 4
3
Recirculation
Settings
No
Recirculation
Recirculation
(Dedicated)
Recirculation
(Crossover)
0 5
Recirculation Mode
2
* Economy Comfort Commercial
5
0 6
Control Switch BMS
7
Air Handler (AH)
0 7
Units in Standby
(EZConnect™)
2 1
0 8
EZConnect™ Secondary Primary
1 0
Gas Type NG LPG
1 2
Built-in Pump Setting Without Pump With Pump
1 3
Water Heater Model
(Factory set values
and not adjustable)
199 (3237) 180 (2934) 160 (2530) 130 (2024)
1 4
Indoor/Outdoor
Internal
(Indoor)
External
(Outdoor)
1 5
3
Low Activation Mode On Off
1 6
Pump Speed* Max High Medium Low
1 7
4
First Day Pump
Operation*
Pump Off Pump On
1 8
6
Smart-Circ with BLE
Button*
Smart-Circ is
disabled
Smart-Circ is
enabled
* Pump models only.
1
See section “4.13.3 Service Indicator (Service Soon, 55)” for more information.
2
Setting 05 is available only if setting 04 is selected.
Economy mode cycles the pump less often, using less energy to maintain the circulation loop temperature.
Comfort mode cycles the pump more frequently, ensuring the loop temperature remains higher (but also uses
more energy).
3
Low Activation Mode must be in the ON position (15A ) if crossover recirculation is selected (Parameter 04C).
4
For the first 24-hours of operation, Smart-Circ will learn hot water usage patterns and operate pump based on
the learned patterns. On the first day, when the tankless water heater has no learned patterns, the unit can be
set to no pump operation (Pump Off/No Recirc) for the first 24 hours or to the pump operating (Pump On/Recirc)
multiple times per hour depending on setting 05 (Recirculation Mode).
5
Commercial mode should not be used for residential applications. Application of commercial mode may result in
excessive machine wear and energy consumption.
6
To comply with California Title 24, select 18A (Smart-Circ is disabled).
7
BMS = Building Management System
Rinnai Tankless Water Heater Installation and Operation Manual 61
This water heater includes a service indicator (Service Soon, SS). When selected in the parameter
settings, an SS code will display on the controller indicating that it is time to flush and service the
water heater.
• Selection is installer’s preference based on water conditions or other factors that may influence
the suggested interval of service.
• See the “Parameter Settings” section of this manual for selectable service intervals.
• If Service Soon (SS) appears on the controller display, contact your local service provider to flush
and service the water heater (see section “6.3 Flushing the Heat Exchanger”).
• Service Soon will appear again based on the selected service interval.
To reset Service Soon (55)
SS
Figure 67(2)
Service Soon (
55
) will display on the
controller again when the water heater
reaches the interval selected in the
parameter settings.
Press and hold the
"A" button until "SS"
disappears.
55
A
A
B
To perform a combustion analysis:
1. Remove the front panel by removing the two screws
and releasing the two latches.
2. Remove the clamp holding the combustion analysis
port cap.
3. Remove the combustion analysis port cap and insert
the gas analyzer probe into the port.
4. Put the water heater into operation for at least five
minutes. Measure CO2 or O2, as applicable, in the
exhaust system.
If combustions exceed the values below:
• Ensure gas type is correct.
• Check exhaust and inlet air for blockage.
• Please call Rinnai Technical Support.
WARNING
Combustion analysis must be performed by a trained and qualified professional.
Figure 67(1)
Insert gas analyzer probe into combustion
analysis port.
5. After measurement, remove the gas analyzer probe, place the combustion analysis port cap
back on, and reinstall the clamp to secure the cap in place.
CO2 O2
7.0% - 11.0% 1.7% - 8.7% NG
7.9% - 11.9% 2.8% - 8.9% LPG
62 Rinnai Tankless Water Heater Installation and Operation Manual
Rinnai RX Tankless Water Heaters include Circ-Logic technology that offers the comfort and
convenience of instant hot water with the use of an external recirculation pump. Circ-Logic controls
the on/off sequence and operation cycles of the external recirculation pump through the
programming of the tankless water heater’s parameter settings. Smart-Circ™ is the factory default
setting for recirculation. Smart-Circ™ allows the water heater to identify when hot water is used, and
then operates recirculation on subsequent days to reduce wait time for hot water. If a fixed
recirculation schedule is desired, then installation of an MC-195T-US Timer/controller or Wi-Fi
Module is required.
With residential units, the external pump cable is not included with the tankless water heater and
must be purchased separately. Circ-Logic operates in either Economy or Comfort mode based on
the parameter settings of the water heater.
• Economy Mode - Cycles the pump less often, using less energy to maintain the circulation loop
temperature.
• Comfort Mode - Cycles the pump more frequently, ensuring the loop temperature remains higher
(but also uses more energy).
Note: Rinnai offers an Internal Add-on Recirculation Conversion Kit (part number: RX2RXPCK) to
convert a no pump model to a pump model.
Rinnai Set Temperature
140 135 130 125 120 115 110 108 106 104 102 100 98
Typical Pump OFF Intervals (Minutes)
Economy 18 20 22 24 28 32 38 40 44 48 52 56 62
Comfort 9 10 11 12 14 16 19 20 22 24 26 28 31
Table 28
Components
within dashed
line are inside
water heater
External
Pump
FUSE
BL
R
GN
External Pump
Harness:
Rinnai Part #:
105000250
Connect Ground (GN)
Wire to tankless housing
BK
W
Figure 68
Rinnai Tankless Water Heater Installation and Operation Manual 63
Complete the following checklist when water heater installation is complete. You should be able to
answer YES to each question. If you answer NO to any question, installation is not complete. Refer
to the applicable section in the Rinnai Tankless Water Heater Installation and Operation Manual for
additional information.
For assistance, contact your local dealer or distributor, or call Rinnai Customer Care at 1-800-621-
9419.
INSTALLATION LOCATION
YES NO
Have you verified the unit, vent and air intakes meet the clearance requirements?
□ □
COMBUSTION AIR & VENTING
YES NO
Have all corrosive compounds been removed from around the combustion air inlet of
the tankless water heater?
□ □
Have you followed the combustion air requirements to provide sufficient combustion air
for the tankless water heater?
□ □
Are the correct venting products for the installed model being utilized?
□ □
Have you installed the vent screen (s) for PVC vent applications?
□ □
Have you verified the vent system does not exceed maximum length?
□ □
PLUMBING YES NO
Have the water lines been purged of all debris and the filter cleaned?
□ □
Have you verified the hot and cold water lines to the tankless water heater are
not interchanged?
□ □
Does the water supply to the heater have adequate pressure? Is it free of chemicals?
Did you verify it does not exceed total hardness that will damage the heat exchanger?
□ □
Have you verified that no toxic chemicals were introduced to the potable water?
□ □
Did you drain the tankless water heater if not intended to be used immediately?
□ □
Have water quality issues (if any) been addressed?
□ □
Have you performed the leak and pressure test for the tankless water heater and
plumbing system?
□ □
ISOLATION VALVES YES NO
Are isolation valves installed? Isolation valves are not required, but highly recommended.
□ □
PRESSURE RELIEF VALVE (PRV)
YES NO
Does the PRV comply with the standard for Relief Valves for Hot Water Supply
Systems, ANSI Z21.22/CSA 4.4 or the ANSI/ASME Boiler and Pressure Vessel Code
Section IV?
□ □
Did you verify the PRV is rated up to 150 psi and (at least) the maximum Btu/hr of the
tankless water heater?
□ □
Is the discharge from the PRV piped to the ground or into a drain system as per local
codes?
□ □
Is the discharge line from the PRV pitched downward and does it terminate 6 in. (152
mm) above the drains?
□ □
Is the discharge end of the line plain (unthreaded) and a minimum of 3/4 in. diameter?
□ □
Is the discharge line material suitable for at least 180°F (82°C) water?
□ □
Did you take measures to protect the PRV and PRV discharge line from freezing?
□ □
Have you verified the PRV is not plumbed with the condensate drain line?
□ □
Have you verified the PRV is not plugged and that reducing fittings, valves, or other
restrictions are not installed in the relief line?
□ □
1
2
3
4
5
64 Rinnai Tankless Water Heater Installation and Operation Manual
CONDENSATE DRAIN
YES NO
If the condensate pump is installed, is it wired to deactivate the tankless water
heater in the event of failure? For more information, refer to section “4.9.3
Condensate Pump Safety Switch Wiring.”
□ □
Did you verify the condensate drain pipe is as short as possible and has a downward
pitch toward the drain or condensate pump?
□ □
Is all condensate drained and disposed of as per local codes?
□ □
Did you use ONLY corrosion resistant materials for the condensate drain lines?
□ □
Did you verify the condensate drain pipe along its entire length is at least the
same diameter as the drain line (1/2 in. NPT)?
□ □
Did you check to ensure the condensation drain lines are protected from freezing?
□ □
If a floor pump is not available or the drain is above the level of the condensate
drain, did you install a condensate pump?
□ □
Have you verified the condensate drain line is not plumbed with the pressure relief
valve?
□ □
Have you confirmed the condensate drain line is not connected with an air
conditioning evaporator coil drain?
□ □
Have you verified an external condensate trap is not installed? (This tankless water
heater has an integrated condensate trap.)
□ □
Have you confirmed the end of the condensate drain pipe is open to atmosphere?
□ □
GAS SUPPLY YES NO
Did you verify the gas system is appropriately sized?
□ □
Did you verify the water heater is rated for the gas type supplied?
□ □
Have you performed a gas line and connection leak test?
□ □
Did you install a manual gas control valve in the gas line to the water heater?
□ □
Is the inlet gas pressure within limits?
□ □
Did you purge the gas line of any air or debris before connecting the water heater?
□ □
If "LPG" (Liquid Propane Gas) is selected, apply the supplied gas conversion label at
an open space above the existing label on the side of the water heater.
□ □
RECIRCULATION PUMP RXP Series Models Only (RXP199i and RXP160i) YES NO
Have parameter settings for recirculation been properly set?
□ □
Is the recirculation pipe length less than the maximum allowed length?
□ □
Did you drain the tankless water heater if not intended to be used immediately?
□ □
Have you performed a leak and pressure test on the thermal bypass valve installation?
□ □
(Crossover Mode Only) Was the thermal bypass valve installed at the furthest fixture
from the water heater?
□ □
6
7
8
Rinnai Tankless Water Heater Installation and Operation Manual 65
Topics in this section
• Safety Precautions
• Gas Operating Instructions
• Control Panel
• Setting the Temperature
• Performance Data
• Diagnostic Codes
• Configuring Recirculation (If Applicable)
•
Do not store or use gasoline or
other flammable vapors and liquids
in the vicinity of this or any other
appliance.
•
BEFORE OPERATING, smell all
around the appliance area for gas.
Be sure to smell next to the floor
because some gas is heavier than
air and will settle on the floor.
•
WHAT TO DO IF YOU SMELL
GAS
−
Do not try to light any appliance.
−
Do not touch any electrical
switch; do not use any phone in
your building.
−
Immediately call your gas
supplier from a neighbor’s
phone. Follow the gas supplier’s
instructions.
−
If you cannot reach your gas
supplier, call the fire
department.
•
Installation and service must be
performed by a trained and
qualified professional, service
agency or the gas supplier.
WARNING
If the information in these
instructions is not followed
exactly, a fire or explosion may
result causing property damage,
personal injury, or death.
• Ne pas entreposer ni utiliser
d’essence ou ni d’autres vapeurs
ou liquides inflammables à
proximité de cet appareil ou de
tout autre appareil.
•
AVANT D’OPÉRER, sentir le gaz
autour de la zone de l’appareil.
Assurez-vous de sentir à côté du
sol car certains gaz sont plus
lourds que l’air et se déposeront
sur le sol.
• QUE FAIRE SI VOUS SENTEZ
UNE ODEUR DE GAZ :
− Ne pas tenter d’allumer
d’appareil.
− Ne touchez à aucun
interrupteur ; ne pas vous
servir des téléphones se
trouvant dans le bâtiment.
− Appelez immédiatement votre
fournisseur de gaz depuis un
voisin. Suivez les instructions
du fournisseur.
− Si vous ne pouvez rejoindre le
fournisseur, appelez le
service des incendies.
• L’installation et l’entretien doivent
être assurés par un installateur
ou un service d’entretien qualifié
ou par le fournisseur de gaz.
AVERTISSEMENT
Assurezvous de bien suivre les
instructions données dans cette
notice pour réduire au minimum le
risque d’incendie ou d’explosion
ou pour éviter tout dommage
matériel, toute blessure ou la mort.
66 Rinnai Tankless Water Heater Installation and Operation Manual
•
Keep the area around the appliance clear
and free from combustible materials,
gasoline, and other flammable vapors
and liquids.
•
Do not use this appliance if any part has
been under water. Immediately call a
trained and qualified professional to
inspect the appliance and to replace any
part of the control system and any gas
control which has been under water
(N’utilisez pas cet appareil s’il a été
plongé dans l’eau, même partiellement.
Faites inspecter l’appareil par un licence
professionnelle et remplacez toute partie
du système de contrôle et toute
commande qui ont été plongés dans
l’eau.)
•
Should overheating occur or the gas
supply fail to shut off, turn off the manual
gas control valve to the appliance
(En cas de surchauffe ou si l’alimentation
en gaz ne s’arrête pas, fermez
manuellement le robinet d’arrêt de
l’admission de gaz.)
•
Use only your hand to push in or turn the
gas control knob. Never use tools. If the
knob will not push in or turn by hand, do
not try to repair it, call a trained and
qualified professional. Force or attempted
repair may result in a fire or explosion.
•
This appliance does not have a pilot. It is
equipped with an ignition device which
automatically lights the burner. DO NOT
try to light the burner by hand.
•
DO NOT use an extension cord or an
adapter plug with this appliance.
•
Any alteration to the appliance or its
controls can be dangerous and will void
the warranty.
•
If you install this water heater in an area
that is known to have hard water or that
causes scale build-up the water must be
treated and/or the heat exchanger
flushed regularly. Rinnai offers a “Scale
Control System” that provides superior
lime scale prevention and corrosion
control by feeding a blend of control
compounds into the water supply.
Damage and repair due to corrosive
compounds in the air is not covered by
warranty.
•
Keep the combustion air vent pipe
location free of chemicals, such as
chlorine or bleach, that produce fumes.
These fumes can damage components
and reduce the life of your appliance.
Damage and repair due to scale in the
heat exchanger is not covered by
warranty.
•
Always check the water temperature
before entering a shower or bath.
•
Do not adjust the parameter settings
unless you are trained on Rinnai tankless
water heaters, or specifically instructed
to do so.
Rinnai Tankless Water Heater Installation and Operation Manual 67
WARNING
A. This appliance does not have a pilot. It is
equipped with an ignition device which
automatically lights the burner. Do not try to
light the burner by hand.
B. BEFORE OPERATING, smell all around the
appliance area for gas. Be sure to smell next
to the floor because some gas is heavier
than air and will settle on the floor.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electric switch; do not
use any phone in your building.
• Immediately call your gas supplier from a
neighbor’s phone. Follow the gas
supplier’s instructions.
• If you cannot reach your gas supplier,
call the fire department.
C. Use only your hand to push in or turn the gas
control valve. Never use tools. If the gas
control valve will not turn by hand, do not try
to repair it, call a qualified service technician.
Force or attempted repair may result in a fire
or explosion.
D. Do not use this appliance if any part has
been under water. Immediately call a
qualified service technician to inspect the
appliance and to replace any part of the
control system and any gas control which
has been under water.
If you do not follow these instructions exactly, a fire or explosion may result
causing property damage, personal injury or loss of life.
1. Set the temperature controller to lowest
setting.
2. Turn off all electric power to the appliance if
service is to be performed.
3. Turn the manual gas control valve located at
gas inlet of appliance clockwise to the OFF
position.
TURN OFF GAS TO APPLIANCE
1. STOP! Read the safety information above.
2. Set the temperature controller to lowest
setting.
3. Turn off all electric power to the appliance.
4. This appliance does not have a pilot. It is
equipped with an ignition device which
automatically lights the burner. Do not try to
light the burner by hand.
5. Turn the manual gas control valve located at
gas inlet of appliance clockwise to the OFF
position.
6. Wait five (5) minutes to clear out any gas.
Then smell for gas, including near the floor. If
you smell gas, STOP! Follow “B” in the safety
information above. If you don’t smell gas, go
to the next step.
7. Turn the manual gas valve located at gas inlet
of appliance counterclockwise to the full ON
position.
8. Turn on all electric power to the appliance.
9. Set the temperature controller to desired
setting.
10.If the appliance will not operate, follow the
instructions “To Turn Off Gas To Appliance”
and call your service technician or gas
supplier.
OPERATING INSTRUCTIONS
FOR YOUR SAFETY READ BEFORE OPERATING
68 Rinnai Tankless Water Heater Installation and Operation Manual
The controller panel allows you to adjust the
water temperature, lock the controller on a set
temperature, and view diagnostic information.
To unlock the controller, follow the above steps.
1. To lock the integrated controller, press and
hold down the “Priority” button (Figure 71).
2. While holding down the “Priority” button,
press the up arrow button (Figure 71) until
a beep is heard (approximately 5
seconds). Then, release both buttons at
the same time.
3. A key illuminates when the controller is
locked.
To eliminate the beeps when keys are pressed,
press and hold both the up and down arrow
buttons (Figure 70) at the same time until a
beep is heard (approximately 3 seconds).
Then, release both buttons.
To turn on the beeps, repeat the above steps.
“In Use” light. Indicates the water
heater is in use
Indicates the controller is locked
Allows Bluetooth pairing for setup
“Priority” button. Enables controller
when multiple controllers are used
Display
Increases hot water temperature
Turns the water heater on or off
Decreases hot water temperature
The integrated controller “In Use” light flashes
based on the operation status of the water
heater and integrated pump.
NOTE
For outdoor installations, the controller is
automatically locked after 30 minutes inactivity.
Indicates ignition
and water flow.
Indicates ignition and
pump operation.
Indicates pump operation
with no ignition.
Solid Light
Slow Flash
Rapid Flash
Figure 72
Figure 71
Figure 70
Figure 69
Table 29
7
6
5
4
3
2
1
8
1
2
3
4
5
6
7
8
Rinnai Tankless Water Heater Installation and Operation Manual 69
This water heater requires a minimum flow
rate to operate. This rate can be found on
the specification page in this manual. In
some cases when you are not getting hot
water or if the water alternates between hot
and cold, it is due to the water flow being
below or close to the minimum flow rate.
Increasing the flow rate should resolve these
problems in these cases.
If you are experiencing issues with higher
temperature settings, then reduce the
temperature setting. Selecting a temperature
closer to that which is actually used at the
faucet will increase the amount of hot water
being delivered to the faucet, due to less
cold water mixing at the fixture
Water temperatures over 125°F (52°C) can
cause severe burns or scalding resulting in
death.
Hot water can cause first degree burns with
exposure for as little as:
•
3 seconds at 140°F (60°C)
•
20 seconds at 130°F (54°C)
•
8 minutes at 120°F (49°C)
Children, disabled, or elderly are at highest
risk of being scalded.
Feel water before bathing or showering.
DANGER
IMPORTANT
•
While any hot water is being provided,
the temperature setting can only be
adjusted between 98°F and 110°F
(37°C and 43°C).
•
Check local codes for the maximum
water temperature setting allowed when
used in nursing homes, schools, day
care centers, and all other public
applications.
•
If a newly installed water heater with a
controller has not been powered for at
least 6 hours then the temperature will
return to the default setting of 104°F (40°
C) if power is interrupted.
•
There may be a variation between the
temperature displayed on the
temperature controller and the
temperature at the tap due to weather
conditions or the length of pipe to the
water heater.
1. If the water heater is off, press the “On/Off”
button to turn on.
2. The “Priority” button enables a controller if
multiple controllers are being used. If the
“Priority” light is off, then press the “Priority”
button on the temperature controller. The
“Priority” light will glow indicating that this
controller is controlling the temperature and
that the water heater is ready to supply hot
water. The priority can only be changed while
no hot water is running.
3. Press the up or down arrow buttons to obtain
the desired temperature setting (Figure 73).
All hot water sources are able to provide
water at this temperature setting until it is
changed again at this or another temperature
controller.
Figure 73
70 Rinnai Tankless Water Heater Installation and Operation Manual
Table 30: Temperature Settings
1. Press and hold the down arrow button.
2. While holding the down arrow button for 2
seconds, press and hold the “On/Off” button (hold
both buttons simultaneously) until “01” appears.
* These models have a default maximum temperature of 120°F (49°C) and an option to increase the
maximum temperature to 140°F (60°C). Refer to section “4.13 Configure Parameter Settings” for
further details.
†For Crossover Mode, minimum temperature setting is 120°F (49°C).
The water heater can deliver water at only one temperature setting at a time. The available
temperatures are provided below. A temperature lower than 98°F (37°C) can be obtained at the tap
by mixing with cold water.
To change the temperature scale from Celsius to Fahrenheit or vice versa, press and hold the “On/
Off” button on the controller for 5 seconds while the water heater is OFF.
3. Use the up and down arrow buttons to scroll to the
desired information described in the “Performance
Data Table” on the next page.
4. To exit performance data, repeat step 2 above.
5. When complete, the set temperature appears in the
display.
Figure 76
Figure 75
Figure 74
Temperature Settings
Fahrenheit (°F) 98 100 102 104 106 108 110 115 120† 125* 130* 135* 140*
Celsius (°C) 37 38 39 40 41 42 43 46 49 52 54 57 60
Rinnai Tankless Water Heater Installation and Operation Manual 71
Table 31. Performance Data Table
* Refer to the following tables for additional information:
# Data Unit
0 1
Water Flow Rate x0.1 gal/min
02
Outgoing Temperature °F
03
Combustion Hours x100 Hours
04
Combustion Cycles *
05
Fan Frequency Hz
06
Additional Controllers Connected *
07
Water Flow Control Position 0=Mid 1=Open 2=Closed
08
Inlet Temperature °F
09
Fan Current x10 mA
10
Total Bath Fill Amount Gallons
1 1
HEX Outlet Temp. °F
12
Bypass Flow Control Position Degrees of opening
17
Freeze Protection Temperature °F
19
Pump Hours x100 Hours
20
Pump Cycles *
2 1
Exhaust Temperature °F
22
Pump Frequency Hz
23
Lime Detecting Temperature °F
24
Descaling Cycles
DISPLAY CYCLE COUNT
000 to 999
x100 (0 to 99,900)
10– to 99-
x10,000 (100,000 to 990,000)
1-- to 6--
x1,000,000 (1,000,000 to 6,000,000)
CONTROLLER MODEL CONNECTED NOT CONNECTED
MC
__1 __0
BC
_1_ _0_
BSC & BSC2
1__, 2__ (QTY2) 0__
Default display is 100.
_ depends on connection status of another controller.
06
Controllers Connected
04
Combustion Cycles
20
Pump Cycles
72 Rinnai Tankless Water Heater Installation and Operation Manual
* See “Electrical Diagnostics” on Technical Data
Sheet located on inside front cover of water heater.
03
Power interruption during bath fill
(Water will not flow when power
returns)
• Turn off all hot water taps. Press
ON/ OFF twice.
1 0
Air Supply or Exhaust Blockage/
Condensate Trap is Full
• Ensure condensate line is not
blocked.
• Ensure internal air filter is clean with
no obstructions.
• Ensure High Altitude setting. (See
Parameter Settings)
• Ensure combustion air and exhaust
vents are not blocked and approved
venting materials are being used.
• Ensure vent length is within limits.
• Check fan for debris and ensure
wheel turns freely.
• Verify check valve is not stuck
between fan casing and burner
body.
1 1
No Ignition (Heater Not Turning On)
• Check that the gas is turned on at
the water heater, meter, or cylinder.
• Ensure gas line, meter, and/or
regulator is sized properly.
• If the system is propane, make sure
that gas is in the tank and the tank
is properly purged.
• Ensure gas type and inlet gas
pressure are correct.
• Bleed all air from gas lines.
• Check the ground wire for the PC
Board.
• Ensure flame rod wire is connected.
• Ensure igniter is operational.*
• Check gas solenoid valves for open
or short circuits.*
• Verify selected gas type is correct.
• Ensure condensate line is not
blocked.
To display diagnostic codes:
Turn off the water heater by pressing the “On/Off” button.
Press and hold the “On/Off” button for 2 seconds and then the up
arrow button simultaneously.
The last nine maintenance codes display and flash one after the
other.
To exit diagnostic codes and return the water heater to normal
operation, press and hold the “On/Off” button for 2 seconds and then
the up arrow button simultaneously.
Turn on the water heater by pressing the “On/Off” button.
Figure 77
Some of the checks below should be performed by a trained and qualified
professional. Consumers should never attempt any action that they are not
qualified to perform.
WARNING
1 2
No Flame
• Check that the gas is turned on at
the water heater, gas meter, or
cylinder.
• Ensure gas line, meter, and/or
regulator is sized properly.
• If the system is propane, make sure
that gas is in the tank.
• Ensure flame rod wire is connected.
• Ensure gas type and inlet gas
pressure is correct.
• Bleed all air from gas lines.
1 4
Heat Exchanger Overheat
• Measure resistance or voltage of
Overheat Switch.*
• Ensure it is not in forced Hi setting.
• Check heat exchanger surface for
hot spots which may be caused by
scale build-up. Refer to instructions
in manual for flushing heat
exchanger. Hard water must be
treated to prevent scale build up or
damage to the heat exchanger.
Rinnai Tankless Water Heater Installation and Operation Manual 73
15
Venturi Control
• Ensure the Venturi motor is
operating correctly.*
• Replace gas valve assembly.
• Clear diagnostic code by resetting
the main power supply to the water
heater.
16
High Outgoing Temperature
(Safety shutdown because water
heater is too hot)
• Confirm fan motor is functioning
correctly.
• Replace the gas valve assembly.
17
Venturi Blockage
• First, follow the recommended
solutions for Diagnostic Code 10.
• If the Code 10 solutions do not
correct the problem, ensure the
Venturi is not blocked.
• Check vent pipes are installed
properly.
• Please call Rinnai Technical
Support to reset the code, or refer
to the Technical Data Sheet located
on the inside of the water heater
front panel.
18
Gas Valve Adjustment Limit
• Ensure gas type is correct.
• Ensure gas type parameter is
correct.
• Please call Rinnai Technical
Support.
19
Electrical Grounding
• Check all components for electrical
short.
21
Data Transfer Error
• If the PCB has been replaced,
ensure the data transfer process
has been completed.
22
Gas Valve Adjustment
• Ensure a Reed switch is located
properly.
• Ensure the gas valve adjustment is
operating correctly.*
25
Condensate Pump (Accessory)
• Confirm wire connections and
harness are good.
• Ensure condensate reservoir is
empty and condensate pump is
operating.
32
Outgoing Thermistor
• Check sensor wiring for damage.
• Measure resistance or voltage of
sensor.*
• Clean sensor of scale build-up.
• Replace sensor.
33
Heat Exchanger Thermistor
• Follow the steps above for Code 32
for troubleshooting
* See “Electrical Diagnostics” on Technical Data Sheet
located on inside front cover of water heater.
34
Lime Detecting Thermistor
• Check sensor wiring for damage.
• Measure resistance or voltage of
sensor.*
• Clean sensor of scale build-up.
• Replace sensor.
38
Exhaust Thermistor
• Check sensor wiring for damage.
• Measure resistance or voltage of
sensor.*
• Replace sensor.
41
Freeze Protection Thermistor
• Follow the steps above for Code 38 for
troubleshooting.
51
Inlet Thermistor
• Check sensor wiring for damage.
• Measure resistance or voltage of
sensor.*
• Clean sensor of scale build-up.
• Replace sensor.
52
Gas Valve
• Check flame rod and wire for damage.
• Check gas solenoid valve for open or
short circuit.*
• Replace gas valve assembly.
• Please call Rinnai Technical Support.
54
High Exhaust Gas Temperature
• Ensure Heat Exchanger fins are clean
and not blocked.
• Check heat exchanger surface for hot
spots which may be caused by scale
build-up. Refer to instructions in
manual for flushing heat exchanger.
Hard water must be treated to prevent
scale build up or damage to the heat
exchanger.
• Confirm inlet water temperature is not
too high.
• Clear diagnostic code by resetting the
main power supply to the water heater.
• Ensure condensate is not blocked.
61
Combustion Fan
• Check the motor wire harness for
loose or damaged connections.
• Measure resistance or voltage of
motor wire harness.*
• Ensure the combustion fan spins
freely.
63
Recirculation Low Flow
• Ensure parameter settings are
correctly set for recirculation mode.
•
Ensure a recirculation loop does not
exceed maximum length. Refer to
Tables 34 or 37.
• Ensure the inlet water filter is clean
and free of debris.
• Ensure Pump supply voltage.
• Ensure air is removed from the
recirculation line.
74 Rinnai Tankless Water Heater Installation and Operation Manual
Visit rinnaipro.myabsorb.com for additional
troubleshooting resources.
65
Water Flow Control
• Measure resistance or voltage
values of the water flow control.*
• The water flow control valve has
failed to close during the bath fill
function. Immediately turn off the
water and discontinue the bath fill
function. Contact a trained and
qualified professional to service the
appliance.
66
Bypass Servo
• Measure the resistance values and
voltage of the bypass servo valve.*
• Ensure the harness and connector
are not wet.
• If the voltage from the PC Board is
abnormal, replace the PC board;
otherwise replace the bypass servo
valve.
70
PC Board
• Replace PC Board
71
Solenoid Valve Circuit
• Ensure dip switch on PC board is in
the OFF position.
• Ensure gas control wire is not loose
or damaged.
• Ensure heater circuit is not
grounded.
• Replace PC Board.
• Check flame rod and wire for
damage.
• Verify HEX is not leaking.
• Please call Rinnai Technical
Support.
72
Flame Rod
• Check flame rod and wire for
damage.
• Verify HEX is not leaking.
• Please call Rinnai Technical
Support.
LC
Scale Build-up in Heat Exchanger
(when checking maintenance code
history, “00” is substituted for “LC”)
• LC indicates that there is scale build
up in the heat exchanger and that
the heat exchanger needs to be
flushed to prevent damage. Refer to
section “6.3 Flushing the Heat
Exchanger” for more information.
Hard water must be treated to
prevent scale build up or damage to
the heat exchanger.
• After flushing, reset LC code as
instructed.
• Please call Rinnai technical
department.
• To reset the LC code temporarily,
push the “On/Off” button on the
temperature controller five times in
five seconds.
FF
Maintenance Indicator
• Placeholder in Diagnostic code
history indicating that a service
provider performed maintenance or
service.
• Enter this code after performing
service by pressing the up and
down arrow buttons and On/Off
simultaneously.
• FF is visible on the monitor.
SS (SS) Service Soon
• SS is a time-based service indicator
set during installation. See section
“4.13 Configure Parameter
Settings” for additional details on
setting and changing the SS
indicator.
• SS indicates that it is time for
service.
• To reset the SS code, press and
hold the "A" button until SS
disappears.
NO CODE - Nothing happens when
water flow is activated
• Verify you have at least the
minimum flow rate required to fire
unit.
• Measure the resistance or voltage
of the water flow control sensor.*
• Clean inlet water supply filter.
• On new installations ensure hot and
cold water lines are not reversed.
* See “Electrical Diagnostics” on Technical
Data Sheet located on inside front cover of
water heater.
FF
Figure 78
Rinnai Tankless Water Heater Installation and Operation Manual 75
This section applies to RXP models only.
Smart-Circ™ is the factory default setting for recirculation. Smart-Circ™ allows the water heater to
identify when hot water is used, and then operates recirculation on subsequent days to reduce wait
time for hot water. If a fixed recirculation schedule is desired, then installation of an MC-195T-US
Timer/controller or Wi-Fi Module is required.
Figure 80
Fixed schedule recirculation for RXP models requires the installation of the Wi-Fi Module or MC-
195T-US controller.
1
If the Wi-Fi Module or MC-195T-US controller is not installed, temporary pump operation can be
initiated by resetting power to the appliance (see section "3.6 Accessories" for part numbers). Visit
rinnai.us/wifi for more information.
Note: Recirculation parameter setting
04
must be set to your circulation mode. See section “4.13
Configure Parameter Settings” for more information.
1
DO NOT install the Wi-Fi Module and MC-195T-US together as they are NOT compatible
accessories.
To remove air, drain the water during pump operation. If the air is not fully removed, the pump could
run dry.
A thermal bypass valve can be installed with water heaters to operate recirculation without a
dedicated return line. The thermal bypass valve should be installed between the hot and cold line at
the farthest fixture in the plumbing system. Refer to section “5.7.2 Recirculation (Crossover Mode)”
for additional details.
NOTE: Thermal bypass valve should only be used for Crossover Mode Recirculation systems.
Fixed recirculation schedule requires the installation of one of the following controllers to set time
intervals and duration of recirculation system operation. Smart-Circ™ is automatically disabled if
a scheduling controller (MC195T-US/ Wi-Fi Module) is installed.
MC-195T-US Timer/Controller
Wired in digital control with integrated
timer function for recirculation control.
Wi-Fi Module
Wired in digital control with integrated
timer function for recirculation control.
Figure 81
Figure 79
Rinnai offers the thermal bypass
valve. Refer to section “3.6
Accessories” for additional details.
76 Rinnai Tankless Water Heater Installation and Operation Manual
1 2
Built-in Pump Setting
•
Non-pump models should always have
1 2 A
without pump setting. Pump models have
1 2 b
with pump setting as default.
1 6
Pump Speed
•
Higher pump speeds during recirculation runs will produce higher noise levels. If the noise
level of the recirculation pump is high, changing parameter setting to
1 6 b , 16C
or
1 6 d
may reduce the noise level of the pump. This, however, will increase the duration of the
recirculation run.
1 7
First Day Pump Operation
•
For the first 24-hours of operation, Smart-Circ will learn hot water usage patterns and
operate the pump based on the learned patterns. On the first day, when the tankless water
heater has no learned patterns, the unit can be set to no pump operation (Pump Off/No
Recirc) for the first 24 hours per Smart-Circ or to the pump operating (Pump On/Recirc)
multiple times per hour depending on parameter setting
05
.
1 8
Smart-Circ with BLE Push Button
•
Default setting is
18A
. With
18A
, Smart-Circ is disabled when a BLE push button is
installed. With
18b
, Smart-Circ and a BLE push button work together.
•
Up to five BLE push buttons can be installed. Refer to section “7.7 Bluetooth Low Energy
(BLE) and App Instructions” on how to install the BLE push button.
NOTICE: California Title 24 does not allow timer-based recirculation system. It requires
demand-based recirculation system. To comply with California Title 24, you should select 18A
setting, and install a BLE push button.
Setting #
Setting
Description
Selection
A b C d
12
Built-in Pump Setting
Without
Pump
With
Pump
16
Pump Speed Maximum High Medium Low
17
First Day Pump
Operation
Pump Off Pump On
18
Smart-Circ with BLE
Push Button
Smart-Circ is
disabled
Smart-Circ is
enabled
Parameter Settings
Refer to section “4.13 Configure Parameter Settings” for instructions on how to access and change
parameter settings.
Table 32
Rinnai Tankless Water Heater Installation and Operation Manual 77
Figure 82
General Guidelines:
•
For the licensed installer / professional
•
For installation in commercial and residential domestic hot water applications only.
•
Rinnai strongly recommends installing insulation to the hot water and dedicated return lines to
decrease the amount of heat loss.
•
DO NOT install in combination with hydronic heating applications.
•
DO NOT electronically manifold (EZConnect™) multiple RXP units together.
•
DO NOT install the MC-195T-US Timer/Controller and Wi-Fi Module together as they are not
compatible accessories.
Two recirculation modes are available:
Dedicated mode (factory default) -
Home includes a dedicated circulation
return line in the plumbing system. The
water heater is shipped configured for
the Dedicated Recirculation Line mode.
Crossover mode - Home does not include a
dedicated circulation return line. Requires
installation of a thermal bypass valve
(included with purchase for RXP models) at
the farthest fixture in the plumbing system.
CROSSOVER MODE
DEDICATED MODE
Hot Water
Cold Water
Connection
Diagram:
Pressure
Relief Valve
Hot Water Drain Valve
Hot Water
Outlet
Figure 83
Condensate
Drain Trap Plug
Water
Drain Plug
Cold Water Inlet
With Filter
Gas Connection
Cold Water
Drain Valve
Condensate
Drain Line
78 Rinnai Tankless Water Heater Installation and Operation Manual
CROSSOVER MODE
Plumbing Diagram (Crossover Mode)
Install thermal bypass valve
at the farthest fixture from the
tankless water heater.
Condensate Drain Line
Floor Drain
Cold Water Supply Line
Gas Supply Line
Hot Water Fixtures
Hot Water Supply Line
Figure 84
Figure 85
Note: Warm water may come out of the
cold side of the faucet for a few seconds.
Rinnai Tankless Water Heater Installation and Operation Manual 79
Parameter Settings
Refer to section “4.13 Configure Parameter Settings” for instructions on how to access and change
parameter settings.
Table 34: Maximum Pipe Length*
(Maximum pipe length includes the hot water supply line and dedicated return line.)
Pipe Diameter 3/4 in. 1/2 in.
Total 400 ft. (122 m) 100 ft. (30 m)
05
Recirculation Modes
•
Economy (Factory Default): Adjust parameter setting to 05A for Economy mode. This mode
cycles the pump less often, using less energy to maintain the circulation loop temperature.
•
Comfort: Adjust parameter setting to 05b for Comfort mode. This mode cycles the pump more
frequently, ensuring the loop temperature remains higher (but also uses more energy).
•
Commercial: Adjust parameter setting to 05C for Commercial mode. This mode cycles the pump
on and off continuously, which may result in excessive machine wear and energy consumption.
Setting #
Setting
Description
Selection
A b C d
04
Recirculation Settings
No
Recirculation
Recirculation
(Dedicated)
Recirculation
(Crossover)
05
Recirculation Mode Economy Comfort Commercial
04
Recirculation Settings
Crossover Mode: Adjust parameter setting to 04c for crossover recirculation applications. Maximum
recirculation loop length of 400 ft (122m) with 3/4 in. pipe or 100 ft (30m) with 1/2 in. pipe
*Take equivalent elbow lengths and all fittings into consideration when calculating pipe length.
Note: If your recirculation loop length exceeds the length listed in the above table, the recirculation
loop may not provide proper heat to all fixtures.
Pump Status Typical Intervals
Economy 10
Off
Comfort 4
Commercial 4
The internal pump in an RXP model runs
based on time intervals only and not
water temperature (like dedicated return
line recirculation systems).
IMPORTANT
Table 33
Table 35
80 Rinnai Tankless Water Heater Installation and Operation Manual
Condensate Drain Line
Floor Drain
Cold Water Supply Line
Gas Supply Line
Hot Water Fixtures
Hot Water Supply Line
Locate Drain
Valve as close
as possible to
the Cold Water
Supply Tee
Dedicated Recirculation Line
Plumbing Diagram
(Dedicated Mode)
Figure 87
Figure 86
DEDICATED MODE
Rinnai Tankless Water Heater Installation and Operation Manual 81
Parameter Settings
Refer to the parameter setting section of this manual for instructions on how to access and change
parameter settings.
Table 37: Maximum Pipe Length*
(Maximum pipe length includes the hot water supply line and dedicated return line.)
Pipe Diameter 3/4 in. 1/2 in.
Total 400 ft. (122 m) 100 ft. (30 m)
05
Recirculation Modes
•
Economy (Factory Default): Adjust parameter setting to 05A for Economy mode. This mode
cycles the pump less often, using less energy to maintain the circulation loop temperature.
•
Comfort: Adjust parameter setting to 05b for Comfort mode. This mode cycles the pump more
frequently, ensuring the loop temperature remains higher (but also uses more energy).
•
Commercial: Adjust parameter setting to 05C for Commercial mode. This mode cycles the pump
on and off continuously, which may result in excessive machine wear and energy consumption.
Setting #
Setting
Description
Selection
A b C d
04
Recirculation Settings
No
Recirculation
Recirculation
(Dedicated)
Recirculation
(Crossover)
05
Recirculation Mode Economy Comfort
Commercial
Setting
04
Recirculation Settings
Dedicate Mode: Adjust parameter setting to 04b for dedicated recirculation applications. Maximum
recirculation loop length of 400 ft (122m) with 3/4 in. pipe or 100 ft (30m) with 1/2 in. pipe.
*Take equivalent elbow lengths and all fittings into consideration when calculating pipe length.
Note: If your recirculation loop length exceeds the length listed in the above table, the recirculation
loop may not be heated up properly.
Rinnai Set Temperature
140 135 130 125 120 115 110 108 106 104 102 100 98
Typical Pump OFF Intervals (Minutes)
Economy 18 20 22 24 28 32 38 40 44 48 52 56 62
Comfort 9 10 11 12 14 16 19 20 22 24 26 28 31
Table 38
Table 36
82 Rinnai Tankless Water Heater Installation and Operation Manual
This water heater must be inspected
annually by a trained and qualified
professional. Repairs and maintenance
shall be performed by a trained and
qualified professional. The trained and
qualified professional must verify proper
operation after servicing.
Topics in this section
To protect yourself from harm, before
performing maintenance:
•
Turn off the electrical power supply by
unplugging the power cord or by turning
off the electricity at the circuit breaker.
(The temperature controller does not
control the electrical power.)
•
Turn off the gas at the manual gas
control valve, usually located
immediately below the water heater.
•
Turn off the incoming water supply. This
can be done at the isolation valve
immediately below the water heater or by
turning off the water supply to the
building.
WARNING
Keep the appliance area clear and free
from combustible materials, gasoline, and
other flammable vapors and liquids.
WARNING
The following maintenance items are required for
the proper operation of your water heater.
CLEANING
It is imperative that control compartments,
burners, condensate collection and disposal
system, vent screens and circulating air
passageways of the appliance be kept clean.
BURNER
Check burner flame for proper color. Once
ignited, the flame must cover the surface of the
burner. The flame must burn with a clear, blue,
stable flame (refer to “Visual Inspection of Flame”
section on next page). If the flame does not have
this appearance, complete the following steps:
1. Turn off and disconnect electrical power.
Allow to cool. Shut off gas supply.
2. Remove the front panel by removing the two
screws and releasing two latches.
3. Remove the blower assembly and the gas
valve assembly by removing three screws on
the front of the burner assembly, and one
screw on the gas piping at the bottom of the
gas valve assembly.
4. Use a vacuum to remove dust from the main
burner and fan blades. Back of the main
burner can be accessed from the opening of
burner assembly, and the fan blades can be
accessed from the opening of the blower
assembly. Do not use a wet cloth or spray
cleaners on the burner. Do not use volatile
substances such as benzene and thinners as
they may ignite or fade the paint.
5. Inspect O-rings and gaskets prior to
reassembly (replace if damaged).
6. Install and secure the blower assembly and
gas valve assembly by the four screws, and
install and secure the front panel by the two
screws and two latches.
CONDENSATE COLLECTION AND DISPOSAL
SYSTEM
Periodic inspection and cleaning of the
condensate collection and disposal system.
Ensure condensate is flowing and the end of the
drain is open to the atmosphere.
VENT SYSTEM
Periodic cleaning and inspection of the vent
system including screens in the vent termination.
The vent system should be inspected for
blockages including snow or other debris or
damage. If the vent is blocked and cannot be
easily cleared, contact a trained and qualified
professional.
•
Maintenance
•
Cleaning and Inspecting the Air Filter
•
Flushing the Heat Exchanger
•
Draining the Water Heater
Rinnai Tankless Water Heater Installation and Operation Manual 83
PRESSURE RELIEF VALVE
Operate the pressure relief valve manually
once a year. In doing so, it will be necessary to
take precautions with regard to the discharge
of potentially scalding hot water under
pressure. Ensure discharge has a safe place to
flow. Contact with your body or other property
may cause damage or harm.
MOTORS
Motors are permanently lubricated and do not
need periodic lubrication. However you must
keep fan and motor free of dust and dirt by
cleaning annually.
TEMPERATURE CONTROLLER
Use a soft damp cloth to clean the temperature
controller. Do not use solvents.
LIME/SCALE BUILD-UP
Scale build-up is caused by hard water and can
be accelerated if the water heater is set at a
high temperature. Refer to section “6.3 Flushing
the Heat Exchanger” for more information. Refer
to section “Water Quality Guidelines” to
determine if your water needs to be treated or
conditioned. The water must be potable, free of
corrosive chemicals, sand, dirt, or other
contaminates. It is up to the installer to ensure
the water does not contain corrosive chemicals,
or elements that can affect or damage the heat
exchanger. Water that contains chemicals
exceeding the levels required affect and
damage the heat exchanger. Replacement of
the heat exchanger due to water quality damage
is not covered by the warranty.
SNOW ACCUMULATION
Keep the area around flue terminal free of snow
and ice. The water heater will not function
properly if the combustion air or exhaust vent
pipes are impeded (blocked or partially blocked)
by obstructions.
Keep the condensate drain line free of snow
and ice. Ensure the line is not blocked or
clogged and that condensate is flowing freely.
COASTAL INSTALLATIONS
Installations located in or near coastal areas
may require additional maintenance due to
corrosive airborne ocean salt. If corrosion is
observed on the body of the water heater, the
water heater shall be inspected to ensure
proper operation and if necessary, repaired or
replaced.
FILTERS
•
Water Filter — Clean the inlet water filter
by closing the cold and hot water inlet
isolation (shut-off) valves. Put a bucket
under the filter at the bottom of the water
heater to catch any water that is contained
inside the unit. Unscrew the water filter.
Rinse the filter to remove any debris. Install
the filter and open the isolation valves.
•
Air Filter — See section “6.2 Cleaning and
Inspecting the Air Filter” for more
information.
VISUAL INSPECTION OF FLAME
Verify proper operation after servicing. The
burner must flame evenly over the entire
surface when operating correctly. The flame
must burn with a clear, blue, stable flame. See
the parts breakdown of the burner for the
location of the view ports.
The flame pattern should be as shown in the
images below:
Testing the pressure relief valve should
only be performed by a trained and
qualified professional. Water discharged
from the pressure relief valve could cause
severe burns instantly or death from scalds.
WARNING
Flame
Rod
SATISFACTORY
FRONT VIEW
Blue Flame
Figure 88
Flame
Rod
UNSATISFACTORY
FRONT VIEW
Yellow Flame
Figure 89
Clean burner if the flame pattern does not
look satisfactory.
84 Rinnai Tankless Water Heater Installation and Operation Manual
FREEZE PROTECTION
Make sure in case of freezing weather that the water heater and its water lines are adequately protected
to prevent freezing. Damage due to freezing is not covered by the warranty. Refer to the “Freeze
Protection” section (Section 4.3 Choose an Installation Location > Freeze Protection). The water heater
may be drained manually. However, it is highly recommended that drain down solenoid valves be
purchased and installed, which will automatically drain the water heater if power is lost. (The condensate
trap drain plug and Pressure Relief Valve are not affected by the auto drain down solenoid valves and will
have to be manually opened.)
WINTERIZATION
The following recommendations are intended to suggest practices that are effective for winterizing the
water heater. They should be used as a guide only. No liability is assumed for any issues resulting from
the use of this information.
Note: See section “6.4 Draining the Water Heater” for detailed instructions on:
•
Draining the water heater
•
Running a low volume of water through the water heater to prevent freezing
•
Steps to take when the water heater or external pipes have frozen
Figure 90
IMPORTANT
DO NOT operate this water heater if the
air filter is not in place.
INSPECTION
•
To maintain optimum performance,
periodically inspect the air filter.
•
If the air filter appears to have lint and/or
dust build up, follow the cleaning
procedure described below.
•
If the air filter appears damaged, contact
a trained and qualified professional for a
replacement air filter assembly.
CLEANING
1. Power OFF the water heater:
•
Push the “On/Off” button located on
the right-hand side of the controller.
The display will go blank when the
power is off.
2. Remove the front panel:
•
Remove the two screws securing the
front panel and release the two
latches.
•
Remove the front panel and locate the
filter at the upper right-hand corner of
the water heater.
•
Remove the air filter by pulling out the
“FILTER Pull to Clean” tab.
3. Clean the air filter:
•
With mild dish soap and a soft bristle brush, scrub the filter area of the air filter door.
•
With clean water, rinse the soap off the filter.
4. Dry the air filter:
•
With a lint free towel, dry the air filter.
5. Inspect and Replace the air filter:
•
Inspect the air filter for any debris that may restrict air flow to the water heater.
•
If the filter still appears dirty repeat the cleaning steps.
•
Replace the air filter.
6. Install the front panel and power ON the water heater.
Rinnai Tankless Water Heater Installation and Operation Manual 85
A
………B
This water heater includes a service indicator/reminder (Service Soon,
SS
). When selected in the
parameter settings, an
SS
code will display on the controller indicating that it is time to flush and
service the water heater. An LC diagnostic code also indicates the unit is beginning to lime/scale up
and must be flushed. Failure to flush the appliance will cause damage to the heat exchanger.
Damage caused by lime/scale build-up is not covered by the water heater’s warranty. Rinnai strongly
recommends installation of isolation valves to allow for flushing of the heat exchanger.
1. Shut off gas supply and turn off the controller.
2. Close the shutoff valves on both the hot water and cold water lines (V3 and V4).
3. Connect pump outlet hose (H1) to the cold water line at service valve (V2).
4. Connect drain hose (H3) to the hot water line at service valve (V1).
5. Pour four gallons of undiluted virgin, food grade, white vinegar into pail.
6. Place the drain hose (H3) and the hose (H2) to the pump inlet into the cleaning solution.
7. Open both service valves (V1 and V2) on the hot water and cold water lines.
8. Remove the water heater front panel by removing two screws and releasing two latches.
9. Locate the PC Board at lower of unit (Figure 92).
10. Locate the push buttons (A and B) on the PC board.
11. Press the “B” button for 1 second and release when display shows “dES” (descaling). Push the
“A” button. “dES” starts blinking.
Figure 91
Figure 92
Figure 93
dES
86 Rinnai Tankless Water Heater Installation and Operation Manual
Scale build-up will affect the performance of the water heater. Water should be treated. Rinnai offers
Southeastern Filtration’s “ScaleCutter Water Conditioning System” that provides superior lime scale
prevention and corrosion control by feeding a blend of scale control compounds into the cold water supply.
NOTE
12. Operate the pump and allow the vinegar to circulate through the water heater for at least 1 hour
at a rate of four gallons per minute (15.1 liters per minute).
13. Display shows “60” (Figure 94) which indicates the remaining flush time in minutes. The number
decreases by 1 every minute. For some reasons, flushing needs to be paused, stop the pump.
The number on the display does not decrease while the unit does not detect water flow. When
the pump resumes operation, the remaining flush time resumes decreasing as well.
15. Turn off the pump.
16. Rinse the vinegar from the water heater as follows:
A. Remove the free end of the drain hose (H3) from the pail. Place in sink or outside to drain.
B. Close service valve (V2) and open shutoff valve (V4). Do not open shutoff valve (V3).
C. Allow water to flow through the water heater for five minutes.
D. Close shutoff valve (V4). When unit has finished draining remove the in-line filter at the cold
water inlet and clean out any residue. Place filter back into unit and open valve (V4).
E. Close service valve (V1) and open shutoff valve (V3).
17. Push the power button, and the display shows “End” (Figure 96).
14. After 60 minutes flushing time completes, display shows “rnS” (rinsing) (Figure 95) and beeping
sound is observed.
18. Disconnect all hoses.
19. Install the front panel, restore gas supply to the water heater, and push the power button twice
on the controller to put the unit back to normal mode.
Figure 95
Figure 94
Figure 96
End
rnS
60
Rinnai Tankless Water Heater Installation and Operation Manual 87
If the water heater is not going to be used
during a period of possible freezing weather, it
is recommended that the water inside the
water heater be drained.
To manually drain the water:
1. Shut off cold water supply and gas supply.
2. Turn off the controller.
3. Disconnect the power to the water heater.
4. Close the hot and cold isolation valves.
5. Open the pressure relief valve (PRV)
lever.
6. Open the hot and cold drain valves.
7. Remove the condensate trap drain plug
and allow to drain.
8. Remove the pump drain plug (for RXP
models only).
To resume normal operation:
1. Confirm that the gas supply is turned off,
all taps are closed and PRV lever is
closed.
2. Insert the condensate trap drain plug.
3. Insert the pump drain plug (for RXP
models only).
4. Close the hot and cold drain valves.
5. Open the cold and hot water isolation
valves.
6. Open a tap and confirm that water flows,
and then close.
7. Connect power to the water heater.
8. After confirming that the controller is off,
turn on the gas supply.
9. Turn on the controller.
To avoid burns, wait until the equipment
cools down before draining the water. The
water in the appliance will remain hot after it
is turned off.
WARNING
Running a low volume of water through the
water heater to prevent freezing:
If the temperature exceeds the ability of the
water heater to freeze protect itself, or if power
is lost, the following steps may prevent the
water heater and external piping from freezing.
Units connected with EZConnect™ (2-unit link)
should be drained to prevent freezing if not in
use.
1. Turn the water heater off
and close the gas supply
valve.
2. Turn on a hot water tap
to flow water about 0.1
gal/min (0.4 L/min) or
where the stream is
about 0.2 in. (5 mm) thick.
When the water heater or external piping
has frozen:
1. Do not operate the water heater if it or the
external piping is frozen.
2. Close the gas and water valves and turn off
the power.
3. Wait until the water thaws. Check by
opening the water supply valve.
4. Check the water heater and the piping for
leaks.
Figure 97
Condensate
Drain Trap Plug
Hot Drain Valve
Cold
Drain
Valve
Figure 98
Pressure
Relief
Valve
Cold
Isolation
Valve
Hot
Isolation
Valve
88 Rinnai Tankless Water Heater Installation and Operation Manual
For Gas Models Sold in Massachusetts
NOTICE BEFORE INSTALLATION:
This direct-vent appliance must be installed by
a properly trained and qualified professional. If
you are not properly trained, you must not
install this unit.
IMPORTANT: In the State of Massachusetts
(248 CMR 4.00 & 5.00):
For all side wall horizontally vented gas fueled
equipment installed in every dwelling, building
or structure used in whole or in part for
residential purposes, including those owned or
operated by the Commonwealth and where the
side wall exhaust vent termination is less than 7
ft above finished grade in the area of the
venting, including but not limited to decks and
porches, the following requirements shall be
satisfied:
1. INSTALLATION OF CARBON MONOXIDE
DETECTORS. At the time of installation of
the side wall horizontal vented gas fueled
equipment, the installing plumber or gas
fitter shall observe that a hard-wired carbon
monoxide detector with an alarm and
battery back-up is installed on the floor
level where the gas equipment is to be
installed.
Topics in this section
In addition, the installing plumber or gas fitter
shall observe that a battery operated or hard
wired carbon monoxide detector with an alarm
is installed on each additional level of the
dwelling, building or structure served by the
side wall horizontal vented gas fueled
equipment. It shall be the responsibility of the
property owner to secure the services of a
trained and qualified professional for the
installation of hard-wired carbon monoxide
detectors.
A. In the event that the side wall,
horizontally vented gas fueled
equipment is installed in a crawl space
or an attic, the hard-wired carbon
monoxide detector with alarm and
battery back-up may be installed on the
next adjacent floor level.
B. In the event that the requirements of this
subdivision cannot be met at the time of
completion of installation, the owner
shall have a period of thirty (30) days to
comply with the above requirements;
provided, however, that during said
thirty (30) day period, a battery operated
carbon monoxide detector with an alarm
shall be installed.
2. APPROVED CARBON MONOXIDE
DETECTORS. Each carbon monoxide
detector as required in accordance with
the above provisions shall comply with
NFPA 720 and be ANSI/UL 2034 listed
and IAS certified.
3. SIGNAGE. A metal or plastic identification
plate shall be permanently mounted to the
exterior of the building at a minimum
height of 8 ft above grade directly in line
with the exhaust vent terminal for the
horizontally vented gas fueled heating
appliance or equipment. The sign shall
read, in print size no less than one-half
(1/2) inch in size, “GAS VENT DIRECTLY
BELOW. KEEP CLEAR OF ALL
OBSTRUCTIONS.”
4. INSPECTION. The state or local gas
inspector of the side wall horizontally
vented gas fueled equipment shall not
approve the installation unless, upon
inspection, the inspector observes carbon
monoxide detectors and signage installed
in accordance with the provisions of 248
CMR 5.08(2)(a)1 through 4.
•
Massachusetts State Gas Regulations
•
Wiring Diagram
•
Ladder Diagram
•
Pressure Drop Curves
•
Water Flow and Pump Performance
Curves
•
Guidelines for Additional Temperature
Controllers
•
Bluetooth Low Energy (BLE) and App
Instructions
•
Federal Communication Commission
Interference Statement
•
Industry Canada Statement
Rinnai Tankless Water Heater Installation and Operation Manual 89
COMBINATION SPACE HEATING/POTABLE WATER SYSTEM
(For Use In Commonwealth of Massachuses)
When the system requires water for space heating at temperatures higher than required for other uses, a means such
as a mixing valve shall be installed to temperature the water for those uses in order to reduce scald hazard potential.
Air handler
Use Only in Commonwealth of Massachusetts
Electronically controlled
pump timer. Activates every
6 hours for 60 seconds.
Wire to product approved
pump. (or built
- in pump)
Hot Water
Supply and
Return to
Heating Coil
Tempered water to plumbing fixtures. Must
meet temperature requirements of 248 CMR
Automatic Tempering Device Must be installed
below the top of the water heater as per
manufacturer's recommendations.
Check Valve
Cold Water
Supply
Shut Off Valve
Check Valve with 1/8in. Hole
Drilled in Clapper Optional
Expansion
Tank
Product
Approved
Water Heater
100'-00" maximum distance from water
heater to fan coil and back. (Developed
length) not including coil in heating unit.
Piping loop between
water heater and fan coil
shall be in compliance
with 248 CMR.
NSF-61 Product
Approved Pump
Check Valve
Gas supply
Min. 2' developed
length Type L copper
from water heater
Air handler
Combination Space
Heating/Potable
Water System
All water piping should be
insulated in accordance with
780 CMR (Massachusetts
Energy Code)
Hot water coil
System installed with reverse
acting aquastat to shutoff
fan. Suggested but not
required by 248 CMR.
Figure 99
90 Rinnai Tankless Water Heater Installation and Operation Manual
PC BOARD
Figure 100
Rinnai Tankless Water Heater Installation and Operation Manual 91
Figure 101
92 Rinnai Tankless Water Heater Installation and Operation Manual
Pressure Drop Curve: Metric (SI) System:
Figure 102
Pressure Drop Curve: Imperial (Brish) System:
Rinnai Tankless Water Heater Installation and Operation Manual 93
Figure 103
Water Flow Curve:
NOTE: Maximum flow rates may vary based on set temperature, Delta T and altitude.
Pump Performance Curve:
94 Rinnai Tankless Water Heater Installation and Operation Manual
Number of
Wired
Controllers
Maximum Cable Length
for Each Controller to
Water Heater
1 328 ft (100 m)
2 164 ft (50 m)
3 65 ft (20 m)
Cable Lengths and Sizes
The temperature controller cable should be a
non- polarized two-core cable with a minimum
gauge of 22 AWG. The maximum cable length
from each temperature controller to the water
heater depends on the total number of wired
controllers connected to the water heater.
All Rinnai Tankless Water Heaters are equipped with an integrated digital temperature controller that
allows for a precise water temperature set- point. Additional digital temperature controllers are
available as accessories and must be purchased separately (detailed installation steps included with
purchase).
Wiring
A maximum of four temperature controllers can be installed for a water heater or bank of water
heaters; this includes the controller built into a Rinnai Tankless Water Heater. Controllers can only
be wired in parallel; they cannot be wired in series.
Location
•
The temperature controller should be out of reach of small children.
•
Avoid locations where the temperature controller may become hot (near an oven or radiant
heater).
•
Avoid locations in direct sunlight. The digital display may be difficult to read in direct sunlight.
•
Avoid locations where the temperature controller could be splashed with liquids.
•
Do not install in locations where the temperature controller can be adjusted by the public.
•
DO NOT install the MC-195T-US Timer/Controller and Wi-Fi Module together as they are
not compatible accessories.
•
SmartCirc™ is not available with the use of MC195T or Wi-Fi module.
IMPORTANT
Table 39
Connect controller cable to
mating terminal at middle right
side of PC Board.
Wi-Fi Module
Figure 105
Wiring illustration (Detailed
wiring instructions included with
temperature controller package)
Figure 104
OR
Four
Temperature
Controllers
Rinnai
Rinnai
Rinnai
Enlarged view
of controller
Rinnai
Rinnai
Rinnai
Rinnai
Temperature Controllers
Rinnai
Rinnai
Rinnai
Rinnai Tankless Water Heater Installation and Operation Manual 95
Instructions on this page are correct at the time of publishing; however, these instructions may be
updated without notice. To make sure you have the most current instructions, please visit
rinnai.us/wifi (for United States installations) or rinnai.ca/wifi (for Canadian installations).
To download the Rinnai Central app:
1. Scan the QR code shown to the right.
2. Download the Rinnai Central app from the app store.
To configure your tankless water heater using the Rinnai Central app:
Note: To use the Rinnai Central app BLE feature with your tankless water heater,
your connecting device (smartphone, tablet, computer, etc) must support Bluetooth
4.0 or newer. Contact your connecting device manufacturer if you are not sure if
your device supports Bluetooth 4.0 or newer.
1. Press and release the Bluetooth button on the controller. The Bluetooth
LED on the controller turns solid blue.
2. Log into the Rinnai Central app with a professional account and choose “Connect to a
Rinnai Tankless Water Heater.”
3. Follow the Rinnai Central app through setting up your tankless water heater.
To connect a Rinnai BLE push button to your tankless water heater:
1. Press and hold the Bluetooth button on the controller until the Bluetooth LED on the
controller starts blinking.
2. Press and hold the Rinnai BLE push button until the Bluetooth LED on the controller stops
blinking. Now the Rinnai BLE push button is paired with your tankless water heater.
Pressing the Rinnai BLE push button starts recirculation of your tankless water heater.
Figure 106
Figure 107
Sample Screen
96 Rinnai Tankless Water Heater Installation and Operation Manual
FCC Interference Statement:
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two
conditions: (1) This device may not cause harmful interference, and (2) this device must accept any
interference received, including interference that may cause undesired operation.
This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This equipment generates, uses and can
radiate radio frequency energy and, if not installed and used in accordance with the instructions,
may cause harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by turning the equipment off
and on, the user is encouraged to try to correct the interference by one of the following measures:
− Reorient or relocate the receiving antenna.
− Increase the separation between the equipment and receiver.
− Connect the equipment into an outlet on a circuit different from that to which the receiver is
connected.
− Consult the dealer or an experienced radio/TV technician for help.
FCC Caution: Any changes or modifications not expressly approved by the party responsible for
compliance could void the user's authority to operate this equipment.
This transmitter must not be co-located or operating in conjunction with any other antenna or
transmitter.
Radiation Exposure Statement:
The product comply with the FCC portable RF exposure limit set forth for an uncontrolled
environment and are safe for intended operation as described in this manual. The further RF
exposure reduction can be achieved if the product can be kept as far as possible from the user body
or set the device to lower output power if such function is available.
Rinnai Tankless Water Heater Installation and Operation Manual 97
IC
This device complies with ISED’s licence-exempt RSSs. Operation is subject to the following two
conditions: (1) This device may not cause harmful interference, and (2) this device must accept any
interference received, including interference that may cause undesired operation.
Le présent appareil est conforme aux CNR d’ ISED applicables aux appareils radio exempts de
licence. L’exploitation est autorisée aux deux conditions suivantes : (1) le dispositif ne doit pas
produire de brouillage préjudiciable, et (2) ce dispositif doit accepter tout brouillage reçu, y compris
un brouillage susceptible de provoquer un fonctionnement indésirable.
Radiation Exposure Statement:
This equipment complies with ISED radiation exposure limits set forth for an uncontrolled
environment. This equipment should be installed and operated with minimum distance 20cm
between the radiator & your body.
Déclaration d'exposition aux radiations:
Cet équipement est conforme aux limites d'exposition aux rayonnements ISED établies pour un
environnement non contrôlé. Cet équipement doit être installé et utilisé avec un minimum de 20 cm
de distance entre la source de rayonnement et votre corps.
98 Rinnai Tankless Water Heater Installation and Operation Manual
What is Covered?
The Rinnai Standard Limited Warranty covers any defects in materials or workmanship when the
product is installed and operated according to Rinnai written installation instructions, subject to the
terms within this Limited Warranty document. This Limited Warranty applies only to products that are
installed correctly in the United States and Canada. Improper installation may void this Limited
Warranty. It is recommended that a trained and qualified professional who has attended a Rinnai
installation training class complete your installation. This Limited Warranty coverage, as set out in
the table below, extends to the original purchaser and subsequent owners, but only while the
product remains at the site of the original installation, and terminates if the product is moved or
reinstalled at a new location.
1
For residential applications, the heat exchanger warranty is 15 years or 12,000 operation hours,
whichever occurs first.
2
For commercial applications, the heat exchanger warranty is 8 years or 12,000 operation hours,
whichever occurs first.
Notes:
•
From date of purchase, period of coverage is reduced to 8 years or 12,000 operation hours,
whichever occurs first, if the Rinnai Tankless Water Heater temperature settings exceed 160°F
(71°C).
•
The integrated controller has a 1 year warranty on parts.
What Will Rinnai Do?
Rinnai will repair or replace the covered product or any part or component that is defective in materials
or workmanship as set forth in the above table. Rinnai will pay reasonable labor charges associated
with the repair or replacement of any such part or component during the term of the labor warranty
period. All repair parts must be genuine Rinnai parts. All repairs or replacements must be performed
by a qualified professional who is properly trained to do the type of repair.
Replacement of the product may only be authorized by Rinnai at its sole discretion. Rinnai does not
authorize any person or company to assume for it any obligation or liability in connection with the
replacement of the product. If Rinnai determines that repair of a product is not possible, Rinnai may
replace the product with a comparable product at Rinnai’s sole discretion. The warranty claim for
product parts and labor may be denied if a component or product returned to Rinnai is found to be free
of defects in material or workmanship; damaged by improper installation, use or operation; or
damaged during return shipping.
How To Obtain Service
For the name of a trained and qualified professional, please contact your place of purchase, visit the
Rinnai website (www.rinnai.us), call Rinnai at 1-800-621-9419 or write to Rinnai at 103 International
Drive, Peachtree City, Georgia 30269.
Proof of purchase is required to obtain warranty service. You may show proof of purchase with a
dated sales receipt, or by registering within 30 days of purchasing the product. To register your Rinnai
Tankless Water Heater, please visit www.rinnai.us. For those without internet access, please call 1-
800-621-9419. Receipt of registration by Rinnai will constitute proof-of-purchase for this product.
Registration of product installed in new home construction may be verified with a copy of the closing
papers provided by the initial home buyer. However, registration is not necessary in order to validate
this Limited Warranty.
Item
Period of Coverage (From Date of Purchase)
Residential Applications Commercial Applications
Heat Exchanger
15 Years
1
8 Years
2
All Other Parts and Components
5 Years 5 Years
Reasonable Labor
1 Year 1 Year
Table 40
Rinnai Tankless Water Heater Installation and Operation Manual 99
What Is Not Covered?
This Limited Warranty does not cover any failures or operating difficulties due to the following:
•
Accident, abuse, or misuse
•
Alteration of the product or any component part
•
Misapplication of this product
•
Improper installation (such as but not limited to):
•
Product being installed in a corrosive environment
•
Condensate damage
•
Improper venting
•
Incorrect gas type
•
Incorrect gas or water pressure
•
Absence of a drain pan under the appliance
•
Improper maintenance (such as but not limited to scale build-up, freeze damage, or vent
blockage)
•
Incorrect sizing
•
Any other cause not due to defects in materials or workmanship
•
Problems or damage due to fires, flooding, electrical surges, freezing or any acts of God
•
Any damage caused by poor water quality
•
Operating the water heater with anything other than potable water at all times
•
Force majeure
There is no warranty coverage on product installed in a closed loop application, commonly
associated with space heating only applications.
This Limited Warranty does not apply to any product whose serial number or manufacture date has
been defaced.
This Limited Warranty does not cover any product used in an application that uses chemically
treated water such as a pool or spa heater.
Limitation on Warranties
No one is authorized to make any other warranties on behalf of Rinnai America Corporation. Except
as expressly provided herein, there are no other warranties, expressed or implied, including, but not
limited to warranties of merchantability or fitness for a particular purpose, which extend beyond the
description of the warranty herein.
Any implied warranties of merchantability and fitness arising under state law are limited in duration to
the period of coverage provided by this Limited Warranty, unless the period provided by state law is
less. Some states do not allow limitations on how long an implied Limited Warranty lasts, so the
above limitation may not apply to you.
Rinnai shall not be liable for indirect, incidental, special, consequential or other similar damages that
may arise, including lost profits, damage to person or property, loss of use, inconvenience, or liability
arising from improper installation, service or use. Some states do not allow the exclusion or limitation
of incidental or consequential damages, so the above limitation may not apply to you.
This Limited Warranty gives you specific legal rights, and you may also have other rights which vary
from state to state.
www.rinnai.us/warranty
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