Tankless Water Heater (With Pump)
Installation and Operation Manual
06000012350449
U334-0777X01(00)
INTERNAL (INDOOR) MODELS:
RSC199i (REU-NP3237FF-US(A))
RSC160i (REU-NP2530FF-US(A))
EXTERNAL (OUTDOOR) MODELS:
RSC199e (REU-NP3237W-US(A))
RSC160e (REU-NP2530W-US(A))
C
US
ANSI Z21.10.3 ・ CSA 4.3
2 Rinnai Tankless Water Heater Installation and Operation Manual
WARNING
If the information in these instructions is not followed exactly, a re or explosion may result
causing property damage, personal injury, or death.
• Do not store or use gasoline or other ammable 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 re department.
• Installation and service must be performed by a trained and qualied professional, service
agency or the gas supplier.
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.
• Ne pas entreposer ni utiliser d’essence ou ni d’autres vapeurs ou liquides inammables 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
qualié ou par le fournisseur de gaz.
AVERTISSEMENT
Full-length French and Spanish versions available online at rinnai.us
Rinnai Tankless Water Heater Installation and Operation Manual 3
Contents
1. Welcome .......................................................................................................................................... 5
2. Safety ............................................................................................................................................... 6
2.1 Safety Symbols ....................................................................................................................... 7
2.2 Safety Precautions .................................................................................................................. 7
3. About the Water Heater .................................................................................................................. 9
3.1 Front View ............................................................................................................................... 9
3.2 Bottom View .......................................................................................................................... 10
3.3 Components ......................................................................................................................... 11
3.4 Specications ........................................................................................................................ 12
3.5 Dimensions ........................................................................................................................... 13
3.6 Accessories .......................................................................................................................... 15
4. Install the Water Heater ................................................................................................................ 17
4.1 Installation Guidelines .......................................................................................................... 17
4.2 What You Will Need .............................................................................................................. 18
4.3 Choose an Installation Location ............................................................................................ 19
4.4 Mount the Water Heater to the Wall ...................................................................................... 24
4.5 Vent the Water Heater .......................................................................................................... 26
4.6 Connect Water Supply .......................................................................................................... 50
4.7 Install the Isolation Valves .................................................................................................... 51
4.8 Install Pressure Relief Valve ................................................................................................. 52
4.9 Connect Condensate Drain .................................................................................................. 54
4.10 Connect the Gas Supply ....................................................................................................... 57
4.11 Connect the Power Supply ................................................................................................... 60
4.12 Congure Parameter Settings ............................................................................................. 61
4.13 Post-Water Heater Installation Checklist ............................................................................. 63
5. Operation ....................................................................................................................................... 65
5.1 Safety Precautions ................................................................................................................65
5.2 Operating Instructions ...........................................................................................................67
5.3 Control Panel ........................................................................................................................68
5.4 Setting the Temperature .......................................................................................................69
5.5 Performance Data .................................................................................................................70
4 Rinnai Tankless Water Heater Installation and Operation Manual
5.6 Diagnostic Codes ..................................................................................................................72
5.7 Conguring Recirculation .....................................................................................................75
6. Maintenance .................................................................................................................................. 81
6.1 Maintenance ......................................................................................................................... 81
6.2 Cleaning and Inspecting the Air Filter (Indoor Units Only) .................................................... 83
6.3 Flushing the Heat Exchanger ............................................................................................... 85
6.4 Draining the Water Heater .................................................................................................... 86
7. Appendices ................................................................................................................................... 87
7.1 Massachusetts State Gas Regulations ................................................................................. 87
7.2 Wiring Diagram ..................................................................................................................... 89
7.3 Ladder Diagram .................................................................................................................... 90
7.4 Pressure Drop and Water Flow Curves ................................................................................ 91
7.5 Pump Performance Curve .................................................................................................... 92
7.6 Guidelines for Additional Temperature Controllers ............................................................... 93
8. Warranty ........................................................................................................................................ 94
Rinnai Tankless Water Heater Installation and Operation Manual 5
ANSI American National Standards
Institute
BTU British Thermal Unit
DHW Domestic Hot Water
GPM Gallons per minute
LPG Liqueed Petroleum Gas
NG Natural Gas
PP Polypropylene
PRV Pressure Relief Valve
PSI Pounds per square inch
WC Inches of water column
To The Consumer
• You must read the entire manual to
properly operate the water heater and to
have regular maintenance performed.
• Keep this manual for future reference.
• As when using any appliance generating
heat, there are certain safety precau-
tions you should follow. See section “2.2
Safety Precautions” for detailed safety
precautions.
• Be sure your water heater is installed by
a trained and qualied professional.
• If installing in the state of Massachu-
setts, you must read section “7.1 Massa-
chusetts State Gas Regulations” in this
manual.
Acronyms and Abbreviations
Following is a list of common acronyms and
abbreviations used in this 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.
To The Installer
• It is recommended that a trained and
qualied professional who has attended
a Rinnai training class complete your
installation. The warranty may be voided
due to any improper installation.
• The trained and qualied 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 on installation of 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 installer.
• When installation is complete, leave
this manual with the water heater (for
internal/indoor units) or give the manual
directly to the consumer.
1. 1. WelcomeWelcome
Table 1
WARNING AVERTISSEMENT
6 Rinnai Tankless Water Heater Installation and Operation Manual
• Assurez-vous de bien suivre les instruc-
tions données dans cette notice pour
réduire au minimum le risque d’incend-
ie ou d’explosion ou pour éviter tout
dommage matériel, toute blessure ou la
mort.
• Ne pas entreposer ni utiliser d’essence
ou ni d’autres vapeurs ou liquides in-
ammables 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 fournis-
seur.
– 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 qualié ou par le fournisseur
de gaz.
• Les panneaux d’avertissement de ce
manuel sont ici pour éviter de vous
blesser et d’autres personnes. Suivez-
les explicitement.
• If the information in these instructions is
not followed exactly, a re or explosion
may result causing property damage,
personal injury, or death.
• Do not store or use gasoline or other
ammable 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 re department.
• Installation and service must be per-
formed by a trained and qualied
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.
2. 2. SafetySafety
WARNING
CAUTION
WARNING
Rinnai Tankless Water Heater Installation and Operation Manual 7
2.2 Safety Precautions
The following precautions apply to the installer and
consumer. Read and follow all instructions in this
section.
DO NOT adjust the inter-
nal gas valve.
The design is such that adjustment is not re-
quired. Warranty may be voided if the internal gas
valve is adjusted.
• Before operating, smell all around the ap-
pliance area for gas. Be sure to smell next
to the oor because some gas is heavier
than air and will settle on the oor.
• Keep the area around the appliance clear
and free from combustible materials,
gasoline, and other ammable vapors and
liquids.
• Combustible construction refers to adja-
cent walls and ceiling and should not be
confused with combustible or ammable
products and materials. Combustible and/
or ammable products and materials
should never be stored in the vicinity of
this or any gas appliance.
• Always check the water temperature be-
fore entering a shower or bath.
• To protect yourself from harm, before per-
forming maintenance:
– Turn o the electrical power supply by
unplugging the power cord or by turning
o the electricity at the circuit breaker.
(The temperature controller does not
control the electrical power.)
– Turn o the gas at the manual gas con-
trol valve, usually located immediately
below the water heater.
– Turn o the incoming water supply.
This can be done at the isolation valve
immediately below the water heater or
by turning o the water supply to the
building.
Safety alert symbol. Alerts you to
potential hazards that can kill or hurt
you and others.
Indicates an imminently
hazardous situation which,
if not avoided, will result in
personal injury or death.
DANGER
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.
Indicates an imminently
hazardous situation which,
if not avoided, will result in
personal injury or death.
2.1 Safety Symbols
8 Rinnai Tankless Water Heater Installation and Operation Manual
• DO NOT operate the water heater with-
out the front panel installed. The front
panel should only be removed for ser-
vice/maintenance or replacing internal
components.
• BURN HAZARD. Hot exhaust and vent
may cause serious burns. Keep away
from the water heater. Keep small chil-
dren and animals away from the water
heater.
• Hot water outlet pipes leaving the water
heater can be hot to touch.
• Do not store or use gasoline or other
ammable 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 inam-
mables à proximité de cet appareil ou de
tout autre appareil.)
• Install the vent system per local and
national codes.
• Do not install this water heater above
10,200 ft (3,109 m).
• Do not obstruct combustion air to the
water heater.
• Failure to properly vent this appliance
can result in death, personal injury and/
or property damage.
• 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.
– Use only your hand to turn the manu-
al 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 qualied profes-
sional. Force or attempted repair may
result in a re or explosion.
• Do not use this appliance if any part
has been under water. Immediately call
a trained and qualied professional to
inspect the appliance and to replace any
part of the control system and any man-
ual gas control valve 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 com-
mande qui ont été plongés dans l’eau.)
• Do not use substitute materials. Use only
parts certied for the appliance.
• Should overheating occur or the gas
supply fail to shut o, turn o the manual
gas control valve to the appliance.
(En cas de surchaue ou si l’alimen-
tation en gaz ne s’arrête pas, fermez
manuellement le robinet d’arrêt de l’ad-
mission de gaz.)
• Only trained and qualied profession-
als 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.
• Proper venting is required for the safe
operation of this appliance.
• Flammable liquids such as cleaning
solvents, aerosols, paint thinners, ad-
hesives, gasoline and propane must be
handled and stored with extreme care.
These ammable liquids emit ammable
vapors and when exposed to an ignition
source can result in a re hazard or
explosion. Flammable liquids should not
be used or stored in the vicinity of this or
any other gas appliance.
Rinnai Tankless Water Heater Installation and Operation Manual 9
3. 3. About the Water HeaterAbout the Water Heater
3.1 Front View
Indoor Outdoor
Topics in this section
• Front View
• Bottom View
• Components
• Specications
• Dimensions
• Accessories
Controller
Piping Connections
Vent
Connections
Exhaust
Duct
Figure 1: Front View
10 Rinnai Tankless Water Heater Installation and Operation Manual
3.2 Bottom View
Gas
Hot Water
Outlet
Cold Water
Inlet
Pressure Relief
Valve
Figure 2: Bottom View
Rinnai Tankless Water Heater Installation and Operation Manual 11
3.3 Components
Air Intake
Burner Assembly
Ignition Unit
PC Board
Integrated
Pump
Heat Exchanger
Gas Valve
Flue Gas Exhaust
Air Inlet Filter
Fan with Integrated
Venturi
Silencer
Bypass Flow
Servo Valve
Intake
Exhaust
Water Flow
Servo Valve
Controller removed
for clarity.
Pump PC Board
Figure 3: Components
12 Rinnai Tankless Water Heater Installation and Operation Manual
3.4 Specifications
Indoor Units Outdoor Units
RSC199i RSC160i RSC199e RSC160e
Minimum Gas Consumption
Btu/h
15,000
Maximum Gas
Consumption Btu/h
199,000 160,000 199,000 160,000
Flow Rate
1
(Min-Max)
0.26-9.8 GPM
(1.0-37 L/min)
0.26-8.0 GPM
(1.0-30 L/min)
0.26-9.8 GPM
(1.0-37 L/min)
0.26-8.0 GPM
(1.0-30 L/min)
Max Flow Rate
with Parameter Adjustment
11 GPM (42 L/min) 9 GPM (34 L/min) 11 GPM (42 L/min) 9 GPM (34 L/min)
Weight
68 lb (31 kg) 66 lb (30 kg) 68 lb (31 kg) 66 lb (30 kg)
Sound Level
49 dB 48 dB 53 dB 52 dB
Electrical Data
Normal
78 W 57 W 78 W 55 W
Standby
2.3 W
Freeze Protection
150 W 172 W
Max Current
4 Amps
Fuse
10 Amps
Temperature Setting
Minimum: Normal Operation: 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,
Continuous Flow Gas Hot Water System
Ignition System
Direct Electronic Ignition
Electric Connections
Appliance: AC 120 Volts, 60Hz
Temperature Controller: DC 12 Volts (Digital)
Water Supply Pressure
Minimum: 50 PSI (Recommended 60-80 PSI for maximum performance)
Maximum: 150 PSI
Remote Control Cable
Non-Polarized Two Core Cable (Minimum 22 AWG)
Complies with South Coast
Air Quality Management
District 14 ng/J or 20 ppm
NOx emission levels
Yes
1
Minimum ow may vary slightly depending on the temperature setting and the inlet water temperature. Minimum activation ow is
0.4 GPM (1.5 L/min).
2
The maximum gas supply pressure must not exceed the value specied by the manufacturer.
Rinnai products are continually being updated and improved; therefore, specications are subject to change without prior notice.
Table 2: Specications
Rinnai Tankless Water Heater Installation and Operation Manual 13
3.5 Dimensions
Measurements: in. (mm)
Indoor Models
(RSC199i and RSC160i)
Front Panel View Side Panel View
Outdoor Models
(RSC199e and RSC160e)
Front Panel View Side Panel View
Vent Connection:
2 in. (51 mm) nominal
PVC/Polypropylene or 3
in./5 in. Concentric.
Figure 4: Indoor Dimensions
Figure 5: Outdoor Dimensions
14 Rinnai Tankless Water Heater Installation and Operation Manual
5.6 (142.2)
5.31 (135)
7.72 (196)
5.31 (135)
2.8 (71)
7.6 (193)
6.56 (166.7)
1.22 (31.1)
Cold Inlet
Gas
Hot Outlet
Condensate
Drain
Pressure
Relief Valve
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
Pressure Relief Valve M33 Thread
3.5.1 Supply Connections
Table 3: Supply Connections
3.15 (79.91)
.10 (2.57)
.59 (15)
Figure 6: Supply Connections
Rinnai Tankless Water Heater Installation and Operation Manual 15
Product Product Description Image
Room Air Screen
Part #: 108000105
Recommended room air screen for use in
room air applications only.
Condensate Neutralizer
Part #: 804000074
Neutralizes the condensate generated by
the water heater.
ScaleCutter
Part #: 103000038
Filters and reduces the amount of scale
entering the water heater allowing for
greater water heater longevity.
ScaleCutter Rell
Cartridge
Part #: 103000039
Rell cartridge for the ScaleCutter lter
assembly.
Drain Down Kit
Part #: 104000059
Provides freeze protection by immediate-
ly draining the water heater upon loss of
power.
Additional Controller
Part #: MC-601-BK
MC-601-W
MC-195T-US
MCC-91-2
MCC-601
Additional controllers are available for
user convenience.
Recess Box
Part #: RGB-CTWH-4
Allows an external (outdoor) water heater
to be recessed into a wall.
Pipe Cover
Part #: PCD07-SM
Encloses the piping below the water
heater for aesthetic purposes.
control•r™ Wi-Fi Mod-
ule (And Accessories)
Part #: RWM101
Controls On-Demand recirculation, re-
motely adjust temperatures, and commu-
nicates with the service provider portal.
The control•r™ Wi-Fi Module and MC-
195T-US controller are not compatible
accessories and must not be installed
together.
3.6 Accessories
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
16 Rinnai Tankless Water Heater Installation and Operation Manual
Product Product Description Image
EZConnect™ Cable
Part #: REU-EZC-2
Electronically connects two water heaters
and allows them to function as one hot
water source.
Push Button
Part #: RWMPB02
Mounted in a convenient location, such
as a kitchen faucet or bathroom sink,
the wireless push button works with the
control•r™ Module to operate the tank-
less water heater recirculation system by
pushing the button.
Motion Sensor
Part #: RWMMS02
Mounted near the point of use, like a
kitchen faucet or bathroom sink, the wire-
less motion sensor works with the con-
trol•r™ Module to operate the tankless
water heater recirculation system with the
detection of motion.
Rinnai Tankless Water Heater Installation and Operation Manual 17
4. 4. Install the Water HeaterInstall the Water Heater
THIS SECTION IS INTENDED FOR THE
INSTALLER
Installer qualications: A trained and qualied
professional must install the appliance, inspect
it, and leak test the water heater before
use. The warranty will be voided due to any
improper installation. The trained and qualied
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
www.trainingevents.rinnai.us.
4.1 Installation
Guidelines
When installing the water heater, follow these
guidelines:
• This water heater is certied for instal-
lation in residential applications and
manufactured (mobile) homes.
• This water heater is suitable for combi-
nation water heating and space heating
and not suitable for space heating appli-
cations 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, or the Natural Gas and
Propane Installation Code, CSA B149.1.
If installed in a manufactured home, the
installation must conform with the Manu-
factured Home Construction and Safety
Standard, Title 24 CFR, Part 3280 and/
or CAN/SCA Z240 MH Series, Mobile
Homes.
• 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, or the Canadian Electri-
cal Code, CSA C22.1.
• The appliance and its main gas valve
must be disconnected from the gas sup-
ply piping system during any pressure
testing of that system at test pressures
in excess of 1/2 psi (3.5 kPa) (13.84 in
Wc). For system testing at pressures
less than or equal to 1/2 psi (3.5 kPa)
(13.84 in Wc) the appliance must be iso-
lated from the gas supply piping by clos-
ing its individual manual shuto valve.
• You must follow the installation instruc-
tions 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 backow preventer in the cold
water supply line, means shall be provid-
ed 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 o, turn o the manual
gas control valve to the appliance.
(En cas de surchaue ou si l’alimen-
tation en gaz ne s’arrête pas, fermez
manuellement le robinet d’arrêt de l’ad-
mission de gaz.)
• Combustion air must be free of chem-
icals, such as chlorine or bleach, that
produce fumes. These fumes can dam-
age components and reduce the life of
your appliance.
Topics in this section
• Installation Guidelines
• What you will need
• Choose Installation Location
• Mount Water Heater to the Wall
• Vent Water Heater
• Connect Water Supply
• Install Isolation Valves
• Install Pressure Relief Valve
• Connect Condensate Drain
• Connect Gas Supply
• Connect Power Supply
• Congure Parameter Settings
• Connect External Pump with Circ-Logic
• Post-Installation Checklist
18 Rinnai Tankless Water Heater Installation and Operation Manual
DO NOT
• DO NOT install the following internal
(indoor) water heaters outdoor: RSC199i
and RSC160i.
• DO NOT install the following exter-
nal (outdoor) water heaters indoor:
RSC199e and RSC160e.
• 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 oors of the structure. When such
locations cannot be avoided, it is recom-
mended that a suitable drain pan, ade-
quately drained, be installed under the
water heater. The pan must not restrict
combustion air ow.
• DO NOT install the water heater in an
area with negative air pressure.
• DO NOT obstruct the ow 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.
4.2 What You Will
Need
4.2.1 Items Included
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.
• Rinnai Tankless Water Heater
• Wall Mounting Bracket (for internal/in-
door water heaters only)
• Pressure Relief Valve and Adapter
• Isolation Valve Kit (for quick isolation
of the water heater for service and/or
maintenance)
• Thermal Isolation Valve
• Literature Bag
– Tankless Water Heater Installation
and Operation Manual (this manual)
– Wall Mounting Bracket Template (for
internal/indoor water heaters only)
– Model/Serial Number Labels (with
printed QR code)
• Vent screens (x2) and vent screen
screws (x2) (for internal/indoor water
heaters only). The vent screen prevents
debris and other objects from entering
the terminal. One vent screen is for the
intake; the other is for the exhaust.
• Self-Tapping Screws (x2) (for internal/
indoor water heaters only)
4.2.2 Items Needed
(Field-Supplied)
• Pipe wrenches (x2)
• Phillips Head screwdriver
• Wire Cutters
• Gloves
• Safety glasses
• Level
• Soap or gas leak detector solution
• Approved venting
• Teon tape (recommended) or pipe
compound
• Pipe insulation
• 3/4 in. Tee (For Dedicated Return)
• 3/4 in. Check Valve (For Dedicated
Return)
• 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
• Heat tape
• Electrical wire
• Concrete wall anchors
• Optional pipe cover
• PVC glue/cement and primer
• 2 conductor 22 AWG wire for controller
• Union and drain valves
• Single gang electrical box
• Wire nuts
• Unions and drain valves
Rinnai Tankless Water Heater Installation and Operation Manual 19
4.3 Choose an
Installation
Location
When selecting an installation location, you
must ensure that clearances will be met and
that the vent length will be within required
limits. Consider the installation environment,
water quality, and 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.
4.3.1 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 general guidelines 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 qualied professional
to ensure the water does not contain corrosive
chemicals or elements that can aect or damage
the Rinnai Tankless Water Heater. Water that
contains chemicals exceeding the levels 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 ushing schedule.
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 ush
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 oers Southeastern Filtration’s
“ScaleCutter Water Conditioning System”
that oers superior lime scale prevention and
corrosion control.
4.3.2 Environment
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 beauty shops, dry
cleaning stores, photo processing labs, and
storage areas for pool supplies often contains
these compounds. Therefore, it is recommended
that external (outdoor) models be used for
these locations where possible. In applications
utilizing room air where there are high levels of
particulates, Rinnai oers 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.
*Source: Part 143 National Secondary Drinking Water
Regulation
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
Table 5: Water Quality Guidelines
20 Rinnai Tankless Water Heater Installation and Operation Manual
4.3.3 Internal (Indoor) Water
Heaters
• Install the water heater as far away as
possible from any air inlet vents. Corro-
sive 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 internal (indoor)
and external (outdoor) water heater.
• 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 combustion air might be contami-
nated with chemicals.
• DO NOT use room air in applications
where the indoor air is corrosive. In-
stall 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 as far away as
possible from any air inlet vents. Corro-
sive 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 internal (indoor)
and external (outdoor) water heaters.
4.3.4 External Water
Heaters and Vent
Terminations
• Install the water heater as far away as
possible from exhaust vent hoods and
dryer vents.
• 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.
• Damage and repair due to corrosive
compounds in the air is not covered by
warranty.
• Install the water heater as far away as
possible from any air inlet vents. Corro-
sive 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 internal (indoor)
and external (outdoor) water heaters.
Rinnai Tankless Water Heater Installation and Operation Manual 21
4.3.5 Freeze Protection
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 gas and 120-volt power supply, the water heater will not freeze when the outside
air temperature is as cold as -22°F (-30°C) for internal (indoor) models or -4°F (-20°C) for external
(outdoor) models, when protected from direct wind exposure. Because of the “wind-chill” eect, 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 that will enable the water heater to immediately drain upon loss of power
(the condensate trap and pressure relief valve are not aected by the Drain Down Kit and must be
manually drained).
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.
Route Drain Per Local Code
Cold Water
Supply Line
1/2 in. Normally Open Solenoid Valve
Hot Water
Supply Line
3/4 in. Normally Closed Solenoid Valve
Legend
Vacuum Breaker
Pressure Relief Valve
Union
Check Valve
Ball Valve
Solenoid Valve
Drain Valve
Freeze Protection Piping Diagram
Vacuum Breaker *
Vacuum Breaker
Drain Valve
Pressure Relief Valve
Union
Check Valve
Ball Valve
Solenoid Valve
1/2 in. Normally Open Solenoid Valve
Route Drain Per Local Code
Cold Water Supply LineHot Water
Supply
Line
3/4 in. Normally Closed Solenoid Valve
Vacuum Breaker
Freeze Protection Piping Diagram
Figure 7: Freeze Protection Piping Diagram
22 Rinnai Tankless Water Heater Installation and Operation Manual
4.3.6 Clearances
Location
Clearances 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
(Internal/Indoor Models)
0 in.
Front Exhaust
(External/Outdoor Models)
24 in. (610 mm)
Side
Top Top
Side
Bottom
Bottom
FrontFront
Figure 8: Clearances
Table 6: Clearances
Internal (Indoor) Models External (Outdoor) Models
Rinnai Tankless Water Heater Installation and Operation Manual 23
4.3.7 Installation Location Checklist
Use this checklist to ensure you have selected the correct location for the water heater.
□
The water heater is not exposed to corrosive compounds in the air.
□
The water heater location complies with the required clearances.
□
The planned combustion 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 (for internal/indoor
models) 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 Fuel Gas Code, ANSI Z221.3/NFPA 54, or the Natural Gas and Propane
Installation Code, CSA B149.1
24 Rinnai Tankless Water Heater Installation and Operation Manual
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.
4.4 Mount the Water Heater to the Wall
4.4.1 Mount the Internal
(Indoor) Water Heater
You Will Need:
• Rinnai Tankless Water Heater
(Internal/Indoor Model)
• Wall Mounting Bracket
Supplied by Installer:
• Level
• 4 Screws for mounting bracket installa-
tion
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 installation requires
the water heater to be level.
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 11: Mount the top bracket
Figure 9: Level the bracket
Figure 10: Secure the bracket
Rinnai Tankless Water Heater Installation and Operation Manual 25
4. Securely screw the top and bottom brackets
into the wall, making sure the screws are
ush with the wall.
• Use any of the holes in the top and bot-
tom brackets.
• Make sure the securing method is su-
cient to support the weight of the water
heater. Refer to the water heater weight
in section “3.4 Specications.”
Top Bracket
Bottom
Bracket
4.4.2 Mount the External
(Outdoor) Water
Heater to the Wall
You Will Need:
• Rinnai Tankless Water Heater
(External/Outdoor Model)
Supplied by Installer:
• Level
• Screws for top and bottom bracket instal-
lation
Use appropriate screws for type of wall
construction.
Instructions:
1. Securely screw the top and bottom brackets
into the wall, making sure the screws are
ush with the wall.
• Use any of the holes in the top and bot-
tom brackets.
• Use a level (placed horizontally or ver-
tically) to make sure the water heater is
straight. Proper operation requires the
water heater to be level.
• Make sure the securing method is su-
cient to support the weight of the water
heater. Refer to the water heater weight
in section “3.4 Specications.”
Figure 12: Mount the bottom bracket
Figure 13: Mount the water heater
The water heater must be installed in an
upright position. Do not install the water
heater upside down or on its side.
IMPORTANT
The water heater must be installed in an
upright position. Do not install the water
heater upside down or on its side.
IMPORTANT
26 Rinnai Tankless Water Heater Installation and Operation Manual
4.5 Vent the Water Heater
4.5.1 Guidelines
• Internal water heaters can be installed
as direct vent or non-direct vent applica-
tions.
• When installed as Direct Vent, refer to
the “Direct Vent Approved Vent Manufac-
turers and Products” section (within sec-
tion “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 schedule 40 PVC when ac-
cepted by local codes.
• Exhaust must be directly vented to the
outside. Combustion 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 according to the
National Fuel Gas Code, ANSI Z223.1/
NFPA 54.
• 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 ttings.
• For manufactured vent systems, vent
connections must be rmly pressed
together so that the connections form an
air tight seal. Follow the venting manu-
facturer’s instructions.
• Refer to the PVC/CPVC manufacturer
for appropriate ttings, solvents or join-
ing methods.
• The vent piece connected to the water
heater must be secured with 1 self-tap-
ping screw.
• Refer to the instructions of the vent sys-
tem manufacturer for component assem-
bly 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
qualied professional or the local inspec-
tor.
• Any issues resulting from improper vent
installation will not be covered by warranty.
• DO NOT use cellular core PVC/CPVC.
• DO NOT use Radel or galvanized material
to vent this appliance.
• DO NOT cover non-metallic vent pipe and
ttings with thermal insulation.
• DO NOT combine vent components from
dierent manufacturers.
• DO NOT reduce the vent diameter. 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 certied
common vent system.
WARNING
Rinnai Tankless Water Heater Installation and Operation Manual 27
4.5.2 Venting Installation
Sequence
1. Install the water heater.
2. Determine the 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 air and vent piping from water heater
to termination.
6. Slope horizontal exhaust run towards the
water heater 1/4 in. per foot. DO NOT slope
combustion air pipe towards water heater.
7. Install vent supports and brackets allowing
for movement from expansion, or as per
vent manufacturer’s instructions or local
code requirements.
8. Install vent screen (supplied with water
heater) on PVC combustion air and exhaust
termination elbows as illustrated below.
• Press vent screen inside of termina-
tion piece/elbow.
• Secure vent screen to the elbow with
screw provided.
4.5.3 Termination
Considerations
Check to determine whether local codes
supersede the following clearances:
• Avoid termination locations near a dryer
vent.
• Avoid termination locations near com-
mercial cooking exhaust.
• Avoid termination locations near any air
inlets.
• You must install a vent termination at
least 12 in. above the ground or antici-
pated snow level.
The vent for this appliance shall not terminate:
• Over public walkways.
• Near sot 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 sot
(ventilated or unventilated or eave vent; or to a
deck or porch):
• Do not install vent termination under a
sot vent such that exhaust can enter
the sot 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 sot where it could
present recirculation of exhaust gases
back into the combustion air part of the
termination.
Figure 14: Vent Screen
28 Rinnai Tankless Water Heater Installation and Operation Manual
4.5.4 Venting Options
Three types of venting options are available:
1. Direct Vent (Concentric Pipe and Twin Pipe)
2. Non-Direct Vent (Room Air and External)
3. Common Vent (Indoor Unit Only. Direct Vent and Non/Direct/Room Air Vent)
Concentric Pipe
Combustion air and exhaust
vent directly through a single
concentric connection. Hot
exhaust exits through the interior
tube, while combustion air enters
through the outer layer.
Twin Pipe
Combustion air and
exhaust vent directly
through separate
penetrations.
Room Air
Room air is used for combustion
while exhaust vents to the
outside.
External (Outdoor)
External (outdoor) water
heater.
Direct Vent
Multiple water heaters sharing a combustion
air 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.
Figure 15: Concentric Pipe
Figure 16: Twin Pipe
Figure 17: Room Air
Figure 18: External
Figure 20: Common Vent, Room Air
Figure 19: Common Vent, Direct Vent
Rinnai Tankless Water Heater Installation and Operation Manual 29
1. Direct Vent (Concentric Pipe and Twin Pipe)
Direct Vent Approved Vent Manufacturers and Products
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.
Manufacturer Phone Web Site
Ubbink 800-621-9419 www.rinnai.us
Centrotherm 877-434-3432 www.centrotherm.us.com
Heat-Fab 800-772-0739 www.heatfab.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
Manufacturer
Manufacturer
Part number
Product
Description
Diagram
Horizontal
Vertical
Equivalent
Length (ft)
2 in. /4 in. CONCENTRIC VENT TERMINATIONS
UBBINK
US/Canada
229031/229012NPP
229032/229013NPP
2/4 Condensing Horizontal Termination Kit 12 in.
2/4 Condensing Horizontal Termination Kit 21 in.
5
224359/224356NPP
2/4 Condensing Roof Discharge Termination 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
IPEX
1906005, 197040
FGV Concentric Vent Kit (16 in. length) 20
1906005PVC
(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)
Table 7: Approved Vent Manufacturers
Table 8: Approved Vent Products
30 Rinnai Tankless Water Heater Installation and Operation Manual
1. Direct Vent (Concentric Pipe and Twin Pipe)
Manufacturer
Manufacturer
Part number
Product
Description
Diagram
Horizontal
Vertical
Equivalent
Length (ft)
2 in. /4 in. CONCENTRIC VENT TERMINATIONS (continued)
ROYAL
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
CENTROTHERM
ICRT2439 2 in. x 4 in. Concentric Roof Termination 20
DURAVENT
2PPS-VKL/VK-TCL
2 in. x 4 in. Vertical Termination Cap-Kit
Concentric
20
2PPS-HKL
2 in. x 4 in. Horizontal Termination
Kit-Concentric
20
ECCO
190288 2 in. x 4 in. Concentric Horizontal
Termination
5
190295 2 in. x 4 in. Concentric Vertical
Termination
5
DIVERSITECH
CVENT-2
2 in. Concentric Vent (Termination) 20
Rinnai Tankless Water Heater Installation and Operation Manual 31
1. Direct Vent (Concentric Pipe and Twin Pipe)
Manufacturer
Manufacturer
Part number
Product
Description
Diagram
Horizontal
Vertical
Equivalent
Length (ft)
3 in. /5 in. CONCENTRIC VENT TERMINATIONS
UBBINK
223174PP
223176PP
223177PP
3/5 Condensing Horizontal Termination Kit 12 in.
3/5 Condensing Horizontal Termination Kit 21 in.
5
223186PP
3/5 Condensing Horizontal Diverter Termination
Kit 19 in.
16
224047PP
3/5 Condensing Raised Horizontal Termination
Kit
24
184162PP
3/5 Condensing Roof Discharge Termination 20
in. above roof
5
IPEX
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)
ROYAL
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
HEAT-FAB
SC03HT
Horizontal Termination Adapter
20
SC03VT
Vertical Termination Adapter
20
CENTRO
THERM
ICRT3539
3 in./5 in. Concentric Roof Termination PPs-UV
20
32 Rinnai Tankless Water Heater Installation and Operation Manual
1. Direct Vent (Concentric Pipe and Twin Pipe)
Manufacturer
Manufacturer
Part number
Product
Description
Diagram
Horizontal
Vertical
Equivalent
Length (ft)
3 in. /5 in. CONCENTRIC VENT TERMINATIONS (Continued)
METAL-FAB
3CGRLSV Vertical Adapter 1
3CGRLSH Horizontal Adapter 6
3CGRVT Vertical Termination 5
3CGRHT
3 in. x 5 in. Vertical Termination Cap Kit-
Concentric
16
DURAVENT
3PPS-VKL/VK-TCL
3 in. x 5 in. Vertical Termination Cap Kit-
Concentric
20
3PPS-HKL
3 in. x 5 in. Horizontal Termination Kit-
Concentric
20
ECCO
190388
3 in. x 5 in. Concentric
Horizontal Termination
5
190395 3 in. x 5 in. Concentric Vertical Termination 5
DIVERSITECH
CVENT-3 3 in. Concentric Vent (Termination) 20
Rinnai Tankless Water Heater Installation and Operation Manual 33
1. Direct Vent (Concentric Pipe and Twin Pipe)
Manufacturer
Manufacturer
Part number
Product
Description
Diagram
Horizontal
Vertical
Equivalent
Length (ft)
2 in. TWIN PIPE TERMINATIONS
CENTROTHERM
ISELL0287UV 2 in. 87° Long PPS-UV 6
ISTT0220 2 in. Termination Tee 6
ISLPT0202 2 in. Low Prole Wall Termination 5
DURAVENT
2PPS-HTPL 2 in. Twin Pipe Termination 10
2PPS-HSTL 2 in. Single Horizontal Termination 6
2PPS-TBL 2 in. Black UV Resistant Tee 5
IPEX
196984
FGV PVC Low Prole Termination Kit 5
196984PVC
(Order from Rinnai)
081216 FGV PVC Wall Termination Kit 16
ROYAL
52SWVKGVS6502 PVC Side Wall Vent Kits 5
52WTVKGVS6502 PVC Wall Vent Kits 16
DIVERSITECH
HVENT-2 2 in. Low Prole Horizontal Vent Kit 5
34 Rinnai Tankless Water Heater Installation and Operation Manual
1. Direct Vent (Concentric Pipe and Twin Pipe)
Manufacturer
Manufacturer
Part number
Product
Description
Diagram
Horizontal
Vertical
Equivalent
Length (ft)
3 in. TWIN PIPE TERMINATIONS
CENTROTHERM
ISELL0387UV 3 in. 87° Long PPS-UV 6
ISTT0320 3 in. Termination Tee 6
ISLPT0303 3 in. Low Prole Wall Termination 5
DURAVENT
3PPS-HTPL 3 in. Twin Pipe Termination 10
3PPS-HSTL 3 in. Single Horizontal Termination 5
3PPS-TBL 3 in. Black UV Resistant Tee 6
IPEX
196985
FGV PVC Low Prole Termination Kit 5
196985PVC
(Order from Rinnai)
081219 FGV PVC Wall Termination Kit 16
ROYAL
52SWVKGVS6503 PVC Side Wall Vent Kits 5
52WTVKGVS6503 PVC Wall Vent Kits 16
DIVERSITECH
HVENT-3 3 in. Low Prole Horizontal Vent Kit 5
Rinnai Tankless Water Heater Installation and Operation Manual 35
Approved PVC/CPVC Vent and Air Piping Material
Item Material
Standard for Installation in North America
United States Canada
Thermoplastic Piping Materials
Vent or Combustion Air
Intake Pipe and Fittings
PVC Schedule 40 ANSI/ASTM D1785
Thermoplastic vent pipe
must be certied 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
ABS SCH 40 DWV ASTM-D2661 or CSA B181.1 NOT PERMITTED
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
ttings, 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 Metal
Metal Fab Metal
IPEX PVC/CPVC
DuraVent Polypropylene
Royal PVC
ECCO Manufacturing Polypropylene
DiversiTech PVC/CPVC
Table 11: Approved PVC/CPVC Vent and Air Piping Material
Product
Description
Diagram
Horizontal
Vertical
Equivalent
Length (ft)
Vent Screen N/A
Tee 5
90° Elbow 5
45° Elbow 2.5
Table 9: Various 2 in. or 3 in. Schedule 40 PVC/
CPVC Terminations
Acceptable Acceptable
Not
Acceptable
90° Elbows,
Long Sweep
90° Elbows,
Short Sweep
90° Elbows,
Close Turn
Table 10
36 Rinnai Tankless Water Heater Installation and Operation Manual
4.5.5 Direct Vent (Concentric and Twin Pipe):
Termination Clearances
The information below applies to Concentric and Twin Pipe.
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 sot, located above the terminal within
a horizontal distance of 2 ft (61 cm) from the center line of the terminal
* *
E Clearance to unventilated sot * *
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 (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] *
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 oor..
*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
Clearance in
Ref. A also
applies to
anticipated
snow line
Regulator vent outlet
AIR SUPPLY INLET
VENT TERMINAL
AREA WHERE TERMINAL
IS NOT PERMITTTED
X
V
Clearance in
Ref.
anticipated
snow line
Figure 21: Direct Vent Termination Clearances
Table 13
Notes:
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.
I
If locally adopted installation codes specify clearances dierent than those illustrated, then the most stringent clearance shall prevail.
Rinnai Tankless Water Heater Installation and Operation Manual 37
1. Direct Vent (Concentric Pipe)
Concentric Pipe Overview
Combustion air and exhaust vent directly
through a single concentric connection.
Hot exhaust exits through the interior tube,
while combustion air enters through the
outer layer.
Combustion
air
Exhaust
Combustion
air
Concentric Pipe Termination Clearances
Insi de
Corner
12 in.
(0.30 m)
12 in.
(0.30 m)
60 in. (1.52 m) ver�cally
between terminals
60 in. (1.52 m)
Note: 24 in. (0.61 m)
to wall or parapet
12 in. (0.30 m)
All terminations (horizontal and/or vertical) must terminate 12 in. (0.30 m) above grade or anticipated
snow level.
Figure 23: Concentric Pipe
Figure 24: Between terminals at
dierent levels
Figure 25: Between terminals at same
level
Figure 22: Concentric Pipe Termination Clearances
Corner
38 Rinnai Tankless Water Heater Installation and Operation Manual
Concentric Pipe: Installation
Instructions
1. Remove and discard screw from concentric
ue connection.
2. Remove exhaust adapter ring (discard for
concentric venting congurations.)
3. Install the concentric vent. Ensure it is properly
seated.
4. Secure the vent pipe to the concentric ue
connection with the supplied screw.
Concentric
Vent
Mount Concentric Pipe Through Wall
If venting 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.
Wall Mounting
Bracket Template
Level
Wall Mounting
Bracket
Table 14: Concentric Pipe: Vent Applications
Horizontal Wall Terminations
2 in. x 4 in.
3 in. x 5 in.
Vertical Roof
Terminations
2 in. x 4 in.
and
3 in. x 5 in.
Table 15: Concentric Pipe: Maximum Vent Length
Concentric Vent Maximum Equivalent Length
Vent Sizes 2 in. x 4 in. 3 in. x 5 in.
Vent Lengths 65 ft (20 m) 150 ft (46 m)
• 45° elbow is equivalent to 3 ft (1 m)
• 90° elbow is equivalent to 6 ft (2 m)
Figure 26
Figure 27
Figure 28
Figure 29
Figure 30
Install the venting termination according to the
diagrams and instructions in this manual. Slope
the venting 1/4 in. per foot toward the appliance
according to the vent manufacturer’s installation
instructions. Dispose of condensate per local
codes.
IMPORTANT
Rinnai Tankless Water Heater Installation and Operation Manual 39
1. Direct Vent (Twin Pipe)
Twin Pipe Overview
Combustion air and exhaust vent directly through separate penetrations.
Twin Pipe Termination Clearances
Exhaust
12 in. (0.30 m)
minimum above
combustion air
opening
12 in. (0.30 m)
minimum
12 in. (0.30 m)
minimum
Combustion
Air
12 in. (0.30 m) above
grade or anticipated
snow level
Roof
Indicates area in which intake cannot be installed.
Intake
60 in.
min
12 in.
min
12 in.
min
12 in.
min
12 in.
min
12 in.
min
Intake
Exhaust
Figure 31
Figure 32: Twin Pipe Vertical
Termination of Multiple Water Heaters
Figure 33: Horizontal Vent and Combustion
Air Piping
Minimum clearance for
Ground/Grade/Snow Level
40 Rinnai Tankless Water Heater Installation and Operation Manual
1. Direct Vent (Twin Pipe)
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
combustion air and exhaust.
1. Remove and discard the screw from the
combustion air vent connection.
2. Remove and discard the combustion air vent
cap.
3. Install the combustion air vent pipe. Ensure it
is properly seated.
Secure the combustion air vent pipe to the
combustion air vent connection with the
supplied screw.
4. Install the exhaust vent pipe. Ensure it is
properly seated.
Secure the exhaust vent pipe to the exhaust
adapter ring with the supplied screw.
Combustion Air Vent Pipe
Supplied screw
Exhaust Vent Pipe
DO NOT apply
PVC glues,
solvents, or cleaners to the water heater’s
combustion air or exhaust gasket
connections. Failure to correctly assemble
the components according to these
instructions may result in property
damage, personal injury, or death.
Supplied screw
Figure 34
Figure 35
Figure 36
Figure 37
WARNING
Rinnai Tankless Water Heater Installation and Operation Manual 41
This conguration requires the use of a Concentric Vent
Termination
2 in. or 3 in. PVC/
CPVC IPEX/ Royal
Concentric Side Wall
Termination Conguration
This conguration requires the use of a Concentric Vent
Termination
2 in. or 3 in. PVC/CPVC
IPEX/ Royal Concentric Vertical
Termination Conguration
2 in. or 3 in. Schedule
40 PVC/CPVC or ABS Snorkel
Termination Conguration
2 in. or 3 in. Schedule 40
PVC/CPVC or ABS Standard
upside down “U” Vertical
Termination Conguration
2 in. or 3 in. Schedule
40 PVC/CPVC or ABS Elbow
or Tee Side Wall
Termination Conguration
2 in. or 3 in. Schedule
40 PVC/CPVC or ABS Tee
Vertical Termination
Conguration
2 in. or 3 in. PVC
Low Prole Termination
Conguration
Exhaust and
combustion air
MUST NOT be
brought together
into a single
PVC pipe using
a pipe tting.
1. Direct Vent (Twin Pipe)
Twin Pipe Example Vent Applications
Slope horizontal exhaust 1/4 in. per foot towards the water heater. DO NOT slope combustion air pipe
towards the water heater.
Single
Pipe
Combustion
Air
Exhaust
Twin Pipe Maximum Vent Length
Table 17: Twin Pipe Maximum Equivalent Length
Vent Sizes 2 in. (51 mm) 3 in. (76 mm)
Vent Lengths 65 ft (20 m) 150 ft (46 m)
• 45° elbow is equivalent to 3 ft (1 m)
• 90° elbow is equivalent to 6 ft (2 m)
Table 16
WARNING
42 Rinnai Tankless Water Heater Installation and Operation Manual
2. Non-Direct Vent (Room Air and External)
Room Air and External Termination Clearances
Canadian Installations
1
(CSA B149.1)
U.S. Installations
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 sot, located above the terminal within
a horizontal distance of 2 ft (61 cm) from the center line of the terminal
* *
E Clearance to unventilated sot * *
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 non-mechanical 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] *
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 oor.
*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
Clearance in
Ref. A also
applies to
anticipated
snow line
Regulator vent outlet
AIR SUPPLY INLET
VENT TERMINAL
AREA WHERE TERMINAL
IS NOT PERMITTTED
X
V
Clearance in
Ref.
anticipated
snow line
Figure 38: Room Air and External Termination Clearances
Notes:
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.
Table 18
I
If locally adopted installation codes specify clearances dierent than those illustrated, then the most stringent clearance shall prevail.
Rinnai Tankless Water Heater Installation and Operation Manual 43
Termination Clearances for External (Outdoor) Water Heaters
36 in. (0.91 m) to ventilated or unventilated
sot or eve vent; or to a deck or porch
60 in. (1.52 m) vertically between terminals
2 in.
12 in.
(0.30 m)
Corner
Exhaust Termination Clearances for Internal (Indoor) Room Air Applications
60 in. (1.52 m) vertically between terminals
12 in.
12 in.
(0.30 m)
Corner
Figure 39
Figure 40
• Installation of Non-Direct Vent (Room Air) must use listed category IV venting.
• All terminations (horizontal and/or vertical) must terminate 12 in. above grade or anticipated
snow level.
NOTE
44 Rinnai Tankless Water Heater Installation and Operation Manual
Combustion air must be free of corrosive chemicals. Do not provide combustion air from
corrosive environment. Appliance failure due to corrosive air is not covered by warranty.
IMPORTANT
Room Air: Combustion Air
This water heater requires adequate combustion air for ventilation
and dilution of ue gases. Failure to provide adequate combustion
air can result in unit failure, re, explosion, serious bodily injury or death. Use the following
methods to ensure adequate combustion air is available for correct and safe operation of
this water heater.
For applications containing corrosive indoor air, this appliance must be installed as direct vent. DO
NOT use room air in applications where combustion air contains acid forming chemicals such as
sulfur, uorine and chlorine. These chemicals have been found to cause rapid damage and decay and
can become toxic when used as combustion air in 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.
Unconned Space
An unconned space is dened 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
unconned space.” If the “unconned 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 conned space.
Conned Space
A conned space is dened 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 conned space must have two combustion air openings. Size the combustion air
openings based on the BTU input for all gas utilization equipment in the space and the method by
which combustion 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). Combustion
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 conned 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
conned 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 mm²/kW) of total input rating of all appliances in the
conned space.
WARNING
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.
NOTE
Rinnai Tankless Water Heater Installation and Operation Manual 45
□
Verify all combustion air opening sizes are correct.
□
Ensure that the Combustion Air Requirements are followed that will provide sucient
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 41
Location
To maintain proper circulation of combustion air two
permanent openings (one upper, one lower) must be
positioned in conned spaces. The upper shall be within 12
in. (0.30 m) of the top of the conned space and the lower
opening shall be within 12 in. (0.30 m) of the bottom of the
conned space. Openings must be positioned as to never
be obstructed.
12 in.
(300 mm)
10 in.
(250 mm)
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).
TO PREVENT POSSIBLE PERSONAL INJURY OR DEATH DUE TO AS-
PHYXIATION, COMMON VENTING WITH OTHER MANUFACTURER’S
INDUCED DRAFT APPLIANCES IS NOT ALLOWED.
Checklist for Combustion Air and Venting Requirements
WARNING
Louvers and Grills
Adequate combustion 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 41: Wood: 10 in. x 12 in. x 0.25 = 30 in.
2
Metal: 10 in. x 12 in. x 0.75 = 90 in.
2
46 Rinnai Tankless Water Heater Installation and Operation Manual
Vent Screen
Elbow
Supplied screw
Supplied
screw
Combustion Air Vent Pipe
Exhaust Vent Pipe
Supplied screw
Room Air: Installation Instructions
1. Remove and discard screw from combustion
air vent connection (Figure 42).
2. Remove and discard the combustion air vent
cap
(Figure 43).
3. Install the combustion air vent pipe. Ensure
it is properly seated.
Secure the combustion air vent pipe to the
combustion air vent connection with the
supplied screw (Figure 44).
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
(Figure 45).
Note:
• 2 in vent screen supplied with water
heater.
• Room air screen is available as an
accessory.
5. Install the exhaust vent pipe. Ensure it is
properly seated.
Secure the exhaust vent pipe to the exhaust
adapter ring with the supplied screw (Figure
46).
Figure 42
Figure 43
Figure 44
Figure 45
Figure 46
Rinnai Tankless Water Heater Installation and Operation Manual 47
Room Air: Example Vent Applications
2 in. or 3 in. Schedule
40 PVC/CPVC or ABS
Snorkel Termination
Conguration
2 in. or 3 in. Schedule 40
PVC/CPVC or ABS
Standard Upside Down
“U” Vertical Termination
Conguration
2 in. or 3 in. Schedule 40
PVC/CPVC or ABS Elbow
or Tee Side Wall
Termination
Conguration
2 in. or 3 in. Schedule 40
PVC/CPVC or ABS Tee
Vertical Termination
Conguration
Slope horizontal exhaust 1/4 in. per foot towards
the water heater.
Ubbink exible venting
approved for vertical
non-direct vent (room
air) applications only.
Refer to the ex vent
manual for further
details.
PP Flex Venting
B-Vent Pipe
4 in. (102 mm)
Table 20: Room Air Maximum Equivalent Length
Vent Sizes 2 in. (51 mm) 3 in. (76 mm) 2 in. (51 mm) Ubbink Flex
Vent Length 65 ft (20 m) 150 ft (46 m) 50 ft. (15 m)
• 45° elbow is equivalent to 3 ft (1 m)
• 90° elbow is equivalent to 6 ft (2 m)
Room Air: Maximum Vent Length
Table 19
48 Rinnai Tankless Water Heater Installation and Operation Manual
Room Air: Manufactured (Mobile) Home
For Installation in a Manufactured Home (Mobile Home)
Roof Termination
Roof Flashing
Top and Bottom
Mounting Brackets
PVC Elbow with
Vent Screen
Condensate Drain
Pressure Relief Valve
Hot Water Outlet
Door
Gas Supply
Cold Water Inlet
Louvered Opening
6 in. (152 mm) Maximum
Figure 48: Pipe Connections on
Bottom of Water Heater
To Suitable Drain
Figure 47: Installation Enclosure with Louvered Door for
Manufactured Home Applications
• 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 mount-
ing brackets on the back side of
the water heater.
Model Input
Btu/h
Minimum
Required Area
Example Opening
Size (LxH)
RSC199i 199,000
200 in
2
(0.129 m
2
)
20 in. x 10 in.
(508 mm x 254 mm)
RSC160i 160,000
160 in
2
(0.103 m
2
)
16 in. x 10 in.
(406 mm x 254 mm)
Use the following chart to identify the minimum required size of
the opening in the access door.
Table 21
Rinnai Tankless Water Heater Installation and Operation Manual 49
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.
Do not common vent this water heater with any other water
heater or appliance.
Note: Multiple RSC models (water heaters with a
recirculation pump) cannot be electronically connected
using the EZConnect™ cable. The EZConnect™ cable
connects only an RSC model with an RU model. See
illustration below.
Vent Length
Figure 49: Sample Inline, Freestanding
Conguration
Water Heater Model
# Water
Heaters
Max System Btu/hr
Vent Diameter
3 in. 4 in. 6 in.
RSC199i: REU-NP3237FF-US(A)
and RU199i: REU-N3237FF-US
2 398,000
65 ft
(20 m)
150 ft
(46 m)
150 ft
(46 m)
RSC160i: REU-NP2530FF-US(A)
and RU160i: REU-N2530FF-US
2 320,000
90 ft
(27 m)
150 ft
(46 m)
150 ft
(46 m)
Table 22: Common Vent Maximum Vent Length
Header
Common Vent Maximum Equivalent Vent Lengths
Common vent equivalent lengths include polypropylene
pipe (PP) or PVC in a back-to-back or inline
conguration.
For the table below:
• Header is the main vent pipe into which sev-
eral 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.
RSC199
(With Pump)
Primary
RU199
(Without Pump)
Secondary
RSC199
(With Pump)
RSC199
(With Pump)
CORRECT
NOT CORRECT
Figure 50
Figure 51
Figure 52
50 Rinnai Tankless Water Heater Installation and Operation Manual
4.6 Connect Water Supply
4.6.1 Guidelines
• 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 lter 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.
4.6.2 Instructions
To connect the water supply, follow the instructions 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 t within the connements
of the pipe cover.
y
y
ly
Eq m
Incl
s, B v ,
Valv
P re Relief Valve.)
c
B
Pressure Relief Valve
3/4" Ball Valve
3/4" Union
Check Valve
S
Pressure Regulator
Circulating Pump
Solenoid Valve
Boiler Drain Valve
KEY
This is not an engineered drawing. It is intended only as a guide and not
as a replacement for professionally engineered project drawings.
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
fficials before installation.
y
y
ly
Eq m
Incl
s, B v ,
Valv
P re Relief Valve.)
c
B
Pressure Relief Valve
4" Ball Valve
Check lve
Pressure Regula
c lating Pump
Valve
Boiler Drain Va v
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.
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.
PIPING DIAGRAM FOR BASIC INSTALLATION
Figure 53
y
y
ly
Eq m
Incl
s, B v ,
Valv
P re Relief Valve.)
c
B
Pressure Relief Valve
3/4" Ball Valve
3/4" Union
Check Valve
S
Pressure Regulator
Circulating Pump
Solenoid Valve
Boiler Drain Valve
KEY
This is not an engineered drawing. It is intended only as a guide and not
as a replacement for professionally engineered project drawings.
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
fficials before installation.
y
y
ly
Eq m
Incl
s, B v ,
Valv
P re Relief Valve.)
c
B
Pressure Relief Valve
4" Ball Valve
Check lve
Pressure Regula
c lating Pump
Valve
Boiler Drain Va v
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.
Condensate
Drain Line
Hot Water Supply Line
Cold Water Supply Line
Gas Supply
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.
IMPORTANT
Rinnai Tankless Water Heater Installation and Operation Manual 51
4.7 Install the Isolation Valves
Isolation valves (included with water heater) provide the ability to isolate the water heater from the
structure’s plumbing and allow quick and easy access to ush the heat exchanger. The supplied
isolation valves meet American National Standard (ANSI Z21.10.3) / Canadian Standard (CSA 4.3)
and are ANSI/NSF 61 approved for potable water.
4.7.1 Instructions
1. Position the Hot Isolation Valve (Red) below the Hot Outlet side of the water heater.
2. Hand tighten the Swivel Nut of the Hot Isolation Valve (Red) to the Hot Outlet side of the water
heater.
3. Rotate the Drain Valve to an accessible position. With a wrench, tighten the Swivel Nut to the
water heater.
4. Repeat steps 1-3 for the Cold Isolation Valve (Blue).
5. Connect the Cold Isolation Valve (Blue) to the Cold Water Supply Line.
6. Connect the Hot Isolation Valve (Red) to the Hot Water Supply Line.
7. Ensure that both Drain Valves are in the closed position before turning on water supply.
Figure 54
Hot Outlet
Cold Inlet
Swivel Nut (Integrated Gasket)
Drain Valve
Hot Isolation Valve
(Red)
Cold Isolation Valve
(Blue)
52 Rinnai Tankless Water Heater Installation and Operation Manual
4.8 Install Pressure Relief Valve
Water discharged from the pressure relief valve could cause severe
burns instantly or death from scalds.
4.8.1 Guidelines
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 and
Automatic Gas Shuto Devices for Hot
Water Supply Systems ANSI Z21.22
and /or the standard Temperature,
Pressure, Temperature and Pressure
Relief Valves and Vacuum Relief
Valves, CAN1-4.4.
• 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 man-
ually 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.
• The discharge end of the line shall be
plain (unthreaded) and a minimum of
3/4 in. nominal pipe diameter. The dis-
charge line material must be suitable
for water at least 180° Fahrenheit.
• The pressure relief valve is assembled
to the pressure relief valve adapter as
illustrated on the next page. DO NOT
place any other valve or shut o device
between the pressure relief valve and
the water heater.
• If a pressure relief valve discharges peri-
odically, this may be due to thermal expan-
sion in a closed water supply system. Con-
tact 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 ow 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 ttings or other
restrictions in the relief line. The pressure
relief line should allow for complete drain-
age of the valve and the line.
• DO NOT place any other valve or shuto
device between the pressure relief valve
and the water heater.
WARNING
Rinnai Tankless Water Heater Installation and Operation Manual 53
4.8.2 Instructions
To install the pressure relief valve, follow the steps below.
1. On the bottom of the tankless water heater, hand tighten the Pressure Relief Valve Assembly
and Gasket to the Pressure Relief Valve Union Fitting.
2. Rotate the Pressure Relief Valve Assembly to the desired accessible position. With a wrench,
tighten the Union Nut to the Pressure Relief Valve Union Fitting.
Pressure Relief Valve
Union Fitting
Gasket
Union Nut
Pressure Relief Valve Assembly
The Pressure Relief Valve
Assembly can rotate 360°
to accommodate the
application.
Figure 55
• Do not use pipe dope or thread sealant on union tting with gasket.
• Be careful not to lose or throw away the gasket.
IMPORTANT
54 Rinnai Tankless Water Heater Installation and Operation Manual
4.9 Connect Condensate Drain
4.9.1 Guidelines
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 dis-
posed 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 tem-
peratures should be wrapped with an
approved supplemental heat source.
Install per manufacturer’s instructions.
• Slope the condensate drain lines to-
ward the inside oor drain or conden-
sate 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 oor drain is not available or the
drain is above the level of the conden-
sate drain, a condensate pump should
be installed.
Pipe open to
atmosphere
Pipe submerged
in water
CORRECT NOT CORRECT
Water
Level
Water
Level
• A condensate neutralizer kit is available
from Rinnai. The kit allows condensate to
ow 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.
• The condensate trap will automatically
prime (self-prime) during operation of the
water heater as condensate forms. Con-
densate draining from the water heater
indicates that the trap is full and that there
is no blockage in the condensate drain. It is
not necessary to add water to the conden-
sate trap.
• 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.
Neutralizer
Refer to neutralizer
Installation Manual
and local codes for
neutralizer installation
guidelines.
Pipe open to
atmosphere
Condensate
Pump
Pipe open to
atmosphere
Figure 56
Figure 57
Rinnai Tankless Water Heater Installation and Operation Manual 55
4.9.2 Instructions
To connect the condensate drain pipe:
1. Apply thread sealant to 1/2 in. MNPT
condensate drain port.
2. Thread 1/2 in. NPT tting onto condensate
drain port.
3. Follow the steps in the next section:
“Condensate Pump Safety Switch Wiring.”
4.9.3 Condensate Pump
Safety Switch Wiring
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.”
1/2 in. MNPT
Condensate Drain
To Condensate Pump
Safety Switch
Strip insulation
o both ends
of wire
Cut o crimp
connectors
3. Cut crimp connectors o white wires and
strip the insulation o of the two ends.
4. Select an appropriate length of wire (18
AWG or greater) and strip the insulation
o 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/O” button on the controller.
Test Operation
1. Test the operation of the shut o switch by
unplugging the condensate pump and lling
the condensate reservoir with water until the
oat switch closes the circuit.
2. Turn on the water heater.
3. The water heater displays diagnostic code
“25.”
4. Plug in the condensate pump in and conrm
condensate is owing out of the reservoir.
5. Turn o the water heater by pressing the
“On/O” button on the controller. Wait ve
seconds then turn the power back on. This
will clear the diagnostic code.
Figure 58
Figure 59
The steps in this section must conform with
local codes and the guidelines established by
the National Electrical Code (NEC).
IMPORTANT
56 Rinnai Tankless Water Heater Installation and Operation Manual
NC
NO
COM
To Condensate Pump
Safety Switch
Tankless Water Heater
To Condensate Pump
Safety Switch Wires
Wire Nut Connecting
Two Wires
Field-Supplied Wires
Safety Switch Wires*
Condensate Pump (eld-supplied)
Includes 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)
Condensate Pump Safety Switch Installation
Figure 60
Rinnai Tankless Water Heater Installation and Operation Manual 57
4.10 Connect the Gas Supply
Figure 61
• A trained and qualied professional must
install the gas supply.
• Turn o 120V power supply.
• Turn o the gas.
• Gas is ammable. 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.
4.10.1 Instructions
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 o 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
Specications” 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
nonammable 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.)
WARNING
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 liqueed petroleum gas (propane/
LPG).
7. The gas supply line shall be gas tight, sized,
and so installed as to provide a supply of
gas sucient to meet the maximum demand
of the 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
58 Rinnai Tankless Water Heater Installation and Operation Manual
4.10.2 Gas Pipe Sizing Reference Tables
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 nd 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.
Table 23: Gas Pipe Sizing Calculation
Worksheet
Instructions: Enter values in empty boxes.
Rinnai Model Gas Input:
Additional Appliance Total Gas Input:
Heating Value of Gas:
Cubic Feet Per Hour (CFH):
Answer:
A Btu/hr
B Btu/hr
C Btu/ft
3
(CFH) =
A + B
C
(CFH) =
(CFH) =
ft
3
/hr
Natural Gas
Table 24: Pressure Drop 0.5 in. wc
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) 172 360 678 1,390
20 (6) 118 247 466 957
30 (9) 95 199 374 768
40 (12) 81 170 320 657
50 (15) 72 151 284 583
60 (18) 65 137 257 528
70 (21) 60 126 237 486
80 (24) 56 117 220 452
90 (27) 52 110 207 424
100 (30) 50 104 195 400
Schedule 40 Metallic Pipe
Inlet Pressure: Less than 2 psi
Specic Gravity: 0.60
Table 25: Example
Rinnai Model Gas Input:
Additional Appliance Total Gas Input:
Heating Value of Gas:
Cubic Feet Per Hour (CFH):
Answer:
For this example, the pipe diameter
must be at least 3/4 in. pipe size and
10 ft (3 m) in length.
A
199,000
Btu/hr
B
65,000
Btu/hr
C
1,000
Btu/ft
3
(CFH) =
A + B
C
(CFH) =
199,000+65,000
1,000
(CFH) =
264
ft
3
/hr
Rinnai Tankless Water Heater Installation and Operation Manual 59
Table 26: Pressure Drop 3.0 in. wc
Intended use: Initial supply
pressure of 8.0 in. wc
or greater.
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
40 (12) 214 448 844 1,730
50 (15) 190 397 748 1,540
60 (18) 172 360 678 1,390
70 (21) 158 331 624 1,280
80 (24) 147 308 580 1,190
90 (27) 138 289 544 1,120
100 (30) 131 273 514 1,060
Natural Gas
Table 27: Example
Rinnai Model Gas Input:
Additional Appliance Total Gas Input:
Heating Value of Gas:
Cubic Feet Per Hour (CFH):
Answer:
For this example, the pipe diameter
must be at least 1/2 in. pipe size and
20 ft (6 m) in length.
A
199,000
Btu/hr
B
65,000
Btu/hr
C
1,000
Btu/ft
3
(CFH) =
A + B
C
(CFH) =
199,000+65,000
1,000
(CFH) =
264
ft
3
/hr
Schedule 40 Metallic Pipe
Inlet Pressure: Less than 2 psi
Specic Gravity: 0.60
Propane (Undiluted)
Table 28: Pressure Drop 0.5 in. wc
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 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
Schedule 40 Metallic Pipe
Inlet Pressure: 11 in wc
Specic Gravity: 1.50
Table 29: Example
Rinnai Model Gas Input:
Additional Appliance Total Gas Input:
Total Gas Input:
Answer:
For this example, the pipe diameter
must be at least 1/2 in. nominal pipe
size and 10 ft (3 m) in length.
A
199,000
Btu/hr
B
65,000
Btu/hr
Total Gas
Input
=
264,000
Btu/hr
Total Gas
Input
=
A + B
Total Gas
Input
=
199,000 + 65,000
60 Rinnai Tankless Water Heater Installation and Operation Manual
4.11 Connect the Power Supply
• 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 ordinanc-
es 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.
4.11.1 Guidelines
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 pro-
vided inside the water heater.
• The water heater requires 120 VAC, 60 Hz power from a properly grounded circuit.
• If using the 5 ft (1.5 m) power cord (supplied with internal/indoor water heaters), plug it into a
standard 3 prong 120 VAC, 60 Hz properly grounded wall outlet.
• On external (outdoor) models, a disconnect switch must be provided and 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 and exible cords
must use an appropriate strain relief.
• The wiring diagram is located on the inside of the water heater front cover.
WARNING
120V Wiring
• White wire (Neutral)
• Black wire (Hot leg)
□
Conrm that the electricity is supplied from 120 VAC, 60 Hz power source and is in a properly
grounded circuit.
□
Conrm that an extension cord or an adapter plug has NOT been used with the water heater.
Post-Power Supply Connection Checklist
Ground connection
screw
Disconnect switch (required on external outdoor models)
Figure 62
Rinnai Tankless Water Heater Installation and Operation Manual 61
4.12 Configure Parameter Settings
4.12.1 Instructions
DO NOT adjust parameter settings unless specically instructed to do so.
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 right side of unit).
2. Locate the two push buttons (A and B) on the PC Board.
3. Press the “A” button for 1 second.
WARNING
A
B
4. Use the ▲ (Up) and ▼ (Down) buttons on the controller to select a
setting number (see Parameter Settings Table below).
5. Once the desired setting number is selected, use
the “On/O” 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
below).
6. To exit the parameters, press the “A” button for 1
second.
01A
01B
Figure 63
Figure 64
Figure 65
62 Rinnai Tankless Water Heater Installation and Operation Manual
SETTING #
SETTING
DESCRIPTION
SELECTION
a
c
01
Maximum Set
Temperature
120°F 140°F
02
High Altitude
Installation Location
0 - 2,000 ft
(0 - 610 m)
2 , 0 0 1 - 5 , 4 0 0 f t
(610 - 1,646 m)
5,401 - 7,700 ft
(1,646 - 2,347 m)
7,701 - 10,200 ft
(2,347 - 3,109 m)
03
Service Soon
1
Disabled 0.5 Year 1 Year 2 Years
04
Recirculation Settings
No
Recirculation
Recirculation
(Dedicated)
Recirculation
(Crossover)
05
Recirculation Mode
2
Economy Comfort Commercial
5
07
Units in Standby
(EZConnect™)
2 1
10
Gas Type
(Factory Set)
NG LPG
11
Maximum Flow Rate
4
Standard High
12
Water Heater Model
(Factory set values and
not adjustable)
Without Pump With Pump(RUR) With Pump(RSC)
13
199 (3237) 180 (2934) 160 (2530) 130 (2024)
14
Internal
(Indoor)
External
(Outdoor)
15
6
Low Activation Mode On O
16 Pump Speed Max Low
17*
First Day Pump
Operation
Pump O Pump On
Table 30: Parameter Settings
Default is A for all settings below except 10, 12, 13, and 14 which are factory set.
1
See section “4.12.2 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
BMS = Building Management System
4
Selecting “High” will increase the water ow rate to the maximum capacity.
5
Commercial mode should not be used for residential applications. Application of commercial mode may result in excessive machine
wear and energy consumption.
6
Low Activation Mode must be in the ON position (15a) if crossover recirculation is selected (Parameter 04C).
*For the rst 24-hours of operation, Smart-Circ will learn hot water usage patterns and operate pump based on the learned patterns. On
the rst day, when the tankless water heater has no learned patterns, the unit can be set to no pump operation (Pump O/No Recirc) for
the rst 24 hours or to the pump operating (Pump On/Recirc) every 15 to 30 minutes for the rst 24 hours.
4.12.2 Service Indicator (Service Soon, SS)
5 TIM ES
55
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 ush and
service the water heater.
• Selection is installers preference based on water
conditions or other factors that may inuence 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 dis-
play, contact your local service provider to ush and
service the water heater (see 6.3 Flushing the Heat
Exchanger)
• Service Soon will appear again based on the select-
ed service interval.
To reset Service Soon (55)
Press the ON/OFF button 5 times
NOTE: Service Soon (55) will display
on the controller again when the water
heater reaches the interval selected in the
parameter settings.
Figure 66
Rinnai Tankless Water Heater Installation and Operation Manual 63
4.13 Post-Water Heater Installation Checklist
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 veried 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 sucient 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 veried the vent system does not exceed maximum length?
□ □
PLUMBING YES NO
Have the water lines been purged of all debris and the lter cleaned?
□ □
Have you veried 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 veried 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 the isolation valves (included with the tankless water heater) installed?
□ □
PRESSURE RELIEF VALVE (PRV) YES NO
Does the PRV comply with the standard for Relief Valves and Automatic Gas Shuto
Devices for Hot Water Supply Systems ANSI Z21.22, and/or the standard Temperature,
Pressure, Temperature and Pressure Relief Valves and Vacuum Relief Valves, CAN1-4.4?
□ □
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 water?
□ □
Did you take measures to protect the PRV and PRV discharge line from freezing?
□ □
4
3
2
5
1
64 Rinnai Tankless Water Heater Installation and Operation Manual
Have you veried the PRV is not plumbed with the condensate drain line?
□ □
Have you veried the PRV is not plugged and that reducing ttings, valves, or other
restrictions are not installed in the relief line?
□ □
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 the “Condensate Pump Safety Switch
Wiring” section of the manual.
□ □
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 oor pump is not available or the drain is above the level of the condensate drain, did
you install a condensate pump?
□ □
Have you veried the condensate drain line is not plumbed with the pressure relief valve?
□ □
Have you conrmed the condensate drain line is not connected with an air conditioning
evaporator coil drain?
□ □
Have you veried an external condensate trap is not installed? (This tankless water heater
has an integrated condensate trap.)
□ □
Have you conrmed 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?
□ □
RECIRCULATION PUMP SE+ Series Featuring THERMACIRC360™ Models
Only (RSC199i/e and RSC160i/e)
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 crossover valve installation?
□ □
(Crossover Mode Only) Was the crossover valve installed at the furthest xture from the
water heater?
□ □
6
7
8
AVERTISSEMENT
WARNING
Rinnai Tankless Water Heater Installation and Operation Manual 65
5. 5. OperationOperation
Topics in this section
• Safety Precautions
• Start-up Information
• Control Panel
• Basic Operation Settings
• Diagnostic Codes
5.1 Safety
Precautions
If the information in these instructions is
not followed exactly, a re or explosion may
result causing property damage, personal
injury, or death.
• Do not store or use gasoline or other
ammable 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 oor because some gas is
heavier than air and will settle on the
oor.
• 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 re department.
• Installation and service must be per-
formed by a trained and qualied
professional, service agency or the gas
supplier.
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.
• Ne pas entreposer ni utiliser d’essence
ou ni d’autres vapeurs ou liquides inam-
mables 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 qualié ou par le fournisseur
de gaz.
66 Rinnai Tankless Water Heater Installation and Operation Manual
• Keep the area around the appliance
clear and free from combustible ma-
terials, gasoline, and other ammable
vapors and liquids.
• Do not use this appliance if any part
has been under water. Immediately call
a trained and qualied 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 com-
mande qui ont été plongés dans l’eau.)
• Should overheating occur or the gas
supply fail to shut o, turn o the manual
gas control valve to the appliance.
(En cas de surchaue ou si l’alimen-
tation en gaz ne s’arrête pas, fermez
manuellement le robinet d’arrêt de l’ad-
mission 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 qual-
ied professional. Force or attempted
repair may result in a re 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 exchang-
er ushed regularly. Rinnai provides
a “Scale Control System” that oers
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 loca-
tion free of chemicals, such as chlorine
or bleach, that produce fumes. These
fumes can damage components and
reduce the life of your appliance. Dam-
age 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 specically instructed to do so.
Rinnai Tankless Water Heater Installation and Operation Manual 67
5.2 Operating Instructions
FOR YOUR SAFETY READ BEFORE OPERATING
If you do not follow these instructions exactly, a re or explosion
may result causing property damage, personal injury or loss of life.
OPERATING INSTRUCTIONS
1. STOP! Read the safety information above.
2. Set the temperature controller to lowest setting.
3. Turn o 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 ve (5) minutes to clear out any gas.
Then smell for gas, including near the oor. 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 O Gas To Appliance” and
call your service technician or gas supplier.
TURN OFF GAS TO APPLIANCE
1. Set the temperature controller to lowest setting.
2. Turn o 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.
WARNING
A. This appliance does not have a pilot. It is
equipped with an ignition device which automat-
ically 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 oor because some gas is heavier than air
and will settle on the oor.
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 re 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 qualied service technician.
Force or attempted repair may result in a re or
explosion.
D. Do not use this appliance if any part has been
under water. Immediately call a qualied ser-
vice technician to inspect the appliance and to
replace any part of the control system and any
gas control which has been under water.
Figure 68
Figure 69
5.3.3 In Use Light
The integrated controller “In Use” light ashes
based on the operation status of the water heater
and integrated pump.
Solid Light
Indicates ignition
and water ow.
Slow Flash
Indicates ignition
and pump
operation.
Rapid Flash
Indicates pump
operation with no
ignition.
Figure 70
68 Rinnai Tankless Water Heater Installation and Operation Manual
Display
Increases hot water temperature
Decreases hot water temperature
Indicates the water heater is in use
Enables controller when multiple
controllers are used
Turns the water heater on or o
5.3 Control Panel
The controller panel allows you to adjust the
water temperature, lock the controller on a set
temperature, and view diagnostic information.
5.3.1 Setting the Controller
to Mute
To eliminate the beeps when keys are pressed,
press and hold both the (Up) and (Down)
buttons 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.
5.3.2 Locking the Controller
1. To lock the internal controller, press and
hold down the “Priority” button.
2. While holding down the “Priority” button,
press the (Up) button until a beep is
heard (approximately 5 seconds). Then,
release both buttons at the same time.
3.
appears in the display indicating the
controller is locked.
To unlock the controller, follow the above steps.
The display ashes between and the set
temperature to indicate the controller is locked.
NOTE
Figure 67
Table 31
Figure 71
Rinnai Tankless Water Heater Installation and Operation Manual 69
5.4 Setting the
Temperature
This water heater requires a minimum ow
rate to operate. This rate can be found on the
specication 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 ow being below or close to
the minimum ow rate. Increasing the ow 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 xture.
Water temperatures over 125°F (52°C) can
cause severe burns or scalding resulting in
death.
Hot water can cause rst 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.
The controller buttons shown below are located
on the outside front panel for internal (indoor)
water heaters.
For external (outdoor) water heaters, open the
front panel to access the controller buttons.
1. If the water heater is o, press the “On/O”
button to turn on.
2. The “Priority” button enables a controller if
multiple controllers are being used. If the
“Priority” light is o, then press the “Priority”
button on the temperature controller. The
orange “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) buttons to
obtain the desired temperature setting.
All hot water sources are able to provide
water at this temperature setting until
it is changed again at this or another
temperature controller.
DANGER
• While any hot water is being provided,
the temperature setting can only be
adjusted between 98°F and 110°F.
• Check local codes for the maximum
water temperature setting allowed when
used in nursing homes, schools, day
care centers, and all other public appli-
cations.
• 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 tempera-
ture controller and the temperature at
the tap due to weather conditions or the
length of pipe to the water heater.
IMPORTANT
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
Figure 72
Figure 73
Figure 74
70 Rinnai Tankless Water Heater Installation and Operation Manual
5.4.1 Available Temperatures with an Internal Controller
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/
O” button on the controller for 5 seconds while the water heater is OFF.
* 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 “4.12 Congure Parameter settings” for further details.
* For Crossover Mode, minimum temperature setting is 120°F (49°C).
5.5 Performance Data
To obtain performance data:
1. Press and hold the (Down) button.
2. While holding the (Down) button for 2 seconds, press and hold
the “On/O” button (hold both buttons simultaneously).
3. Use the (Up) and (Down) buttons to scroll to the desired
information described in the Performance Data Table.
4. To exit performance data, repeat step 2 above.
5. When complete, the set temperature appears in the display.
Table 32
Rinnai Tankless Water Heater Installation and Operation Manual 71
# Data Unit
01
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
11
HEX Outlet Temp. °F
12
By-Pass Flow Control Position Degrees of opening
15
Freeze Protection Temperature
(Indoor Units Only)
°F
17
Freeze Protection Temperature
(Outdoor Units Only)
°F
19
Pump Hours x100 Hours
20
Pump Cycles *
21
Exhaust Temperature °F
Table 33: Performance Data Table
* Refer to the Technical Data Sheet located on the inside front cover of the
water heater for additional information.
WARNING
Figure 75
72 Rinnai Tankless Water Heater Installation and Operation Manual
5.6 Diagnostic Codes
To display diagnostic codes:
Turn o the water heater by pressing the “On/O” button.
Press and hold the “On/O” for 2 seconds and then the (Up)
button simultaneously.
The last nine maintenance codes display and ash one after the
other.
To exit diagnostic codes and return the water heater to normal
operation, press and hold the “On/O” button for 2 seconds and
then the (Up) button simultaneously.
Turn on the water heater by pressing the “On/O” button.
Some of the checks below should be performed by a trained and
qualied professional. Consumers should never attempt any action that
they are not qualied to perform.
03
Power interruption during bath ll
(Water will not ow when power returns)
• Turn o all hot water taps. Press ON/
OFF twice.
05
By-Pass Flow Control
• Measure resistance or voltage values
of the by-pass ow control.*
• Replace By-Pass ow control device.
10
Air Supply or Exhaust Blockage/
Condensate Trap is Full
• Ensure condensate line is not blocked.
• Ensure internal air lter is clean with
no obstructions. (Indoor Water Heaters
Only)
• Ensure High Altitude setting. (See
Parameter Settings)
• Ensure Combustion air and Exhaust
vents are not blocked and approved
venting materials are being used.
(Indoor Water Heaters Only)
• Ensure vent length is within limits.
(Indoor Water Heaters Only)
• Check fan for debris and ensure wheel
turns freely.
• Verify check valve is not stuck between
fan casing and burner body.
11
No Ignition (Heater Not Turning On)
• Check that the gas is turned on at the
water heater, meter, or cylinder.
• If the system is propane, make sure
that gas is in the tank.
• Ensure gas type and inlet gas
pressure are correct.
• Bleed all air from gas lines.
• Check the ground wire for the PC
Board.
• Ensure ame rod wire is connected.
• Ensure igniter is operational.*
• Check gas solenoid valves for open or
short circuits.*
• Verify gas orice is correct.
• Ensure condensate line is not blocked.
12
No Flame
• Check that the gas is turned on at the
water heater, gas meter, or cylinder.
• If the system is propane, make sure
that gas is in the tank.
• Ensure ame rod wire is connected.
• Ensure gas type and inlet gas
pressure is correct.
• Bleed all air from gas lines.
14
Heat Exchanger Overheat
• Measure resistance or voltage of
Overheat Switch.*
• Check heat exchanger surface for hot
spots which indicate blockage due to
scale build-up.
• Refer to instructions in manual for
ushing heat exchanger. Hard water
must be treated to prevent scale build
up or damage to the heat exchanger.
• Ensure it is not in forced Hi setting.
* See “Electrical Diagnostics” on Technical Data
Sheet located on inside front cover of water
heater.
Rinnai Tankless Water Heater Installation and Operation Manual 73
* See “Electrical Diagnostics” on Technical Data
Sheet located on inside front cover of water
heater.
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)
• Conrm 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.
• Please call Rinnai technical
department.
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.
25
Condensate Pump (Accessory)
• Conrm 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
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 ame rod and wire for damage.
• Check gas solenoid valve for open or
short circuit.*
• Replace gas valve assembly.
• Please call Rinnai technical
department
54
High Exhaust Gas Temperature
• Ensure Heat Exchanger ns are clean
and not blocked.
• Conrm 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 the inlet water lter is clean
and free of debris.
• Ensure Parameter setting are correctly
set for recirculation mode.
• Ensure Pump supply voltage.
• Ensure air is removed from the
recirculation line.
65
Water Flow Control
• Measure resistance or voltage values
of the water ow control.*
• The water ow control valve has failed
to close during the bath ll function.
Immediately turn o the water and
discontinue the bath ll function.
Contact a trained and qualied
professional to service the appliance.
70
PC Board
• Replace PC Board
If recirculation water temperature is not
adequate, conrm pump speed is set to Max
(Parameter 16a). Recirculation ow rate must be
greater than 0.4 GPM (1.5 L/min).
74 Rinnai Tankless Water Heater Installation and Operation Manual
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.
72
Flame Rod
• Check ame rod and wire for damage.
• Verify HEX is not leaking.
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 (Up) ,
(Down) and On/O simultaneously.
• FF is visible on the monitor.
SS
(SS) Service Soon (Flush Heat
Exchanger)
• SS is a time-based service indicator
set during installation. See section
“4.12 Congure Parameter Settings”
for additional details on setting and
changing the SS indicator.
• SS indicates that it is time for service.
The heat exchanger should be ushed
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.
• To reset the SS code, push the On/O
button on the temperature controller 5
times in 5 seconds.
* See “Electrical Diagnostics” on Technical Data
Sheet located on inside front cover of water
heater.
FF
NO CODE - Nothing happens when
water ow is activated
• Verify you have at least the minimum
ow rate required to re unit.
• Measure the resistance or voltage of
the water ow control sensor.*
• Clean inlet water supply lter.
• On new installations ensure hot and
cold water lines are not reversed.
Visit rinnaipro.myabsorb.com for additional
troubleshooting resources.
Rinnai Tankless Water Heater Installation and Operation Manual 75
5.7 Configuring Recirculation
Figure 78 Figure 79
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 xed recirculation schedule is desired, then installation of an MC-195T-US Timer/controller or
control·r™ Wi-Fi Module is required.
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/ control•r™) is installed.
MC-195T-US Timer/Controller
Wired in digital control with integrated
timer function for recirculation control.
control•r™ Wi-Fi Module
Wired in digital control with integrated
timer function for recirculation control.
Included
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
xture in the plumbing system. Refer to the Crossover Mode section of this manual for additional
details.
NOTE: Thermal Bypass Valve should only be used for Crossover Mode Recirculation systems.
Thermal Bypass Valve
Figure 76
Figure 77
Fixed schedule recirculation for RSC models requires the installation of the control·r™ Wi-Fi Module or
MC-195T-US controller.
1
If the control•r™ Wi-Fi Module or MC-195T-US controller are not installed, temporary pump operation can
be initiated by resetting power to the appliance.
On Demand push buttons and motion sensors require installation of a controller (see section "3.6
Accessories" for part numbers). Visit rinnai.us/wi for more information.
Note: Recirculation parameter setting 04 must be set to your circulation mode. See “Parameter Settings”
section in this document for more information.
1
DO NOT install the control•r™ Wi-Fi Module and MC-195T-US together as they are NOT compatible
accessories.
Cold
Hot
76 Rinnai Tankless Water Heater Installation and Operation Manual
5.7.1 ThermaCirc360™ Recirculation (Determine
Recirculation Mode)
Two recirculation modes are available:
DEDICATED MODE CROSSOVER MODE
Cold Water
Hot Water
Dedicated mode (factory default) - Home
includes a dedicated circulation return line
in the plumbing system. The water heater
is shipped congured 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) at the farthest xture
in the plumbing system.
General Guidelines
• For the licensed installer / professional
• For installation in commercial and resi-
dential 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 (Cas-
cade / EZConnect™) multiple RSC
units together.
• DO NOT install the MC-195T-US Timer/
Controller and control•r™ Wi-Fi Module
together as they are not compatible
accessories.
PRV Connection
Gas Connection
Water drain plug
Cold water inlet with lter
Condensate drain line
Condensate trap drain plug
Hot water outlet
Connection Diagram
Figure 80 Figure 81
Figure 82
Rinnai Tankless Water Heater Installation and Operation Manual 77
5.7.2 ThermaCirc360™ Recirculation (Crossover Mode)
Plumbing Diagram (Crossover Mode)
Gas Supply Line
Cold Water Supply Line
Floor Drain
Condensate Drain Line
Hot Water Fixtures
Hot Water Supply Line
Install thermal isolation valve
at the farthest xture from the
tankless water heater
Figure 83
Figure 84
78 Rinnai Tankless Water Heater Installation and Operation Manual
Parameter Settings
Refer to the parameter setting section of this manual for instructions on how to access and change
parameter settings.
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 o continuously, which may result in excessive machine wear and energy consumption.
Pump Status Typical Intervals
OFF
Economy 10
Comfort 4
Commercial 4
Important: The internal pump
in an RSC model runs based on
time intervals only and not water
temperature (like dedicated return
line recirculation systems)
Table 34
Table 36
SETTING
#
SETTING DESCRIPTION
SELECTION
A C
04
Recirculation Settings No Recirculation
Recirculation
(Dedicated)
Recirculation
(Crossover)
05
Recirculation Mode Economy Comfort
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
Table 35
Table 38: 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)
(*Take equivalent elbow
lengths and all ttings
into consideration when
calculating pipe length.)
Rinnai Tankless Water Heater Installation and Operation Manual 79
5.7.3 ThermaCirc360™ Recirculation (Dedicated Mode)
Plumbing Diagram (Dedicated Mode)
Condensate Drain Line
Floor Drain
Hot Water Supply Line
Hot Water Fixtures
Cold Water Supply Line
Locate Drain
Valve as close
as possible to
the Cold Water
Supply Tee
Gas Supply Line
Dedicated Recirculation Line
Figure 87
Figure 88
80 Rinnai Tankless Water Heater Installation and Operation Manual
Parameter Settings
Refer to the parameter settings section of this manual for instructions on how to access and change
parameter settings.
04 Recirculation Settings
Dedicated 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
Table 38: 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)
(*Take equivalent elbow
lengths into consideration
when calculating pipe
length.)
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 o continuously, which may result in excessive machine wear and energy consumption.
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 39
Table 37
SETTING
#
SETTING DESCRIPTION
SELECTION
A C
04
Recirculation Settings No Recirculation
Recirculation
(Dedicated)
Recirculation
(Crossover)
05
Recirculation Mode Economy Comfort
Rinnai Tankless Water Heater Installation and Operation Manual 81
6. 6. MaintenanceMaintenance
Topics in this section
• Maintenance
• Cleaning and Inspecting the Air Filter
(Indoor Units Only)
• Flushing the Heat Exchanger
• Draining the Water Heater
6.1 Maintenance
This water heater must be inspected annually by
a trained and qualied professional. Repairs and
maintenance shall be performed by a trained and
qualied professional. The trained and qualied
professional must verify proper operation after
servicing.
To protect yourself from harm, before performing
maintenance:
• Turn o the electrical power supply by un-
plugging the power cord or by turning o
the electricity at the circuit breaker. (The
temperature controller does not control the
electrical power.)
• Turn o the gas at the manual gas control
valve, usually located immediately below
the water heater.
• Turn o the incoming water supply. This
can be done at the isolation valve immedi-
ately below the water heater or by turning
o the water supply to the building.
Keep the appliance area clear and free from
combustible materials, gasoline, and other
ammable vapors and liquids.
The following maintenance items are required for
the proper operation of your water heater.
The appliance must be inspected annually by a
trained and qualied professional. Repairs and
maintenance shall be performed by a trained and
qualied professional. The trained and qualied
professional must verify proper operation after
servicing.
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 ame for proper color. Once ignited,
the ame must cover the surface of the burner.
The ame must burn with a clear, blue, stable
ame. If the ame does not have this appearance,
complete the following steps:
1. Turn o and disconnect electrical power. Allow
to cool.
2. Remove the front panel by removing four
screws.
3. Use a vacuum to remove dust from the main
burner and fan blades. Do not use a wet cloth
or spray cleaners on the burner. Do not use
volatile substances such as benzene and
thinners; they may ignite or fade the paint.
4. Use soft dry cloth to wipe cabinet.
CONDENSATE COLLECTION AND
DISPOSAL SYSTEM
Periodic inspection and cleaning of the
condensate collection and disposal system.
Ensure condensate is owing 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 qualied
professional.
WARNING
WARNING
Testing the pressure relief valve should only
be performed by a trained and qualied
professional. Water discharged from the
pressure relief valve could cause severe burns
instantly or death from scalds.
WARNING
FRONT VIEW
Flame Rod
Blue Flame
SATISFACTORY
82 Rinnai Tankless Water Heater Installation and Operation Manual
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 aect or damage the heat exchanger.
Water that contains chemicals exceeding the
levels required aect 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 ue 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 owing 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 lter by
closing the cold and hot water inlet isolation
(shut-o)t valves. Put a bucket under the lter
at the bottom of the water heater to catch
any water that is contained inside the unit.
Unscrew the water lter. Rinse the lter to
remove any debris. Install the lter and open
the isolation valves.
• Air Filter — See section “6.2 Cleaning and
Inspecting the Air Filter” for more information.
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 ow.
Contact with your body or other property may
cause damage or harm.
VISUAL INSPECTION OF FLAME
Verify proper operation after servicing. The burner
must ame evenly over the entire surface when
operating correctly. The ame must burn with a
clear, blue, stable ame. See the parts breakdown
of the burner for the location of the view ports.
The ame pattern should be as shown in the
images below:
Figure 91
UNSATISFACTORY
FRONT VIEW
Flame Rod
Yellow Flame
Rinnai Tankless Water Heater Installation and Operation Manual 83
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 aected 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 eective 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
Gas
Shut o the gas to the water heater. It is generally
preferable to shut o the gas service to the entire
location if gas is not going to be used.
Water
• Shut o the cold water supply to the water
heater. It is generally preferable to shut o
the water to the entire location if water is
not going to be used.
• Drain the water heater by opening the
drain valves on the cold water line and hot
water line.
• Open several hot water taps and remove
the lter assembly at the water inlet in
order to allow room for expansion in case
there is water in the lines that freeze.
Condensate
Drain the condensate using the condensate drain
port on the bottom of the water heater.
Electric
Disconnect the power supply by either unplugging
the electrical cord or by turning o the circuit
breaker to the water heater to prevent potential
damage from irregular power surges or
interruptions.
6.2 Cleaning and
Inspecting the Air
Filter (Indoor Units
Only)
INSPECTION
• To maintain optimum performance,
periodically inspect the air lter.
• If the air lter appears to have lint and/or
dust build up, follow the cleaning
procedure described below.
• If the air lter appears damaged, contact
a trained and qualied professional for a
replacement air lter assembly.
CLEANING
1. Power OFF the water heater
• Push the “On/O” button located on the
right-hand side of the controller. The dis-
play will go blank when the power is o.
Figure 92
84 Rinnai Tankless Water Heater Installation and Operation Manual
2. Remove the front panel.
• Remove the four screws securing the front panel.
• Remove the front panel and locate the lter at the upper right-hand corner of the water heater.
• Remove the air lter 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 lter area of the air lter door.
• With clean water, rinse the soap o the lter.
4. Dry the Air Filter: With a lint free towel, dry the air lter.
5. Inspect and Replace the Air Filter
• Inspect the air lter for any debris that may restrict air ow to the water heater.
• If the lter still appears dirty repeat the cleaning steps.
• Replace the air lter.
6. Power ON the water heater.
Figure 93
Do not operate this water heater if the air lter is not in place.
NOTE
Rinnai Tankless Water Heater Installation and Operation Manual 85
6.3 Flushing the Heat
Exchanger
This water heater includes a service indicated/
reminder (Service Soon, SS). When selected in
the parameter settings, an SS code will display
on the controller indicating that it is time to ush
and service the water heater. Failure to ush
the appliance will cause damage to the heat
exchanger. Damage caused by lime build-up
is not covered by the water heater’s warranty.
Rinnai strongly recommends installation of
isolation valves to allow for ushing of the heat
exchanger.
1. Turn o power at the controller.
2. Disconnect electrical power to the water
heater.
3. Close the shuto valves on both the hot
water and cold water lines (V3 and V4).
4. Connect pump outlet hose (H1) to the cold
water line at service valve (V2).
5. Connect drain hose (H3) to the hot water
line at service valve (V1).
6. Pour four gallons of undiluted virgin, food
grade, white vinegar into pail.
7. Place the drain hose (H3) and the hose (H2)
to the pump inlet into the cleaning solution.
8. Open both service valves (V1 and V2) on
the hot water and cold water lines.
9. 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).
10. Turn o the pump.
11. 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 out-
side to drain.
B. Close service valve (V2) and open shuto
valve (V4). Do not open shuto valve
(V3).
C. Allow water to ow through the water
heater for ve minutes.
D. Close shuto valve (V4). When unit has
nished draining remove the in-line lter
at the cold water inlet and clean out any
residue. Place lter back into unit and
open valve (V4).
E. Close service valve (V1) and open shuto
valve (V3).
12. Disconnect all hose.
13. Restore electrical power to the water heater.
Figure 94
Scale build-up will aect the performance of the
water heater. Water should be treated. Rinnai
oers Southeastern Filtration’s “ScaleCutter
Water Conditioning System” that oers superior
lime scale prevention and corrosion control by
feeding a blend of control compounds into the
cold water supply.
NOTE
Figure 96: Piping Diagram
HOT
COLD
ON!
Cold Drain
Valve
Cold Isolation
Valve
PRV Lever
Hot Isolation
Valve
Hot Drain
Valve
Condensate
Trap Drain Plug
Condensate
HOT
PRV
COLD
86 Rinnai Tankless Water Heater Installation and Operation Manual
6.4 Draining the Water
Heater
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 o.
WARNING
Figure 95
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 o cold water supply and gas supply.
2. Turn o the temperature 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 (only for pump
version).
To resume normal operation:
1. Conrm that the gas supply is turned o, all
taps are closed and PRV lever is closed.
2. Insert the condensate trap drain plug.
3. Close the hot and cold drain valves.
4. Open the cold and hot water isolation valves.
5. Open a tap and conrm that water ows, and
then close.
6. Connect power to the water heater.
7. After conrming that the temperature controller
is o, turn on the gas supply.
8. Turn on the temperature controller.
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 o and
close the gas supply valve.
2. Turn on a hot water tap to ow
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 o
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.
Rinnai Tankless Water Heater Installation and Operation Manual 87
For Gas Models Sold in Massachusetts
NOTICE BEFORE INSTALLATION:
This direct-vent appliance must be installed by a
properly trained and qualied 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 nished grade in the area of the venting,
including but not limited to decks and porches,
the following requirements shall be satised:
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
tter shall observe that a hard-wired carbon
monoxide detector with an alarm and battery
back-up is installed on the oor level where
the gas equipment is to be installed. In
addition, the installing plumber or gas tter
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 qualied professional for the
installation of hard-wired carbon monoxide
detectors.
A. In the event that the side wall, horizon-
tally 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 oor 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 com-
ply with the above requirements; provid-
ed, 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
certied.
3. SIGNAGE. A metal or plastic identication
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.
7. 7. AppendicesAppendices
Topics in this section
• Massachusetts State Gas Regulations
• Wiring Diagram
• Ladder Diagram
• Pressure Drop and Water Flow Curves
• Guidelines for Additional Temperature
Controllers
7.1 Massachusetts State
Gas Regulations
88 Rinnai Tankless Water Heater Installation and Operation Manual
Figure 97
COMBINATION SPACE HEATING/POTABLE WATER SYSTEM
(For Use In Commonwealth of Massachusetts)
Combination Space
Heating/Potable
Water System
All water piping should be
insulated in accordance with
780 CMR (Massachusetts
Energy Code)
Expansion Tank
Check Valve with 1/8in. Hole
Drilled in Clapper Optional
Shut O Valve
Cold Water Supply
Min. 2'
developed
length Type L
copper from
water heater
Product Approved
Water Heater
Check Valve
Automatic Tempering Device Must be installed
below the top of the water heater as per
manufacturer's recommendations.
Tempered water to plumbing xtures. Must
meet temperature requirements of 248 CMR.
Hot Water
Supply and
Return to
Heating Coil
Electronically controlled
pump timer. Activates
every 6 hours for 60
seconds. Wire to product
approved pump. (or built-
in pump)
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.
Hot Water Coil
NSF-61 Product
Approved Pump
Check Valve
Air Handler
System installed with
reverse acting aquastat to
shuto fan. Suggested but
not required by 248 CMR.
Gas Supply
Water Heater
Use Only in Commonwealth of Massachusetts
Rinnai Tankless Water Heater Installation and Operation Manual 89
7.2 Wiring Diagram
PC BOARD
Figure 98
90 Rinnai Tankless Water Heater Installation and Operation Manual
7.3 Ladder Diagram
Figure 99
Rinnai Tankless Water Heater Installation and Operation Manual 91
7.4 Pressure Drop and Water Flow Curves
Pressure Loss (PSI)
Water Flow (GPM)
Presure Loss (ft of Head)
RSC160
RSC199
Dashed lines represent ow rate
after parameter adjustment.
The chart below applies only to incoming water temperatures of 70°F (21°C) or less. For incoming water
temperatures greater than 70°F (21°C), please contact Rinnai.
Delta T - Temperature Rise (°F)
Water Flow (GPM)
NOTE: Maximum ow rates may vary based
on set temperature, Delta T and altitude.
Dashed lines represent ow rate
after parameter adjustment.
RSC199
RSC160
Figure 100
Figure 101
92 Rinnai Tankless Water Heater Installation and Operation Manual
7.5 Pump Performance Curve
Figure 102
Need updated image
from RJ
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
Presure Loss(ft of Head)
Water Flow(GPM)
MAX
LOW
Total Head (ft)
Water Flow (GPM)
Rinnai Tankless Water Heater Installation and Operation Manual 93
7.6 Guidelines for Additional Temperature Controllers
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.
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.
Number of Wired
Controllers
Maximum Cable
Length for Each
Controller to Water
Heater
1 328 ft (100 m)
2 164 ft (50 m)
3 or 4 * 65 ft (20 m)
Four Temperature
Controllers
Connect controller cable to
mating terminal at bottom right
side of PC Board.
Wiring illustration
(Detailed wiring instructions included with
temperature controller package)
* Only three additional controllers can be wired
to the water heater.
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 digi-
tal display may be dicult to read in direct
sunlight.
• Avoid locations where the temperature con-
troller could be splashed with liquids.
• Do not install in locations where the tem-
perature controller can be adjusted by the
public.
MC195T
US Timer/
Controller
OR
control•r™ Wi-Fi
Module
DO NOT install the MC-195T-US Timer/
Controller and control•r™ Wi-Fi Module together
as they are not compatible accessories.
Figure 103
Figure 104
Table 40
SmartCirc™ is not available with the use of
MC195T or control•r.
NOTE
94 Rinnai Tankless Water Heater Installation and Operation Manual
8. 8. WarrantyWarranty
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 qualied 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.
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
[1]
For residential applications, the heat exchanger warranty is 15 years or 12,000 operation hours, whichever occurs rst.
[2]
For commercial applications, the heat exchanger warranty is 8 years or 12,000 operation hours, whichever occurs rst.
Notes:
From date of purchase, period of coverage is reduced to 8 years or 12,000 operation hours, whichever occurs rst, 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 qualied 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 qualied 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 veried 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.
Rinnai Tankless Water Heater Installation and Operation Manual 95
What Is Not Covered?
This Limited Warranty does not cover any failures or operating diculties 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 res, ooding, 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.
Use of an MCC-91-2 controller in a residential dwelling will reduce the warranty coverage to that of
a commercial warranty application except when an MCC-91-2 is used with a hydronic air handler for
temperatures no higher than 160°F (71°C).
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 tness for a particular purpose, which extend beyond the
description of the warranty herein.
Any implied warranties of merchantability and tness 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 prots, 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 specic legal rights, and you may also have other rights which vary from
state to state.
www.rinnai.us/warranty
100000773(01)
1/2023
Place
Model/Serial #
Label Here
Located in Manual Bag
Rinnai America Corporation
103 International Drive
Peachtree City, GA 30269
Tel: 1-800-621-9419
Web: rinnai.us
rinnai.ca
