Installa on Instruc ons and
Use & Care Guide
Standard Condensing
Residen al Gas
Tankless Water Heater
Residen al On-Demand Gas Tankless Water Heater
(X3® TECHNOLOGY available on some models)
100383494_2000838040February 2025
Keep this manual with the heater for future reference whenever maintenance, adjustment or service is required.
Retain your original receipt as proof of purchase.
Read this manual and the labels on the water heater before
you install, operate, or service it. This water heater is designed
for Natural Gas opera on only. If you have diffi culty following
the direc ons, or aren’t sure you can safely and properly do
any of this work yourself:
• Call our Technical Assistance Hotline which is listed on your warranty.
We can help you with installa on, opera ons, troubleshoo ng, or
maintenance. Before you call, write down the model and serial number
from the water heater’s ra ng plate.
• Incorrect installa on, opera on, or service can damage the water
heater, your house and other property, and present risks including fi re,
scalding, electric shock, and explosion, causing serious injury or death.
Do not store or use gasoline or other fl 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 instruc ons.
• If you cannot reach your gas supplier, call the fi re de-
partment.
Installa on and service must be performed by a qualifi ed
installer, service agency or the gas supplier.
WARNING: If the informa on in these instruc ons
is not followed exactly, a fi re or explosion may
result causing property damage, personal injury or
death.
LOW LEAD
C
O
NTENT
MODELS:
TM-160M-N, TM-180M-N, TM-199M-N
TM-160X3-N, TM-180X3-N, TM-199X3-N
NATURAL GAS ONLY
(M MODELS AVAILABLE IN US ONLY)
2 • Residen al Gas Tankless Water Heater Use and Care Guide
TABLE OF CONTENTS
WATER HEATER BASICS ................................................................................................... 4
Component Overview (X3® Model Shown) ................................................................................................................................ 4
Typical InstallaƟ on (X3® Model Shown) ..................................................................................................................................... 5
Dimensions ................................................................................................................................................................................ 6
Supply ConnecƟ ons .................................................................................................................................................................... 7
Product Specifi caƟ on and Technical Data .................................................................................................................................. 8
IMPORTANT SAFETY INFORMATION ............................................................................... 9
RISKS DURING INSTALLATION AND MAINTENANCE ................................................................................................................. 10
RISKS DURING OPERATION ...................................................................................................................................................... 10
GETTING STARTED ........................................................................................................ 12
Read Before InstallaƟ on .......................................................................................................................................................... 12
Included Items ......................................................................................................................................................................... 14
Available Accessories ............................................................................................................................................................... 15
Recommended Tools and Materials ......................................................................................................................................... 16
Recommended Accessories ...................................................................................................................................................... 16
INSTALLATION .............................................................................................................. 17
InstallaƟ on Environment ......................................................................................................................................................... 17
Unit Clearances........................................................................................................................................................................ 17
MounƟ ng the Water Heater .................................................................................................................................................... 17
CombusƟ on and VenƟ ng InstallaƟ on ....................................................................................................................................... 18
CombusƟ on Air Supply OpƟ ons ............................................................................................................................................... 20
VenƟ ng .................................................................................................................................................................................... 21
Installing the Vent Pipe ............................................................................................................................................................ 23
Exhaust Vent for Indoor InstallaƟ on ........................................................................................................................................ 24
Input Rate at Maximum Vent Length ...................................................................................................................................... 24
Typical PDV Confi guraƟ ons:..................................................................................................................................................... 25
Typical PV Confi guraƟ ons: ....................................................................................................................................................... 25
Vent TerminaƟ ons .................................................................................................................................................................... 26
Clearances for Sidewall TerminaƟ ons ...................................................................................................................................... 29
Clearances for RooŌ op TerminaƟ ons ....................................................................................................................................... 31
Exhaust Vent for Outdoor InstallaƟ on ..................................................................................................................................... 34
Residen al Gas Tankless Water Heater Use and Care Guide • 3
TABLE OF CONTENTS
Gas Supply and Gas Pipe Sizing ............................................................................................................................................... 35
Water ConnecƟ ons .................................................................................................................................................................. 37
X3® Technology ........................................................................................................................................................................ 38
Pressure Relief Valve ................................................................................................................................................................ 39
Condensate Drain .................................................................................................................................................................... 40
RecirculaƟ on ............................................................................................................................................................................ 40
Electrical ConnecƟ ons .............................................................................................................................................................. 42
Accessory ConnecƟ ons............................................................................................................................................................. 43
Cascade System ....................................................................................................................................................................... 44
OPERATION .................................................................................................................. 46
FOR YOUR SAFETY, READ BEFORE OPERATING ........................................................................................................................ 46
Start-Up InstrucƟ ons ................................................................................................................................................................ 46
Shut-Down InstrucƟ ons ........................................................................................................................................................... 46
Emergency Shut-Down ............................................................................................................................................................ 46
Display Overview ..................................................................................................................................................................... 48
Temperature Seƫ ngs............................................................................................................................................................... 49
Confi guraƟ on Mode (C Mode) ................................................................................................................................................. 50
Unit Conversion Mode ............................................................................................................................................................. 52
MAINTENANCE ............................................................................................................ 53
Regular Maintenance .............................................................................................................................................................. 53
Freeze ProtecƟ on System ......................................................................................................................................................... 53
Unit Draining & Power Outage (Freeze ProtecƟ on) ................................................................................................................. 54
Discharge Condensate ............................................................................................................................................................. 54
Inlet Water Filter ...................................................................................................................................................................... 54
TROUBLESHOOTING ..................................................................................................... 55
General TroubleshooƟ ng ......................................................................................................................................................... 55
Error Codes .............................................................................................................................................................................. 57
Fault Analysis of Error Codes ................................................................................................................................................... 58
COMPONENT LIST ........................................................................................................ 64
APPENDIX .................................................................................................................... 67
Flow Rate Capacity Chart ........................................................................................................................................................ 67
4 • Residen al Gas Tankless Water Heater Use and Care Guide
WATER HEATER BASICS
Component Overview (X3® Model Shown)
Gas Valve
Printed Circuit Board (PCB)
Gas Manifold
Primary Heat Exchanger
X3
®
Cartridge
Flow Sensor
Control Valve
Assembly
Fan Motor Assembly
Water Bypass Valve
Ignitor &
Flame Rod Assembly
Air Intake
Secondary Heat Exchanger
Flue Gas Exhaust
Burner Assembly
Controller Display
(removed for clarity)
Bypass
Cartridge
(Alternative
Configuration)
X3® Technology (X3® Model):
This water heater is equipped with X3® Scale Preven on Technology to inhibit scale forma on within the heat exchanger tubing of this unit.
Part of the X3® Technology’s an -scale protec on comes from the special X3® Cartridge media. The X3® Cartridge must be installed into the
manifold located on the underside of the heater cabinet prior to opera on of the unit. X3® Scale Preven on Technology reduces the forma on
of scale in the heat exchanger, extending the opera ng life of the unit in typical potable water installa ons. Specifi c water condi ons may
impact the effi ciency of X3®, such as excessive iron or manganese levels. The maximum allowable limit of iron is 0.3 mg/l or 0.3 ppm and
manganese is 0.05 mg/l or 0.05 ppm. Levels greater than these will reduce the eff ec veness of the X3®. Refer to the guidelines below and
consult a water quality expert to determine if your water is within acceptable X3® and EPA guidelines.
NOTICE: Pressure Relief Valve supplied in the box with this model.
Bypass Cartridge (M Model Available in US Only):
The Bypass cartridge will come preinstalled from the factory. Please verify the three screws securing the Bypass cartridge are ghtened.
See page 38.
NOTICE: Pressure Relief Valve will need to be fi eld supplied with this model.
Residen al Gas Tankless Water Heater Use and Care Guide • 5
WATER HEATER BASICS
Typical Installa on (X3® Model Shown)
Water
Shut-off Valve
Expansion
Tan k
Gas
Line
CWS
HWS
Gas
Shut-off Valve
Pressure Relief Valve
(Drain Line not
shown for clarity)
Drip Leg
Flue Gas ExhaustAir Intake
Condensate Drain
(Drain Line not
shown for clarity)
(Hot Water Supply)
(Cold Water Supply)
Water
Shut-off
Valve
6 • Residen al Gas Tankless Water Heater Use and Care Guide
WATER HEATER BASICS
Dimensions
WALL
6.58"
16.72 cm
25.19"
63.98 cm
WATER
HEATER
WALL
MOUNT
12.26"
31.14 cm
2.96"
7.52 cm
28.35"
72.01 cm
5"
12.7 cm
3.56"
9.04 cm
8.56"
21.74 cm
WALL STUDS
0.94"
2.39 cm
17.12"
43.48 cm
11.85"
30.10 cm
40.41"
102.64 cm
4.62"
11.73 cm
32.46"
82.45 cm
3.78"
9.60 cm
Residen al Gas Tankless Water Heater Use and Care Guide • 7
WATER HEATER BASICS
Supply Connec ons
2
1
4
5
WALL
HOT
COLD
GAS
3
Table 1: Supply Connec ons
Item Descrip on Dimensions Connec on Size
1 Cold Inlet 8.89 in/22.58 cm 3/4" MNPT
2 Hot Outlet 5.88 in/14.94 cm 3/4" MNPT
3 Condensate Connec on 5.58 in/14.17 cm 1/2" MNPT
4 Wall Bracket 0.98 in/2.49 cm N/A
5 Gas Inlet 9.72 in/24.69 cm 3/4" MNPT
8 • Residen al Gas Tankless Water Heater Use and Care Guide
WATER HEATER BASICS
Product Specifi ca on and Technical Data
X3® Models: Comes with the X3® Scale Preven on Technology cartridge and pressure relief valve installed.
M Models (Available in US Only): Comes with the Bypass cartridge installed.
Table 2: Specifi ca ons
Model TM-160 TM-180 TM-199
Natural Gas Input
(Minimum Opera ng Range)
BTU/H 10,000
Natural Gas Input
(Maximum Opera ng Range)
BTU/H 160,000 180,000 199,000
Gas Connec on 3/4" NPT
Water Connec ons 3/4" NPT
Water Pressure* psi (MPa) 15 - 150 (0.1 - 1)
Water Flow Rate** gpm (L/min) 0.26 - 10.5 (1.0 - 39.7), Ac va on Min: 0.4 (1.5)
Natural Gas
Inlet Pressure
inch W.C. (kPa)
Min: 4.0 (1.0)
Max: 10.5 (2.62)
Weight lbs (kg) 83 (37.6)
Dimensions
(Including X3®)
inch W 17.12 x H 40.41 x D 11.85
cm W 43.48 x H 102.64 x D 30.10
Igni on Electronic Igni on
Electric Supply 120 V, 60 Hz, <5 A
Water Heater Category*** Category IV
*40 psi or above is recommended for maximum fl ow.
**Minimum ac va on fl ow rate may increase if energy demand required is below the minimum input ra ng of the water heater.
***Water Heater Category - does not apply to Outdoor or Direct Vent installa ons.
Category IV - a water heater that operates with a posi ve vent sta c pressure and with a vent gas temperature that may cause
excessive condensate produc on in the vent.
NOTES:
• Check the ra ng plate to ensure that this product matches your specifi ca ons. This water heater is designed for
Natural Gas only.
• The manufacturer reserves the right to discon nue, or change at any me, specifi ca ons or designs without no ce and with-
out incurring obliga on.
Residen al Gas Tankless Water Heater Use and Care Guide • 9
IMPORTANT SAFETY INFORMATION
Read and follow all safety messages and instruc ons in this
manual.
This is the safety alert symbol. It is used to alert you to
poten al physical injury hazards. Obey all safety messages
that follow this symbol to avoid possible property damage,
serious injury or death. Do not remove any permanent
instruc ons, labels, or the ra ng plate from either the
outside of the water heater or on the inside of the access panels. Keep this
manual near the water heater.
WARNING! If the informa on in these instruc ons is not followed
exactly, a fi re or explosion may result causing property damage, personal
injury or death. Do not store or use gasoline or other fl ammable vapors and
liquids in the vicinity of this or any other appliance.
An odorant is added by the gas supplier to the gas used by this water heater.
This odorant may fade over an extended period of me. Do not depend upon
this odorant as an indica on of leaking gas. We recommend installing a fuel
gas and carbon monoxide detector.
This product is cer fi ed to comply with a maximum weighted average of
0.25% lead content as required in some areas.
DANGER indicates a hazardous
situa on that, if not avoided, will
result in death or serious injury.
WARNING indicates a hazardous
situa on that, if not avoided, could
result in death or serious injury.
CAUTION indicates a hazardous
situa on that, if not avoided, could
result in minor or moderate injury.
NOTICE indicates prac ces not
related to physical injury.
DANGER
WARNING
CAUTION
NOTICE
*Operate the Pressure Relief Valve
annually and inspect Pressure Relief
Valve every 2-4 years (see the label
on the Pressure Relief Valve for
maintenance schedule). If no label
is attached to the Pressure Relief
Valve, follow the instructions in the
Maintenance section of this manual.
See the Regular Maintenance section
for more information about maintaining
this water heater.
Important informa on to keep
Fill out this sec on and keep this manual
in the pocket of the water heater for
reference.
Date Purchased:
Model Number:
Serial number:
Maintenance performed:* Date:
10 • Residen al Gas Tankless Water Heater Use and Care Guide
To reduce the risk of property
damage, serious injury or death, read
and follow the precau ons below,
all labels on the water heater, and
the safety messages and instruc ons
throughout this manual.
RISKS DURING
INSTALLATION AND
MAINTENANCE
Li ing Risk
WARNING! The
water heater is
heavy. Follow these
precau ons to reduce the risk of
property damage, injuries from li ing
or impact injuries from dropping the
water heater.
• Use at least two people to li the
water heater.
• Be sure you both have a good grip
before li ing.
• Use an appliance dolly or hand truck
to move the water heater.
Explosion Risk
WARNING! This water
heater is designed for
Natural Gas opera on only. Refer
to the water heater’s ra ng plate.
Failure to follow these instruc ons
can result in serious injury or death
from explosion, fi re or carbon
monoxide poisoning.
• DO NOT connect this Natural Gas
water heater to an L.P. gas supply.
• Use a new gas supply line approved
for Natural Gas that meets local and
state/provincial codes.
• Install a full port shut-off valve on
the gas supply line.
• Maintain the Pressure Relief Valve
properly. Follow the maintenance
instruc ons provided by the manu-
facturer of the Pressure Relief Valve
(label a ached to Pressure Relief
Valve). If no label is a ached to the
Pressure Relief Valve, follow the
instruc ons in the Pressure Relief
Valve Maintenance sec on of this
manual. An explosion could occur if
the Pressure Relief Valve or dis-
charge pipe is blocked. Do not cap
or plug the Pressure Relief Valve or
discharge pipe.
Gas Pressure
WARNING! The Natural Gas
supply pressure must not exceed the
maximum supply pressure as stated
on the water heater’s ra ng plate.
Have a qualifi ed person (licensed
plumber, gas company personnel,
or authorized service technician)
check for proper gas pressure. Gas
pressures exceeding the maximum
supply pressure as stated on the
water heater’s ra ng plate can
result in serious injury or death from
explosion or fi re.
RISKS DURING
OPERATION
Scalding Risk
This water heater
can make water hot
enough to cause
severe burns instantly, resul ng in
severe injury or death.
• Feel water before bathing or show-
ering.
• To reduce the risk of scalding, install
Thermosta c Mixing Valves (tem-
perature limi ng valves) at each
point-of-use. These valves automa -
cally mix hot and cold water to limit
the temperature at the tap. Mixing
valves are available at your local
plumbing supplier. Follow the man-
ufacturer’s instruc ons for installa-
on and adjustment of the valves.
• Water temperatures over 125°F
(52°C) can cause severe burns
instantly or death from scalding. The
water temperature is set at 120°F
(49°C) from the factory to minimize
any scalding risk. Before bathing or
showering, always check the water
temperature. Higher temperatures
increase the risk of scalding, but even
at 120°F, hot water can scald. If you
choose a higher temperature se ng,
Thermosta c Mixing Valves located
at each point-of-use are par cularly
important to help avoid scalding.
Table 3: Scalding Table
Temperature
Time to Produce a
Serious Burn
120°F (49°C) More than 5 minutes
125°F (52°C) 1½ to 2 minutes
130°F (54°C) About 30 seconds
135°F (57°C) About 10 seconds
140°F (60°C) Less than 5 seconds
145°F (63°C) Less than 3 seconds
150°F (66°C) About 1½ seconds
155°F (68°C) About 1 second
For more informa on about changing
the factory temperature se ng, refer
to the “Temperature Se ngs” sec on
in this manual.
• Water temperature will be ho er if
someone adjusted the set tempera-
ture to a higher se ng.
• Should overhea ng occur or the
burner fail to shut off , turn off the
manual gas supply valve to the
water heater and call a qualifi ed
person.
IMPORTANT SAFETY INFORMATION
Residen al Gas Tankless Water Heater Use and Care Guide • 11
IMPORTANT SAFETY INFORMATION
To reduce the risk of unusually hot
water reaching the fi xtures in the
house, install Thermosta c Mixing
Valves at each point-of-use.
If anyone in your home is at par cular
risk of scalding (for example, the
elderly, children, or people with
disabili es) or if there is a local code
or state/provincial law requiring a
certain water temperature at the
hot water tap, these precau ons are
par cularly important.
According to a na onal standard
American Society of Sanitary
Engineering (ASSE 1070) and most
local plumbing codes, the water
heater’s thermostat should not be
used as the sole means to regulate
water temperature and avoid scalds.
Water Contamina on Risk
Do not use chemicals that could
contaminate the potable water supply.
Do not use piping that has been
treated with chromates, boiler seal, or
other chemicals. Suitable for potable
water hea ng only.
Fire Risk
To reduce the risk of a
fi re that could result in
property damage, or serious injury or
death:
• Do not store things that can burn
easily such as paper or clothes next
to the water heater.
• Do not store or use gasoline or other
fl ammable substances in the vicinity
of this or any other appliance.
• Do not use this appliance if any part
has been in contact with or been im-
mersed in water. Immediately call a
qualifi ed installer or service agency
to replace a fl ooded water heater.
Do not a empt to repair the unit. It
must be replaced.
Explosion Risk
High pressures in the
water heater can cause
an explosion resul ng in property
damage, serious injury or death. A
Pressure Relief Valve is required to
be installed on the water heater.
A Pressure Relief Valve is supplied
with X3® models and shall be fi eld
supplied for M models. Addi onal
pressure protec ve equipment may
be required by local codes.
A na onally recognized tes ng
laboratory maintains public inspec on
of the valve produc on process
and cer fi es that it meets the
requirements for Relief Valves for Hot
Water Supply Systems, ANSI Z21.22.
The Pressure Relief Valve’s relief
pressure must not exceed the working
pressure ra ng of the water heater as
stated on the ra ng plate.
Carbon Monoxide Risk
WARNING! This
water heater
operates by burning
gas. Carbon
monoxide is a
colorless, odorless,
gas that is a by-product of burning of
fuels such as coal, wood, charcoal,
oil, kerosene, propane, and natural
gas. Breathing excessive and
abnormal amounts of carbon
monoxide can cause carbon
monoxide poisoning, resul ng in
serious injury or death. This water
heater must be supplied with
adequate combus on air and must
be properly vented to the outdoors.
Have a qualifi ed person (licensed
plumber, authorized gas company
personnel, or authorized service
technician) install the ven ng system
using these installa on instruc ons.
Install a fuel gas and carbon
monoxide detector in the living areas
of your home.
Failure to follow these instruc ons
can result in serious injury or death
from carbon monoxide poisoning.
12 • Residen al Gas Tankless Water Heater Use and Care Guide
Read Before
Installa on
1
Review all of the instruc ons
before you begin work.
Improper installa on can
damage the water heater, your home
and other property, and can present
risks of serious injury or death.
2
This water heater is designed
as a Category IV, posi ve
vented sta c pressure water
heater (vent gas temperatures may
cause excessive condensate
produc on in the vent), which takes
its combus on air either from the
installa on area or from air ducted to
the unit from the outside. This water
heater must be installed:
• Following all local codes, or in the
absence of local codes, follow the
current edi on of ANSI Z223.1/NFPA
54, Na onal Fuel Gas Code in the
USA or B149.1, Natural Gas and Pro-
pane Installa on Code in Canada.
• For installa on in manufactured
homes (mobile homes) follow the
current edi on of The Manufactured
Home Construc on and Safety Stan-
dard, Title 24 CFR, Part 3280 and/or
CSA Z240 MH Series, Manufactured
Homes.
• Follow the electrical code require-
ments of the local authority having
jurisdic on. In the absence of such
requirements, follow the current
edi on of the Na onal Electrical
Code ANSI/NFPA 70 in the USA or
the current edi on of CSA C22.1
Canadian Electrical Code Part 1 in
Canada.
This is available from the following:
CSA Group, Inc.
United States:
8501 East Pleasant Valley Road
Cleveland, OH 44131
Canada:
178 Rexdale Blvd.
Toronto, ON
Canada M9W 1R3
Na onal Fire Protec on Associa on
1 Ba erymarch Park
Quincy, MA 02269
Check with local code offi cials about
codes governing this installa on.
Have your installa on inspected by a
code offi cial to ensure the installa on
meets all local codes.
NOTICE: Installa on and service must
be performed by a qualifi ed installer
(for example, a licensed plumber or
gas fi er). Otherwise, the warranty
will not apply. The installer (licensed
professional) is responsible for the
correct installa on of the water
heater and for compliance with all
na onal, state/provincial, and local
codes.
Massachuse s code requires this
water heater to be installed in
accordance with Massachuse s
248-CMR 2.00 and 248-CMR 5.00:
State Plumbing Code. Other local
and state authori es may have
similar requirements or other codes
applicable to the installa on of this
water heater.
3
Before you start, be sure to
check the following:
WARNING! Do not store or use
fl ammable materials, vapors, or
liquids in the same loca on where
this water heater is installed.
• All gas water heaters require correct
installa on to ensure safe and effi -
cient opera on. This manual must
be followed exactly. Read the en re
manual before installa on and re-
view the "Important Safety Informa-
on" sec on (see page 9).
• Carefully plan the installa on loca-
on of the heater and vent termina-
ons.
• The water heater must be installed
where the proper amount of
combus on air will be available to
it at all mes without obstruc ons.
When installed indoors, the water
heater can be direct vented.
• The length of piping between the
water heater and fi xture determines
the me it takes for the hot water
to arrive. Consider installing the
water heater closer to fi xtures if
the plumbing system allows for it.
The water heater should be the fi rst
appliance to access the water line
a er the u lity water meter.
• Locate your water heater close to a
drain where water leakage will not
do damage to surrounding areas. As
with any water hea ng appliance,
the poten al for leakage at some
me in the life of the product does
exist. A drain pan, or other means of
protec on against water damage, is
recommended to be installed under
the water heater in case of leaks
to lessen the chance of sustaining
property damage. In addi on, you
may install an ac ve water leak
detector with a shutoff valve which
can turn off the water supply in the
event of a leak. The manufacturer is
not responsible for damage due to
water leaks.
• The water heater shall be securely
wall-mounted or mounted on a
stand.
• Maintain proper space for servic-
ing. Install the unit so that it can be
connected or removed easily. Refer
to the "Unit Clearances" sec on for
proper clearances (see page 17).
NOTICE: For outdoor installa ons,
locate the water heater in an open,
un-roofed area. Maintain 3 inches
(76 mm) minimum clearance from the
le and right sides of the unit.
• The manufacturer does not recom-
mend installing the water heater
in an a c due to safety issues. See
the installa on sec on for further
informa on.
• Failure to observe these warnings
could result in severe personal inju-
ry, death, and/or property damage.
GETTING STARTED
Residen al Gas Tankless Water Heater Use and Care Guide • 13
GETTING STARTED
Ven ng/Combus on
• DO NOT install the water heater
where water, debris or fl ammable
vapors may get into the fl ue termi-
nal. This may cause damage to the
water heater and the warranty will
not apply.
• DO NOT locate your heater in a pit
or loca on where gas and water can
accumulate.
• DO NOT install the unit where the
exhaust vent is poin ng into any
opening in a building or where the
noise may disturb your neighbors.
Make sure the vent termina on
meets the required clearance from
any doorway or opening to prevent
exhaust from entering a building.
Check local code requirements prior
to installa on.
• DO NOT install the exhaust vent for
indoor and outdoor models within
3 feet (914 mm) of an overhang.
Vent termina on must be at least
2 (610 mm) away from an inside
corner for both outdoor installa on
and direct-vent installa on.
Outside
corner
Inside
corner
3
min.
2
min.
2
min.
Overhang
Figure 1 - Overhang and Inside Corner Restric-
ons
• DO NOT install next to a dryer or
any source of airborne debris that
can be trapped inside the combus-
on chamber unless the system is
direct vented. When direct vented,
do not install the air intake near the
dryer vent or any source of airborne
debris.
• DO NOT common vent this water
heater with any other water heaters
or appliances.
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Figure 2 - Minimum Vent Clearance (Indoor
Direct Ven ng)
ϰŌ;ϭϮϮĐŵͿŵŝŶ
ϰŌ;ϭϮϮĐŵͿŵŝŶϰŌ;ϭϮϮĐŵͿŵŝŶ
Figure 3 - Minimum Vent Clearances (Outdoor
Ven ng)
14 • Residen al Gas Tankless Water Heater Use and Care Guide
Included Items
Table 4: Items Included with your Water Heater
Item Product Image Descrip on
Confi gura on
X3 M
Manual
Installa on Instruc ons and Use & Care Guide for
TM-160, TM-180 & TM-199 series model water heaters.
√√
Pressure Relief
Valve
Pressure Relief Valve rated up to 150 psi and the
maximum BTU/hr of the water heater.
(Included with X3® models; Field supplied for M models)
√
Wall Moun ng
Bracket
Kit for moun ng water heater contains:
• Moun ng Bracket (1x)
• 1/4 in x 3 in Lag Bolts (4x)
√√
Screws for
Vent Ports
Screws to secure the vent piping to the vent ports.
See "Installing the Vent Pipe" on page 22.
• 3/16 in x 1/2 in Vent Screw (2x)
√√
Bird Screen
Bird screen to restrict small animals, birds, pests, and
other foreign objects from entering the vent system. Kit
contains 2 screens sized for 2 in vent elbows.
√√
X3® Cartridge
Prevents scale buildup and eliminates the need for annual
descaling maintenance.
√
Bypass
Cartridge
For M confi gura on water heaters without X3® scale
reduc on technology.
√
Cartridge
Screws
(x1)
(x2)
Screws to secure the X3®or Bypass Cartridge:
• M4-12 mm (1x)
• M4-25 mm (2x)
√√
Cascading
Cable
Cascading Cable for electronically connec ng tankless
water heaters in series for greater output:
• P/N 100371915
√√
GETTING STARTED
Residen al Gas Tankless Water Heater Use and Care Guide • 15
GETTING STARTED
Available Accessories
Table 5: Accessories Available for your Water Heater
Item Product Image Descrip on
X3® Cartridge
Add to an M model heater to prevent scale buildup and eliminate the
need for annual descaling maintenance:
• P/N 100368986
Wi-Fi Module
Wi-Fi Module for electronically connec ng tankless water heaters to the
internet and adapter to connect to the water heater:
• P/N 100371922
Remote
Temperature
Controller
Remote Temperature Controller with 10 . (3m) cable:
• P/N 100383909
Communica on
Cables
Communica on Cable Extensions for Remote Temperature Controller, Wi-
Fi Module, or On-Demand Receiver:
• P/N 100377341 for 10 . (3 m)
• P/N 100377342 for 32 . (10 m)
Cartridge Freeze
Protec on
Cartridge Freeze Protec on can add an extra layer of freeze protec on to
external cartridge:
• P/N 100325654 for X3® models
• P/N 100371918 for Bypass models
Pipe Cover
Pipe Cover protects plumbing connec ons to the heater while improving
the appearance of the installa on. Affi xes to bo om of heater:
• P/N 100383908
Neutralizer
Assembly Kit
Neutralizer Assembly neutralizes the condensate (acidic water) that forms
in the secondary heat exchanger of the water heater. It connects to the
condensate drain port of the water heater by using connectors included
with the neutralizer kit:
• P/N 100112159
16 • Residen al Gas Tankless Water Heater Use and Care Guide
Table 5: Accessories Available for your Water Heater
Item Product Image Descrip on
Outdoor Vent
Cap Kit
Outdoor Installa on kit containing the Outdoor Vent Cap and User
Interface Cover:
• P/N 100369060
Isola on Valve
Kit with Pressure
Relief Valve
Isola on Valve supports rou ne maintenance and allows for draining
and fl ushing the heater; whereas, the Pressure Relief Valve, as the name
implies, serves to limit internal pressure in the system:
• P/N 100112156
GETTING STARTED
Recommended Tools
and Materials
Before you start, be sure you have the
following tools and supplies:
• Plumbing tools and supplies appro-
priate for the type of water pipes in
your home.
• Thread sealant tape or pipe joint
compound approved for potable
water.
• Pipe dope approved for gas connec-
ons or gas type.
• For homes with water lines using
threaded connectors suitable for the
specifi c type of plas c pipe used:
CPVC or PEX (cross-linked polyeth-
ylene). Do not use PVC pipe.
• Non-corrosive gas leak detec on
solu on made from hand dishwash-
ing soap mixed with water (1 part
soap to 15 parts water) or children's
soap bubbles and a small, so -bris-
tled brush or approved gas leak
detec on device.
• An appliance dolly or hand truck to
move the water heater.
Recommended
Accessories
• Automa c water leak detec on and
shut-off device
• Thermosta c Mixing Valves at each
point-of-use
• Fuel gas and carbon monoxide
detector
Residen al Gas Tankless Water Heater Use and Care Guide • 17
INSTALLATION
Installa on Environment
Proper Moun ng and
Clearance
The water heater shall be securely
mounted on a wall that can support
the weight of the water heater. A wall
moun ng bracket is supplied with the
water heater to securely mount the
water heater to wall studs. The water
line, gas line, condensate drain line,
and pressure relief valve discharge
line shall be supported using fi eld
supplied pipe hangers. The water
heater shall not bear the weight of
these lines. The water heater requires
proper installa on clearance for
opera on and service as described in
"Unit Clearances" on the right.
WARNING! The installer (licensed
professional) is responsible for the
correct installa on of the water
heater and for compliance with all
na onal, state/provincial, and local
codes.
Atmosphere Temperature
Install the water heater in a
heated area where below freezing
temperatures cannot occur. A pipe
cover is recommended when the
water heater is installed outdoors
because it provides be er protec on
from the elements. The warranty will
not be covered if the water heater is
damaged due to freezing. See "Freeze
Protec on System" on page 53.
Combus on Air Supply
The water heater requires fresh
combus on air and should be
free of corrosive elements and
fl ammable vapors. If it is installed in a
contaminated or confi ned area, direct
ven ng installa on is recommended.
Proper Ven la on
For proper opera on the water heater
must be vented in accordance with
the sec on "Ven ng" of the current
edi on of the ANSI Z223.1/NFPA 54,
Na onal Fuel Gas Code in the United
States and/or Sec on 8 of the B149.1,
Natural Gas and Propane Installa on
Code in Canada, as well as applicable
local building codes.
Condensate Drain Line
The condensate produced is acidic.
Drain the condensate in accordance
with all local codes and common
safety prac ces.
Unit Clearances
WARNING! Maintain all clearances
around the water heater. Failure
to do so could create a fi re hazard,
poten ally leading to death, serious
injury, and/or property damage.
Top: 12 in
(305 mm)
Side: 3 in
(76 mm)
Front: 4 in
(102 mm)
Bottom:
18 in (458 mm)
Back: 0.5 in
(13 mm)
Side: 3 in
(76 mm)
Bottom:
18 in
(458 mm)
Front:
4 in
(102 mm)
Side:
3 in
(76 mm)
Side:
3 in
(76 mm)
Back:
0.5 in
(13 mm)
Top:
12 in
(305 mm)
Overhang:
36 in (914 mm)
Figure 4 - Indoor/Outdoor Clearances
NOTICE: It is recommended that the
front should have 24 inches (610 mm)
of clearance for maintenance.
Moun ng the Water
Heater
1
Secure the wall moun ng
bracket with the four
supplied lag bolts to the wall
studs. See Figure 5. DO NOT secure to
drywall only.
NOTICE: The supplied fasteners are
for wood studs only. When moun ng
on any other surface, use fasteners
approved for that wall material/
construc on. Make sure to level the
bracket.
16” (406.4 mm) Center
New Construction Configuration Shown:
Drywall cut away to show horizontal bracing.
Wall Stud
Wall Stud
Horizontal Blocking - Top
Horizontal Blocking - Bottom
Screws
Figure 5 - Wall Bracket Installa on
2
Hang the heater on the
moun ng bracket (Figure 6).
Figure 6 - Use Moun ng Screws to Secure Water
Heater to Bracket
3
Secure the water heater
fi rmly, fastening the
appropriate screws for wall
construc on into the upper and
bo om brackets of the water heater
and wall. NOTICE: These screws are
not provided.
Securewithscrews.
Figure 7 - Use Moun ng Screws to Secure Water
Heater to Bracket
18 • Residen al Gas Tankless Water Heater Use and Care Guide
Combus on and
Ven ng Installa on
Combus on Air
Before installing the water heater, you
must determine the amount of air
needed to supply this water heater
and any other gas appliances in the
same area and provide adequate air
for combus on and ven la on. This
sec on does not apply if the water
heater is direct vented. Consult a
qualifi ed person if you are unsure of
the proper way to supply air to your
water heater.
WARNING! This gas water heater
requires an adequate source of
clean air for combus on and
ven la on. Without suffi cient air,
your water heater will have frequent
outages and may emit excessive
and abnormal amounts of carbon
monoxide.
Before beginning:
Calculate total BTU/hr ra ng of all
appliances.
To calculate the combus on air and
ven la on required, add up the total
BTU/hr ra ngs of all gas burning
appliances (e.g., water heaters,
furnaces, clothes dryers) in the same
area.
Your water heater’s BTU/hr ra ng is
on the ra ng plate, located on the
side of the water heater. The BTU/
hr ra ngs should be on the other
appliances’ ra ng plates. If you have
trouble determining the BTU/hr
ra ngs, contact the manufacturer or
have a qualifi ed person determine the
ven la on requirements.
NOTICE: If you are replacing your
old water heater with one that has a
higher BTU/hr ra ng, the amount of
ven la on required may be greater.
Example:
Gas Burning Appliance BTU/hr Ra ng
Gas Water Heater 199,000
Furnace 75,000
Dryer 20,000
Total 294,000
Your Appliances:
Gas Burning Appliance BTU/hr Ra ng
Gas Water Heater
Total
Op on A: Installa on without
outside ven la on (not
recommended)
Ven la on with outside air is
recommended for all installa ons.
Even if the water heater is installed in
a large, open room inside the house,
outdoor air is usually needed because
modern homes are very ghtly sealed
and o en do not supply enough air
to the water heater. However, when
installed in a large indoor space, it
may be possible to provide enough air
without outside ven la on. If you are
unsure if your installa on loca on has
enough ven la on, contact your local
gas u lity company or code offi cials
for a safety inspec on.
The following instruc ons will help
determine if it may be possible to
install without outside ven la on. If
there is not enough ven la on, you
will need to ven late with outside air.
Check for Chemicals:
Installa ons where corrosive
chemicals may be present require
outside air. Air for combus on and
ven la on must be clean and free of
corrosive or acid-forming chemicals
such as sulfur, fl uorine, and chlorine.
Ven la on with outside air will reduce
these chemicals, but it may not
completely eliminate them. Failure
due to corrosive chemicals is not
covered by the warranty. Examples of
loca ons that require outside air due
to chemicals include:
• Beauty salons
• Photo processing labs
• Indoor pools
• Laundry, hobby, or cra rooms
• Chemical storage areas
Products such as aerosol sprays,
detergents, bleaches, cleaning
solvents, gasoline, air fresheners,
paint and varnish removers, and
refrigerants should not be stored or
used near the water heater.
A1: Calculate the air volume of
the room
Air requirements depend on the size
of the room.
Floor Area (square feet) x Ceiling
Height (feet) = Room Volume (cubic
feet)
If there are large objects in the
room (e.g., refrigerator, furnace,
car), subtract their volume from the
volume of the room to get a be er
es mate of the air available.
Room Volume – Object Volume = Air
Volume
A2: Calculate required air
volume
A water heater installed in an
unconfi ned space, such as an a c or
garage, requires that the space be at
least 50 cubic feet per 1,000 BTU/hr
of the total input for all gas burning
appliances in the same area.
[Total BTU/hr/1000] x 50 = Cubic feet
of air required.
INSTALLATION
Residen al Gas Tankless Water Heater Use and Care Guide • 19
INSTALLATION
Example:
(294,000 / 1000) x 50 = 14,700
If the air volume of the room is less
than the required air volume, you
must provide two permanent outside
air openings that draw in suffi cient air.
Use Op on B.
If the air volume of the room is
greater than the required air volume,
it may be possible to install the water
heater without outside ven la on.
A3: Check that combus on
ven la on is adequate
Because modern homes are o en
well-sealed to prevent dra s, a
large room may not provide enough
combus on air without ven la on.
Confi rm that your installa on has
enough combus on air.
Op on B: Installa on with
outside ven la on
Ven la on with outside air is
recommended, and for most
installa ons, is needed. There may be
exis ng ven la on that is adequate,
or you may need to add more
ven la on.
Supplying outside air typically requires
two openings. One opening must be
within 12 inches from the fl oor and
the second opening must be within
12 inches from the ceiling. Although
a single opening is not preferred, you
may use a single opening to outside
air if the minimum free area is sized
according to Table 6 (see page 20).
Two openings must be used when
ven la ng with air from another room.
B1: Determine type of
ven la on
There are several types of ven la on
that can be used:
1. Direct to outdoors
2. Ver cal ducts
3. Horizontal ducts
4. Single opening (not recom-
mended); must be at least 100
square inches. Not appropriate
for confi ned spaces smaller than
50 cubic feet per 1,000 Btu/hr as
calculated in sec on A or when
ge ng air from another room.
5. From a larger room inside the
house (not recommended —
refer to sec on A to determine
if the combined volume of the
room may be adequate)
B2: Determine minimum free
area required for each vent
opening
The size of the vent openings depends
on the total BTU/hr ra ng of all
appliances in the space (use your
calcula on from “Before Beginning”)
and the type of vent used. Table 6
provides the minimum free area for
each vent opening depending on the
type of ven la on.
B3: Calculate minimum size of
vent openings and ducts
The vent cross-sec onal area needed
to provide the free area depends on
the covering on the vent openings.
Typical vents use louvers or grilles to
protect the opening. The louver or
grille itself blocks some of the free
area, so the opening may need to be
larger to meet the minimum free area
requirements.
Use the following formula to calculate
the required cross-sec onal area:
Cross-sec onal area = minimum free
area required ÷ percent free area of
covering (in decimals – e.g., 60% = .6)
For example, an installa on area that
requires openings with 100 square
inches of free area would need 134
square inch openings if using metal
louvers rated at 75% free area
(100 sq. in. ÷ .75 = 134 sq. in.).
If you do not know the % free area for
your louver or grille, use the following
values:
• For wood louvers or grilles: 20%
• For metal louvers or grilles: 60%
Follow these rules to ensure that
vents and ducts provide adequate air
fl ow:
• Each vent opening must be no small-
er than 100 square inches.
• Ducts must have the same
cross-sec onal area as free area of
the opening.
• Rectangular ducts must have a
minimum dimension of no less than
three inches.
• All screens must have mesh 1/4 inch
or larger.
• Movable louvers must be locked
open or interconnected with the
equipment so that they open auto-
ma cally during opera on.
• Keep louvers and grilles clean and
free of debris or other obstruc ons.
B4: Check that air source is
clean and free of chemicals
Air for combus on and ven la on
must be clean and free of corrosive
or fl ammable chemicals. A failure due
to corrosive chemicals in the air is not
covered by the warranty. Combus on
air must be free of acid-forming
chemicals such as sulfur, fl uorine, and
chlorine. Be sure that air at the vent
inlets is free of such chemicals.
B5: Check that combus on
ven la on is adequate
Confi rm that your installa on has
enough combus on air.
20 • Residen al Gas Tankless Water Heater Use and Care Guide
Combus on Air Supply Op ons
Gable vent
to outdoors
Install above
insulation
Outlet air to
attic 1 in
2
(6.5 cm
2
)
per 4,000 btu/h
Inlet air from
the crawl space
Open foundation vent
Confined
Space
Alternate
Air Inlet
1 in
2
(6.5 cm
2
)
per 4,000 btu/h
Figure 8 - Direct to Outdoor Openings
Max. 12” (305 mm)
Two permanent
Openings
1 in
2
(6.5 cm
2
)
per 4,000 btu/h
Max. 12” (305 mm)
Confined
Space
Figure 9 - Direct to Outdoor Openings with Two
Permanent Openings
Outlet air to
attic 1 in
2
(6.5 cm
2
)
per 4,000 btu/h
Inlet air duct
1 in
2
(6.5 cm
2
)
per 4,000 btu/h
Confined
Space
Gable vent
to outdoors
Install above
insulation
Max.
12” (305 mm)
Figure 10 - Ver cal Duct Openings
1 in
2
(6.5 cm
2
)
per 2,000 btu/h
Confined
Space
Outlet
Inlet
Outdoor
Air Ducts
1 in
2
(6.5 cm
2
)
per 2,000 btu/h
Figure 11 - Horizontal Duct Openings
Confined
Space
1 in
2
(6.5 cm
2
)
per 3,000 btu/h
Alternative
Opening
Location
Figure 12 - Single Opening
Two permanent
Openings
1 in
2
per
1,000 btu/h
Confined
Space
Max. 12” (305 mm)
Max. 12” (305 mm)
Figure 13 - Two Permanent Openings
Table 6:
Minimum Free Area of Permanent Openings for Ven la on and Combus on Air Supply – Air from outdoor or indoor spaces.
Based on the total BTU/hr input ra ng for all gas burning appliances within a confi ned space.
Opening Source Minimum Free Area
Direct to Outdoors* 1 in² (6.5 cm²) per 4,000 BTU/hr (see Figure 8 & 9)
Ver cal Ducts 1 in² (6.5 cm²) per 4,000 BTU/hr (see Figure 10)
Horizontal Ducts 1 in² (6.5 cm²) per 2,000 BTU/hr (see Figure 11)
Single Opening 1 in² (6.5 cm²) per 3,000 BTU/hr (see Figure 12)
Two Permanent Openings
to Another Room**
1 in² (6.5 cm²) per 1,000 BTU/hr (see Figure 13)
Opening: 100 in² (645 cm²) Min.
Minimum dimension of air openings: no less than 3 inches (76 mm)
*These openings connect directly with the outdoors through a ven lated a c, a ven lated crawl space, or through an outside wall.
**United States: For direc on on combining spaces in diff erent stories within the structure, refer to the current edi on of the
Na onal Fuel Gas Code ANSI Z223.1/NFPA 54. In Canada, follow B149.1, Natural Gas and Propane Installa on Code.
INSTALLATION
Residen al Gas Tankless Water Heater Use and Care Guide • 21
INSTALLATION
Ven ng
WARNING! Carbon Monoxide
Hazard. This water heater must
be supplied with adequate air and
vented to outdoors. The vent system
must be installed by a qualifi ed
person. Examples of a qualifi ed
person include gas technicians,
authorized gas company personnel,
and authorized service technicians.
Failure to properly vent the water
heater can result in severe injury
or death from carbon monoxide
poisoning.
The Indoor model must be vented in
accordance with the current edi on
of ANSI Z223.1/NFPA 54, Na onal
Fuel Gas Code in the USA or B149.1,
Natural Gas and Propane Installa on
Code in Canada, as well as applicable
local building codes.
The use of ven ng materials approved
for Category III/IV appliances is
recommended whenever possible.
However, the Indoor model may also
be vented with plas c pipe materials
such as ABS, PVC (solid core), CPVC
(solid core), or polypropylene.
For details, please refer to the
Exhaust Vent Sec on on page 24. Vent
installa ons in Canada which u lize
plas c vent systems must use ven ng
that complies with ULC S636.
Ven ng may not intermingle with
other manufactured material types,
other than approved adapters.
General Rules for Ven ng
Water Heaters:
• Follow the vent pipe's manufactur-
er's instruc ons when installing the
vent pipe.
• Place the water heater as close as
possible to the vent termina on.
• The vent collar of the water heat-
er must be fastened directly to an
unobstructed vent pipe.
• Do not weld, glue or permanently
bond the vent pipe to the water
heater's vent collar.
• Do not cut or alter the vent collar of
the unit.
• The vent must be easily removable
from the top of the water heater for
normal service and inspec on of the
unit and vent system.
• The water heater vent must not be
common vented to any other gas
appliance or vent stack.
• Air supply pipe can be made of ABS,
PVC (solid core), CPVC (solid core),
polypropylene, or Category lll/IV
stainless steel.
• Use of cellular core PVC (ASTM
F891), cellular core CPVC, or Radel®
(polyphenylsulfone) in nonmetallic
ven ng systems is prohibited.
• Covering non-metallic vent pipe and
fi ngs with thermal insula on is
prohibited.
• Sidewall ven ng is recommended
for the Indoor model. Ver cal vent-
ing (roof termina on) is acceptable.
• The manufacturer recommends run-
ning the exhaust vent and the intake
pipe as parallel as possible.
• For roo op ven ng, a rain cap or
other form of termina on that pre-
vents rainwater from entering into
the water heater must be installed.
• Do not terminate vent into a chim-
ney. If the vent must go through
the chimney, the vent must run all
the way through the chimney with
approved vent pipe.
• The water heater shall not be
connected to a chimney fl ue serving
a separate appliance, designed to
burn solid fuel.
General Rules for Vent
Termina ons:
• Avoid loca ng the water heater
vent termina on near any air intake
devices. These fans can pick up
the exhaust fl ue products from the
water heater and return them to the
building. This can create a health
hazard.
• Locate the vent termina on so that
it cannot be blocked by any debris,
at any me. Most codes require that
the termina on be at least 12 inches
(305 mm) above grade and an ci-
pated snow level, but the installer
may determine if it should be higher
depending on the job site condi on
and applicable codes.
• A proper sidewall termina on is rec-
ommended when the water heater
is vented through a sidewall.
• Check the clearances from the
exhaust termina on to the air inlet
or opening.
• To reduce the risk of carbon mon-
oxide poisoning, install a fuel gas
and carbon monoxide detector.
Install and maintain the detector in
accordance with the manufacturer's
instruc ons and local codes.
Replacing a Water Heater
Using the Exis ng Vent System
WARNING! Improper ven ng of
this appliance can result in excessive
levels of carbon monoxide which
can result in severe personal injury
or death. Improper installa on
can cause nausea or asphyxia on,
severe injury or death from carbon
monoxide and fl ue gases poisoning.
The product warranty will not apply
to improper installa ons.
DO NOT use Category I or Category II
ven ng system with this water heater.
If exis ng ven ng and vent
termina ons are used, they MUST be
cleared of ALL restric ons, such as a
restrictor plate, for proper opera on.
Read the “Installing Vent Pipe” sec on
of this manual and make sure your
vent system is properly installed.
Inspect the exis ng vent system for
obstruc ons, corrosion, and proper
installa on. Repair or replace if
necessary.
22 • Residen al Gas Tankless Water Heater Use and Care Guide
Table 7: Acceptable Plas c Vent Pipe Table
Item Material United States Canada
Exhaust Pipe and
Fi ngs
Schedule 40 PVC ANSI/ASTM D1785
ULC S636 Cer fi ed
Materials Only
PVC-DWV ANSI/ASTM D2665
Schedule 40 CPVC ANSI/ASTM F441
Schedule 40 ABS-DWV ANSI/ASTM D2661
Polypropylene UL-1738
Pipe Cement/
Primer
PVC ANSI/ASTM D2564
ULC S636 Cer fi ed
Materials Only
CPVC ANSI/ASTM F493
ABS ANSI/ASTM D2235
Use of cellular core PVC (ASTM F891), cellular core CPVC, or Radel® (polyphenylsulfone) in non-metallic ven ng systems is
prohibited. Covering non-metallic vent pipe and fi ngs with thermal insula on is prohibited.
NOTE: Approved vent and air intake polypropylene vent materials: Centrotherm InnoFlue® Single Wall Vent System.
Table 8: Maximum Vent Length with Elbows
Number of Elbows
Maximum Ver cal or Horizontal Vent Length
0 to 7,800 . (0 to 2,377 m)
2 Inch Ven ng (50 . / 15.3 m) 3 Inch Ven ng (150 . / 45.7 m)
0 50 . (15.3 m) 150 . (45.7 m)
1 47 . (14.3 m) 147 . (44.8 m)
2 44 . (13.4 m) 144 . (43.9 m)
3 41 . (12.5 m) 141 . (43.0 m)
4 38 . (11.6 m) 138 . (42.1 m)
5 35 . (10.7 m) 135 . (41.1 m)
• For details on the vent connec on, refer to "Installing the Vent Pipe" on page 23.
• For each elbow added, deduct 3 . (0.9 m) length for the elbow from maximum vent length.
• Total vent length will be used to confi gure the water heater a er installa on. See "Confi gura on Mode (C Mode)" on pages
50-51.
INSTALLATION
Pipe end
not flush
with base.
Exhaust
Vent
Pipe
Not a
90° edge
Pipe end
is flush
with base.
Exhaust
Vent
Pipe
90° edge
Figure 14 - Insert Straight Pipe
Clamp
Self-Tapping Screw
Figure 15 - Secure Ven ng
3" Pipe
2" to 3"
Adapter
2" Pipe
2" Pipe
Figure 16 - Direct Vent Installa on
3" Pipe
2" to 3"
Adapter
2" Pipe
3" Elbow
2" Elbow
Air
Intake
Air
Intake
2" to 3"
Adapter
2" Pipe
2" Pipe
Figure 17 - Power Vent Installa on
Residen al Gas Tankless Water Heater Use and Care Guide • 23
INSTALLATION
Installing the Vent Pipe
WARNING! Improper installa on
can cause nausea or asphyxia on,
severe injury or death from carbon
monoxide and fl ue gases poisoning.
The product warranty will not apply
to improper installa ons.
• When inser ng the pipe into the
exhaust/intake port, make sure that
the pipe end is cut straight and posi-
oned properly under the O-ring to
seal the connec on fi rmly.
• Improper ven ng of this appliance
can result in excessive levels of car-
bon monoxide which can result in
severe personal injury or death.
Vent Piping
1
Insert 2 inch straight pipe
into the exhaust/intake ports
un l fully seated (Figure 14).
The pipes will insert at a minimum of
1.5 inches (38 mm).
NOTICE: Air Intake for 2 inch Power
Vent Installs: Insert the male end of a
2 inch long sweep street elbow into
the heater’s air intake port.
WARNING! The exhaust vent pipe
connec on to the water heater must
be fl ush to maintain a proper seal.
Check pipe for a 90° edge before
installa on. DO NOT use a fi eld cut
end for the connec on. Failure to
follow these instruc ons can cause
carbon monoxide poisoning or death.
For 3 inch piping, install a 2 inch
x 3 inch increaser to convert to 3
inch ven ng. A 12 inch (305 mm)
maximum length straight pipe may be
used to fi t a 2 inch x 3 inch increaser
(Figures 16 & 17).
2
Use a Phillips screwdriver to
ghten the clamps (Figure
15).
3
Use the specifi ed self-tapping
screws to secure the ven ng
to the intake and exhaust
ports (Figure 15).
Exhaust Vent for Indoor
Installa on
ABS, PVC, CPVC or
Polypropylene vent
The Indoor model can be vented with
ABS, PVC (temperature rated up to
149°F/65°C), CPVC or polypropylene.
In Canada, plas c ven ng must be
cer fi ed to ULC S636 standards.
• The maximum length of the exhaust
ven ng and intake piping shall not
exceed the lengths listed in Table 8.
• DO NOT use more than 5 elbows in a
vent system. 2 inch and 3 inch
90° elbows are equivalent to a vent
length of 3 . (0.9 m). 2 inch and 3
inch 45° elbows are equivalent to
a vent length of 1 . (0.3 m). If an
elbow is used in the vent system,
deduct each equivalent length from
the maximum vent length to decide
the total vent lengths.
• When the horizontal vent run ex-
ceeds 5 . (1.5 m), support the vent
run at 3 . (0.9 m) intervals with
overhead hangers.
• In areas of high rainfall, the installa-
on of the rain trap may be neces-
sary.
• Slope horizontal ven ng sec ons
1/4 inch (6 mm) upwards for every
12 inches (305 mm) toward the
termina on or according to local
or state/provincial codes, or in the
absence of local or state/provincial
codes, the current edi on of ANSI
Z223.1/NFPA 54, Na onal Fuel Gas
Code in the USA or B149.1, Natural
Gas and Propane Installa on Code
in Canada, as well as applicable local
building codes.
• Do not use ght 90° elbows. Stan-
dard and long sweep elbows are
acceptable. See Figure 18.
Not Recommended
90° Vent
Elbow
Recommended
90° Sweep
Elbow
90° Long
Sweep
Elbow
Figure 18 - Acceptable/Unacceptable Elbows
Input Rate at Maximum
Vent Length
The manufacturer recommends using
the shortest vent length possible to
install the water heater. Pressure drop
across ven la on at maximum vent
length will decrease the input rate of
the water heater.
NOTICE: Table 9 describes the input
derate at maximum vent length per
vent sizing.
Table 9: Input Decrease at Maxi-
mum Vent Length
Model
Vent
Size
Derate at Max.
Vent Length
TM-160
2 Inch 25%
3 Inch 20%
TM-180
2 Inch 30%
3 Inch 25%
TM-199
2 Inch 45%
3 Inch 25%
24 • Residen al Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Typical PDV Confi gura ons:
The following are typical ven ng confi gura on examples for
Power Direct Vent (PDV) applica ons.
Hanger
H
an
g
er
Figure 19 - Power Direct Vent Horizontal Installa on
Fire Stop
Roof
Figure 20 - Power Direct Vent Ver cal Installa on
Typical PV Confi gura ons:
The following are typical ven ng confi gura on examples for
Power Vent (PV) applica ons.
Hanger
Hanger
Figure 21 - Power Vent Horizontal Installa on
Roof
Flashing
Fire
Stop
Figure 22 - Power Vent Ver cal Installa on
Residen al Gas Tankless Water Heater Use and Care Guide • 25
INSTALLATION
26 • Residen al Gas Tankless Water Heater Use and Care Guide
Vent Termina ons
Table 10: PVC Vent Termina ons and Ven ng Components
PVC LOW PROFILE TERMINATION
If termina on is
used in ver cal
posi on, the
exhaust port must
be oriented at the
top.
Vent Pipe Size PVC Kit Number IPEX Part Number
IPEX System 1738 ®
PVC Part Number
*Equivalent Length
2" Low Profi le 100187903 196984 397984 1 .
3" Low Profi le 100187887 196985 397985 1 .
PVC CONCENTRIC TERMINATION
B
A
C
ABC
FGV 2" 29” 16" 2"
FGV 3" 36” 20" 3"
Vent
Pipe Size
PVC Kit
Number
IPEX
PVC Part Number
IPEX System 1738 ®
PVC Part Number
IPEX System 636®
CPVC Part Number
*Equivalent Length
2" FGV 100112869 196005 397005 197040 7 .
3" FGV 100112163 196006 397006 197006 23 .
3" Low Profi le Termina on ISLPT0303 5 .
Table 11: Polypropylene Vent Termina ons and Ven ng Components
POLYPROPYLENE CONCENTRIC TERMINATION
Vent Pipe Size Centrotherm Part Number *Equivalent Length
2" Low Profi le Termina on ISLPT0202 6 .
3" Low Profi le Termina on ISLPT0303 5 .
INSTALLATION
Residen al Gas Tankless Water Heater Use and Care Guide • 27
Table 11: Polypropylene Vent Termina ons and Ven ng Components
POLYPROPYLENE RADIUS ELBOWS
Vent Pipe Size Centrotherm Part Number *Equivalent Length
2" 45° Exhaust Elbow ISELS0245UV 2 .
3" 45° Exhaust Elbow ISELS0345UV 2 .
2" 87° Inlet Elbow ISELS0287UV 3 .
3" 87° Inlet Elbow ISELS0387UV 3 .
POLYPROPYLENE CONCENTRIC WALL TERMINATION
(ICWT242)
(ICTCR24)
Vent Pipe Size Centrotherm Part Number(s) *Equivalent Length
2" ICWT242, ICTCR24 12 .
(ICWT352) (ICCT3503)
Vent Pipe Size Centrotherm Part Number(s) *Equivalent Length
3" ICWT352, ICCT3503 9 .
*IMPORTANT!: Do not exceed 50 . (15.3 m) for 2 inch ven ng or 150 . (45.7 m) for 3 inch ven ng. Each elbow added is the
equivalent length of 3 . for both 2 inch and 3 inch ven ng. Make note of total vent length for your applica on, including vent
termina on. See "Confi gura on Mode (C Mode)" on pages 50-51.
INSTALLATION
28 • Residen al Gas Tankless Water Heater Use and Care Guide
Vent Termina on Clearances
H
D
E
L
B
V
V
V
V
B
F
C
B
B
B
V
V
V
V
V
X
X
A
J
M
Operable
Fixed
closed
Fixed
closed
Operable
B
Inside corner
detail
G
A
K
V
X
= Vent terminal
= Air supply inlet
= Area where the terminal
ŝƐŶŽƚƉĞƌŵŝƩĞĚ
Regulator/Gas meter
vent outlet
I
Table 12: Vent Termina on Clearances
Canada Installa ons
1
US Installa ons
2
Direct Vent and
Other than Direct Vent
Direct Vent Other than Direct Vent
A Clearance above grade, veranda, porch, deck, or balcony 1 (30 cm) 1 (30 cm)
B Clearance to window or door that may be opened 3 (30 cm) 1 (30 cm)
4 (1.2 m) below or to
side of opening; 1
(30 cm) above opening
C Clearance to permanently closed window 0 0 0
D
Ver cal clearance to ven lated soffi t located above the
terminal within a horizontal distance of 2 (61 cm) from
the center line of the terminal
3 (91 cm) 3 (91 cm) 3 (91 cm)
E Clearance to unven lated soffi t 3 (91 cm) 3 (91 cm) 3 (91 cm)
F Clearance to outside corner 2 (61 cm) 2 (61 cm) 2 (61 cm)
G Clearance to inside corner 2 (61 cm) 2 (61 cm) 2 (61 cm)
H
Clearance to each side of center line extended above
meter/regulator assembly
3 (91 cm) * *
I Clearance to service regulator vent outlet
Above a regulator within 3 (91
cm) horizontally of the ver cal
center line of the regulator vent
outlet to a maximum ver cal
distance of 15 (4.5 m)
**
J
Clearance to non-mechanical air supply inlet to a
building or the combus on air inlet to any other
appliance
3 (91 cm) 1 (30 cm)
4 (1.2 m) below or to
side of opening; 1
(30 cm) above opening
K Clearance to mechanical air supply inlet 6 (183 cm)
3 (91 cm) above if within 10 (3 m)
horizontally
L
Clearance above paved sidewalk or paved driveway
located on public property
7 (213 cm)** 7 (213 cm) 7 (213 cm)
M Clearance under veranda, porch deck, or balcony 1 (30 cm)*** 1 (30 cm)*** 1 (30 cm)***
*Clearance in accordance with local installa on codes and the requirements of the gas supplier.
**A vent shall not terminate directly above a sidewalk of paved driveway that is located between two single family dwellings and serves both dwellings.
***Permi ed only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the fl oor.
The vent for condensing water heaters shall not terminate:
• over public walkways; or
• near soffi t vents or crawl space vents or other areas where condensate or vapor could create a nuisance or hazard or cause property damage; or
• where condensate vapor could cause damage or could be detrimental to the opera on of regulators, relief valves, or other equipment.
Notes:
1) In accordance with the current CSA B149.1, Natural Gas and Propane Installa on Code.
2) In accordance with the current ANSI Z223.1/NFPA 54, Na onal Fuel Gas Code.
INSTALLATION
Residen al Gas Tankless Water Heater Use and Care Guide • 29
INSTALLATION
Clearances for Sidewall
Termina ons
WARNING! Improper installa on
can result in carbon monoxide
poisoning or death. Follow all local
and na onal codes regarding proper
termina on clearances. In the
absence of such codes, the clearances
below can be used as guidelines.
Local codes supersede these
guidelines.
Mul ple Sidewall Termina ons
An exhaust termina on must be at
least 1 . (305 mm) from another
exhaust termina on and 2 . (610
mm) form an inside corner (Figure
23).
Exhaust termina ons should be at
least 2 . (610 mm) away from an
opposite surface/wall. Do not place
the termina on directly in front of an
opening into a building (Figure 24).
Mul ple Direct Vent Sidewall
Termina ons
A direct vent (DV) termina on must
be at least 1 . (305 mm) from
another DV termina on and 2 .
(610 mm) from an inside corner
(Figure 25).
DV sidewall termina ons should be
at least 2 . (610 mm) away from an
opposite surface/wall. Do not place
the termina on directly in front of an
opening into a building (Figure 24).
Anticipated Snow Level
1 ft
(305 mm)
min.
Inside
Corner
Exhaust Terminations
1 ft
(305 mm)
min.
1 ft
(305 mm)
min.
2 ft
(610 mm)
min.
Figure 23 - Mul ple Sidewall Termina ons
Exhaust
Termination
2 ft
(610 mm)
min.
Figure 24 - Sidewall Termina on Minimum Distance to Opposite Surface/Wall
Anticipated Snow Level
Inside
Corner
DV Exhaust Terminations
1 ft
(305 mm)
min.
1 ft
(305 mm)
min.
1 ft
(305 mm)
min.
2 ft
(610 mm)
min.
Figure 25 - Mul ple DV Sidewall Termina ons
30 • Residen al Gas Tankless Water Heater Use and Care Guide
Power Direct Vent (PDV) Sidewall Termina ons with Separate Penetra ons
For PDV termina ons that use two separate penetra ons for the intake and exhaust, keep the termina on clearances as shown
in the diagrams below.
INSTALLATION
0.5 ft.
(159 mm)
min.
0.5 ft.
(159 mm)
min.
1 ft.
(305 mm)
min.
Exterior InteriorSideview
Figure 26 - Separate Sidewall Penetra on Example A
0.5 ft.
(159 mm)
min.
0.5 ft.
(159 mm)
min.
1 ft.
(305 mm)
min.
Exterior InteriorSideview
Figure 27 - Separate Sidewall Penetra on Example B
Residen al Gas Tankless Water Heater Use and Care Guide • 31
Clearances for Roo op
Termina ons
WARNING! Follow all local and
na onal codes regarding proper
termina on clearances. In the
absence of such codes, the clearances
below must be met. Local codes
supersede these clearances. Failure
to observe this warning may result in
severe personal injury or death.
NOTICE: Canadian requirements diff er
from the guidelines in this sec on. In
Canada, follow the requirements of
the current edi on of B149.1, Natural
Gas and Propane Installa on Code
as well as local and provincial codes.
Contact your local code enforcement
agency for direc on.
• Exhaust termina ons must be at
least 1 . (305 mm) away from any
obstruc ons.
• Minimum spacing between mul ple
intake terminals is 1 . (305 mm).
• Minimum spacing between mul ple
exhaust terminals is 1 . (305 mm).
• The exhaust termina on must be
a horizontal distance of at least 2
. (610 mm) from a wall or surface
unless specifi ed diff erently by local
code.
• Failure to observe this warning may
result in severe personal injury or
death.
INSTALLATION
1 ft (305 mm) min.
1 ft (305 mm)
min. above anticipated
snow level.
* Anticipated Snow
Level.
1 ft (305 mm) min.
1 ft (305 mm)
min. above anticipated snow level.
3 ft (914 mm) min.
Anticipated Snow Level
ISO VIEW
SIDE VIEW
Exhaust Vent
Air Intake
Typical Power Direct Vent (PDV) Installation
&ŽůůŽǁĂůůůŽĐĂůĂŶĚŶĂƟŽŶĂůĐŽĚĞƐƌĞŐĂƌĚŝŶŐƉƌŽƉĞƌƚĞƌŵŝŶĂƟŽŶĐůĞĂƌĂŶĐĞƐ/ŶƚŚĞĂďƐĞŶĐĞŽĨƐƵĐŚĐŽĚĞƐƚŚĞĐůĞĂƌĂŶĐĞƐďĞůŽǁ
ŵƵƐƚďĞŵĞƚ>ŽĐĂůĐŽĚĞƐƐƵƉĞƌƐĞĚĞƚŚĞƐĞĐůĞĂƌĂŶĐĞƐ
Figure 28 - Pitched Roof with Mul ple Vent Termina ons
32 • Residen al Gas Tankless Water Heater Use and Care Guide
INSTALLATION
1 ft (305 mm) min.
1 ft (305 mm) min.
* Anticipated Snow
Level (ASL).
Exhaust Vent
3 ft (914 mm) min.
Anticipated Snow Level
ISO VIEW
FRONT
FRONT
FRONT
SIDE VIEW
1 ft (305 mm) min.
above anticipated snow level.
1 ft (305 mm) min.
above anticipated snow level.
Exhaust Vent
Air Intake
Air Intake
Typical PDV Concentric Installation
&ŽůůŽǁĂůůůŽĐĂůĂŶĚŶĂƟŽŶĂůĐŽĚĞƐƌĞŐĂƌĚŝŶŐƉƌŽƉĞƌƚĞƌŵŝŶĂƟŽŶĐůĞĂƌĂŶĐĞƐ/ŶƚŚĞĂďƐĞŶĐĞŽĨƐƵĐŚĐŽĚĞƐƚŚĞĐůĞĂƌĂŶĐĞƐďĞůŽǁ
ŵƵƐƚďĞŵĞƚ>ŽĐĂůĐŽĚĞƐƐƵƉĞƌƐĞĚĞƚŚĞƐĞĐůĞĂƌĂŶĐĞƐ
Figure 29 - Pitched Roof with Mul ple Ver cal Concentric Termina ons
Residen al Gas Tankless Water Heater Use and Care Guide • 33
INSTALLATION
Anticipated Snow Level
Anticipated Snow Level
1 ft (305 mm)
min. above anticipated
snow level.
Exhaust Vent
3 ft (914 mm) min.
1 ft (305 mm)
min. above anticipated
snow level.
3 ft (914 mm) min.
ISO VIEW
TOP VIEW
SIDE VIEW
1 ft (305 mm) min.
2 ft (610 mm) min.
from wall or surface.
SIDE VIEW
TOP VIEW
ISO VIEW
Exhaust Vent
3 ft (914 mm) min.
1 ft (305 mm)
min. above anticipated
snow level.
1 ft (305 mm)
min. above anticipated
snow level.
3 ft (914 mm) min.
1 ft (305 mm) min.
2 ft (610 mm) min.
from wall or surface.
&ŽůůŽǁĂůůůŽĐĂůĂŶĚŶĂƟŽŶĂůĐŽĚĞƐƌĞŐĂƌĚŝŶŐƉƌŽƉĞƌƚĞƌŵŝŶĂƟŽŶĐůĞĂƌĂŶĐĞƐ/ŶƚŚĞĂďƐĞŶĐĞŽĨƐƵĐŚĐŽĚĞƐƚŚĞĐůĞĂƌĂŶĐĞƐďĞůŽǁ
ŵƵƐƚďĞŵĞƚ>ŽĐĂůĐŽĚĞƐƐƵƉĞƌƐĞĚĞƚŚĞƐĞĐůĞĂƌĂŶĐĞƐ
Wall
Typical Flat Roof Terminations
(Both Single and Multiple)
Exhaust Vent
Air Intake
Air Intake
Exhaust Vent
Air Intake
FRONT
FRONT
FRONT
FRONT
FRONT
FRONT
Wall Wall
Wall Wall
Wall
Figure 30 - Flat Roof with Mul ple Ver cal Termina ons
Exhaust Vent for
Outdoor Installa on
1
Turn OFF power and gas
supply to the water heater.
Remove the four screws from
the top plate of the water heater as
shown in Figure 31.
Screws (4x)
Figure 31 - Remove Screws from Top Plate
2
Orient the outdoor vent cap
as shown in Figure 32. Secure
the outdoor vent cap with
the four screws removed in the
previous step.
Figure 32 - Orient and Install Vent Cap
3
Once the outdoor vent cap is
secured to the water heater,
install the UIM overlay to the
digital display to protect it from
hazardous weather condi ons and
accidental control adjustments (Figure
33).
Figure 33 - Install UIM Overlay
4
Remove the front cover to
the water heater cabinet.
5
Locate the air inlet plate as
shown in Figure 34. Remove
and keep the 3 screws
securing it to the base of the water
heater. The plate is color coded, and it
should be rotated so that the yellow
side of the plate is rotated upward.
Secure with the 3 screws removed
earlier.
INDOOR CONFIGURATION
OUTDOOR CONFIGURATION
Figure 34 - Air Inlet Plate Orienta on
6
Install front cover to water
heater.
7
Connect power to the water
heater. See “Electrical
Connec ons” on page 42.
NOTICE: This water heater comes
equipped with a SJWT rated cord
which is weather resistant and rated
for outdoor use. See “Electrical
Connec ons” on page 42.
Outdoor Available
Accessories
It is recommended that a Cartridge
Freeze Protec on Kit be installed if
the water heater is installed outside
or in uncondi oned areas subject to
freezing temperatures.
A pipe cover is available and affi xes
to the bo om of the water heater.
It protects plumbing connec ons to
the water heater while improving the
appearance of the installa on.
For more informa on see “Available
Accessories” on page 15.
34 • Residen al Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Residen al Gas Tankless Water Heater Use and Care Guide • 35
INSTALLATION
Gas Supply and Gas
Pipe Sizing
Gas Piping
WARNING! This water heater is
designed for Natural Gas opera on
only. Refer to the water heater’s
ra ng plate. Failure to follow these
instruc ons can result in serious
injury or death from explosion, fi re or
carbon monoxide poisoning.
Ensure that any and all gas regulators
used are opera ng properly and
providing gas pressures within the
specifi ed range as shown in Table 13.
Excess gas inlet pressure may cause
serious accidents.
Gas piping must be installed according
to local and state/provincial codes,
or in the absence of these codes, the
current edi ons of ANSI Z223.1/NFPA
54, Na onal Fuel Gas Code in the USA
or B149.1, Natural Gas and Propane
Installa on Code in Canada.
• DO NOT a ach the gas line to the
water heater un l a er the supply
line pressure tes ng has been com-
pleted to avoid any damage to the
water heater.
• The minimum and maximum inlet
gas pressures are shown in Table 13:
Table 13: Minimum & Maximum Inlet
Gas Pressures
Gas Type Inlet Gas Pressure
Natural
Gas
Min. 4.0" W.C. (1.0 kPa)
Max. 10.5" W.C. (2.62 kPa)
Size the gas pipe appropriately to
supply the necessary volume of
gas and allowable pressure drop
required for the water heater using
the manufacturer's gas piping
instruc ons, local and state/provincial
codes, or in the absence of these
codes, the current edi ons of ANSI
Z223.1/NFPA 54, Na onal Fuel Gas
Code in the USA or B149.1, Natural
Gas and Propane Installa on Code in
Canada. Otherwise, fl ow capabili es
and output temperatures will be
limited. See Table 14.
NOTICE: If you are replacing a smaller
input water heater, you may need to
increase the gas line size.
• Inlet gas pressures that fall outside
the range of values listed above may
adversely aff ect the performance
of the water heater. These pres-
sures are measured when the water
heater and any other gas appliance
served by the same gas line are in
full opera on.
• Inlet gas pressure must not exceed
the maximum values in Table 13; gas
pressure above the specifi ed range
will cause dangerous opera ng con-
di ons and damage the unit.
• If the gas supply pressure to the
heater is greater than the specifi ed
maximum, a fi eld-supplied regula-
tor is required. The regulator must
lower the gas pressure within the
approved range.
• Install the gas regulator according
to the manufacturer’s instruc ons.
Some manufacturers may require a
certain amount of straight pipe on
the outlet prior to any addi onal
fi ngs.
• The regulator must be sized for the
water heater's minimum to maxi-
mum input and provide the speci-
fi ed pressures that are listed on the
ra ng plate.
• In the absence of minimum install
distance stated by the regulator
manufacturer, it is recommended
that there be at least 3 . (0.9 m) of
piping between the regulator outlet
and the water heater's inlet gas
connec on.
Gas Connec ons
1
Use a 3/4 inch union to
connect gas piping to the
water heater's 3/4 inch male
NPT connec on.
NOTICE: Refer to Table 14 if 1/2 inch
piping is desired. If the maximum
input of the unit is greater than the
maximum delivery capacity for the
installa on's length of 1/2 inch pipe,
then 3/4 inch piping is required.
2
Install a full port manual gas
shut-off valve between the
water heater and the gas
supply line.
3
When the gas connec ons
are completed, it is necessary
to perform a gas leak test
either by applying soapy water to all
gas fi ngs and observing for bubbles
or by using a gas leak detec on
device.
• The water heater and its individual
shut-off valve must be disconnected
from the gas supply piping system
during any pressure tes ng of that
system at test pressures in excess of
1/2 psi (3.5 kPa).
• The water heater must be isolated
from the gas supply piping system
by closing its individual manual shut-
off valve during any pressure tes ng
of the gas supply piping system at
test pressures equal to or less than
1/2 psi (3.5 kPa).
4
Always purge the gas line of
any debris and/or water
before connec ng to the gas
inlet.
36 • Residen al Gas Tankless Water Heater Use and Care Guide
Natural Gas Supply Piping
Maximum delivery capacity of cubic
feet of gas per hour of IPS pipe
carrying Natural Gas with 0.60 specifi c
gravity based on 0.5" W.C. pressure
drop.
Based on Energy Content of 1,000
BTU/Cubic feet, the water heater
requires:
• 160 ³/hr for the TM-160 model
• 180 ³/hr for the TM-180 model
• 199 ³/hr for the TM-199 model
Table 14 below is from ANSI Z223.1/
NFPA 54.
Gas Sizing Example
Based on Energy Content of 1,000
BTU/Cubic feet (Figure 35):
1
Divide each appliance's
BTU/h requirement by 1,000
BTU/ ³ to get the appliance's
³/h requirement. Take into account
the distance the appliance is from the
gas meter. Use Table 14 and Figure 35
below to properly size the line.
2
For sec ons of the gas line
supplying gas to more than
one appliance (e.g., Point A
to Point B), add up the cubic feet per
hour requirements of the appliances
that are being supplied by that
sec on, and size to the farthest
appliance.
FOR EXAMPLE: The sec on from
A to B supplies gas to the furnace,
range and dryer. Adding up the BTU/h
requirement and dividing by 1,000
yields a cubic per hour requirement
of 220 cubic of gas per hour. The
farthest appliance is the range, which
is 50 away from the meter. Looking
at the chart below, and under the
column of 50 , Sec on A to B needs
to be 1" in order to supply 220 cubic
feet.
INSTALLATION
Table 14: Natural Gas Supply Piping Unit: Cubic feet per hour
Pipe Size Length: (m)
Diameter:
in.
10'
(3.0)
20'
(6.1)
30'
(9.1)
40'
(12.2)
50'
(15.2)
60'
(18.3)
70'
(21.3)
80'
(24.4)
90'
(27.4)
100'
(30.5)
125'
(38.1)
150'
(45.7)
200'
(61.0)
1/2" 172 118 95 81 72 65 60 56 52 50 44 40 34
3/4" 360 247 199 170 151 137 126 117 110 104 92 83 71
1" 678 466 374 320 284 257 237 220 207 195 173 157 134
1-1/4" 1,309 957 768 657 583 528 486 452 424 400 355 322 275
1-1/2" 2,090 1,430 1,150 985 873 791 728 677 635 600 532 482 412
2" 4,020 2,760 2,220 1,900 1,680 1,520 1,400 1,300 1,220 1,160 1,020 928 794
Water
Heater
199,000 BTU/h
AB
C
Dryer
35,000 BTU/h
Gas Meter
Furnace
120,000 BTU/h
Range
65,000 BTU/h
5' (1.5 m) Length
1-1/4" Pipe Size
5' (1.5 m) Length
1-1/4" Pipe Size
10' (3 m) Length
1/2" Pipe Size
10' (3 m) Length
1" Pipe Size
10' (3 m) Length
3/4" Pipe Size
15' (4.6 m) Length
1" Pipe Size
10' (3 m) Length
1/2" Pipe Size
15' (4.6 m) Length
1/2" Pipe Size
Figure 35 - Pipe Sizing Diagram
Water Connec ons
WARNING! DO NOT use this
appliance if any part has been
under water. Immediately contact a
qualifi ed installer or service agency
to replace a fl ooded water heater.
DO NOT a empt to repair the unit! It
must be replaced!
IMPORTANT: DO NOT reverse the hot
outlet and the cold inlet connec ons
to the water heater. If you reverse the
connec ons, the water heater will not
ac vate properly.
Determine the type of water pipes in
your home. Use fi ngs appropriate
for the type of pipe in your home
(copper, CPVC or PEX). Do not use iron
or PVC pipe – they are not suitable
for potable water. All pipes, pipe
fi ngs, valves and other components,
including soldering materials, must
be suitable for potable water system.
Also, an automa c air vent or air
separator must be installed when
the water heater operates in a closed
loop system such as a recircula on
system. Trapped air bubbles in the
water system can cause a pump to
cavitate or damage the water heater's
heat exchanger. This equipment
must be installed according to its
manufacturer's instruc ons.
A manual shut-off valve must be
installed on the cold water inlet to the
water heater between the main water
supply line and the water heater. In
addi on, a manual shut-off valve is
also recommended on the hot water
outlet.
A thermal expansion tank or code
approved device to handle thermal
expansion must be installed and
charged to match the supply pressure
as per the thermal expansion tank
manufacturer's instruc on.
Making Water Connec ons
IMPORTANT: Before installing the
water heater, fl ush the water line
to remove all debris, and a er
installa on is complete, purge the air
from the line. Failure to do so may
cause damage to the heater.
NOTICE: There is a wire mesh fi lter
within the cold inlet to trap debris
from entering your water heater. This
will need to be cleaned periodically to
maintain op mum fl ow.
The water inlet and outlet threaded
connec ons are brass. When
connec ng the unit to piping made of
a diff erent material, use of a dielectric
fi ng or a dielectric union conforming
to ASSE 1079 is recommended to
prevent corrosion and poten al
subsequent water leaks at or near the
connec on. Dielectric fi ngs may be
required by local plumbing codes.
1
Connect the hot water supply
using 3/4 inch NPT to the
fi ng marked "HOT." Follow
the same connec on guidelines as for
the cold water supply marked "COLD."
2
Double check to make sure
the hot and cold water pipes
are connected to the correct
hot and cold water fi ng on the
water heater.
3
Install insula on (or heat
tape) on the water pipes
especially if the indoor
installa on area is subject to freezing
temperatures. Insula ng the hot
water and return pipes will reduce
heat loss.
4
If water hammer is evident,
install water hammer
arrestors on the inlet side of
the water heater.
5
If needed, install (or adjust)
the home's Pressure
Reducing Valve.
6
A drain pan, or other means
of protec on against water
damage, is recommended to
be installed under the water heater in
case of leaks.
IF YOU HAVE COPPER PIPES
If your home has copper water
pipes, you can solder the water pipe
connec ons or use compression
fi ngs which do not require
soldering. Compression fi ngs
are easier to install than soldering
pipe. Check with local plumbing
offi cials to determine what types of
pipe materials are suitable for your
loca on. DO NOT use lead-based
solder.
NOTICE: DO NOT solder pipes while
they are a ached to the water
heater. The water heater contains
non-metallic parts which could be
damaged. The proper way to connect
the water heater to copper water
pipes is as follows:
1
Solder a short length of pipe
(about a foot or so) to a
threaded adapter using only
95/5 n an mony or equivalent
solder.
2
A ach the threaded adapters
to the water heater's
connec ons (using thread
sealant tape or pipe joint compound).
3
Connect the home's water
pipes by soldering, keeping
the connec ons at the water
heater cool with wet rags.
Residen al Gas Tankless Water Heater Use and Care Guide • 37
INSTALLATION
38 • Residen al Gas Tankless Water Heater Use and Care Guide
X3® Technology
WARNING! DO NOT operate water
heater un l either the X3® Cartridge
or Bypass cartridge has been
installed into the manifold located
on the underside of the water heater
cabinet. Failure to do so may result in
leaks and poten al property damage.
This water heater may be equipped
with X3® Scale Preven on Technology
to inhibit scale forma on within the
heat exchanger tubing of this unit.
Part of the X3® Technology’s an -
scale protec on comes from the
special X3® Cartridge media. The X3®
Cartridge must be installed into the
manifold located on the underside of
the heater cabinet prior to opera on
of the unit (shown as follows). X3®
Scale Preven on Technology reduces
the forma on of scale in the heat
exchanger, extending the opera ng
life of the unit in typical potable water
installa ons. Specifi c water condi ons
may impact the effi ciency of X3®, such
as excessive iron (max limit 0.3 mg/l
or 0.3 ppm) or manganese (max limit
0.05 mg/l or 0.05 ppm) levels.
X3
®
Cartridge
Bypass
Cartridge
Figure 36 - X3® & Bypass Cartridges
X3® Cartridge Installa on
1
Remove the plug assembly
installed into the manifold
located on the underside of
the water heater cabinet. Properly
dispose of plug assembly materials.
CAUTION! Water may be present
in the manifold. Place a bucket under
the water heater cabinet to collect
any residual water.
2
Locate the three (3) screws
provided in the hardware bag
on the top of the water
heater carton. Set the one
A
screw
(M4-12mm) and two
B
screws
(M4-25mm) aside in a safe place.
3
Locate the X3® Cartridge
provided with the water
heater.
NOTICE: Inspect O-rings for damage
or debris. Handle with care and verify
lubricant has been properly applied to
O-rings.
4
Insert the X3® Cartridge into
manifold and secure with the
one
A
screw and two
B
screws previously set aside in Step 2.
NOTICE: The X3® cartridge is keyed
to only install in one direc on. Align
the on the X3® cartridge with
the on the manifold (the bypass
cartridge is not keyed and will install
in either direc on). When inser ng
the X3® cartridge, push up un l the
screw holes align. Some resistance is
normal. See Figure 37 for reference.
Insert and snug all three screws by
hand. Use a screwdriver to ghten the
two
B
screws fi rst and lastly ghten
the one
A
screw. DO NOT use a drill
or impact driver to ghten the screws.
A BB
A
B
B
A
B
B
ALIGN
X3
®
CARTRIDGE
MANIFOLD
Figure 37 - X3® Cartridge Installa on
X3® Cartridge Removal
1
Disconnect power to the
water heater by unplugging it
or by turning off the circuit at
the breaker box.
2
Close the cold inlet water
valve.
3
Open all hot water taps in the
house. When the residual
water fl ow has ceased, close
all hot water taps.
NOTICE: Place a bucket under the
water heater cabinet to collect any
residual water.
4
Remove the two
B
screws
and the one
A
screw
securing the X3® Cartridge to
the manifold located on the underside
of the water heater cabinet. Set the
screws aside in a safe place for
re-installa on. Note the order of the
screws when removing them.
Reference Figure 37.
5
Pull down to remove the X3®
Cartridge from the water
heater.
NOTICE: The X3® Cartridge will be full
of water. Use cau on not to lt the
cartridge un l the water has been
drained.
Bypass Cartridge
If the water heater is an M model,
confi rm the Bypass cartridge has been
properly installed before opera ng
the water heater.
NOTICE: Bypass cartridge installs
the same way as the X3® cartridge,
however it is not keyed.
INSTALLATION
Residen al Gas Tankless Water Heater Use and Care Guide • 39
INSTALLATION
Pressure Relief Valve
WARNING! Hot water could be
released. Before opera ng the
pressure relief valve manually, check
that it will discharge in a safe place. If
water does not fl ow freely from the
end of the discharge pipe, turn the
gas supply and power OFF and call
a qualifi ed person to determine the
cause.
Refer to the pressure relief valve
manufacturer's instruc ons for
inspec on and maintenance
requirements.
The water heater has a high-
temperature shut-off switch built in
as a standard safety feature (called a
Hi-Limit switch), therefore a "pressure
only" relief valve is required.
An approved pressure relief valve
is supplied with X3® models. An
approved pressure relief valve shall be
fi eld supplied for M models.
The discharge piping for the pressure
relief valve must be directed so that
hot water cannot splash outward and
cause damage or personal injury.
A ach the discharge tube to the
pressure relief valve and run the
end of the tube to within 6 inches
(152 mm) from the fl oor for USA
installa ons and 12 inches
(305 mm) for Canadian installa ons.
This discharge tube must allow free
and complete drainage without any
restric ons.
If the pressure relief valve discharges
periodically, this may be due to
thermal expansion in a closed
water supply system. Contact the
water supplier or a local plumbing
professional on how to correct this
situa on.
WARNING! DO NOT plug the
pressure relief valve.
The pressure relief valve must be
manually operated periodically to
check for correct opera on. Before
opera ng the valve manually, check
that it will discharge in a place for
secure disposal.
NOTICE: No valve must be placed
between the pressure relief valve and
the water heater.
If another pressure relief valve is used
or needs to be replaced, it must meet
the following:
1
The pressure relief valve must
conform to ANSI Z21.22 or
CSA 4.4 and installa on must
follow local codes.
2
The discharge capacity must
be at least:
• 160,000 BTU/h for the TM-160 model
• 180,000 BTU/h for the TM-180 model
• 199,000 BTU/h for the TM-199 model
3
The pressure relief valve
needs to be rated for a
maximum of 150 psi.
6" (152 mm)
Maximum USA
Discharge Pipe
12" (305 mm)
Maximum Canada
Figure 38 - Discharge Pipe Clearance
Condensate Drain
Follow all code requirements of
the local authority on condensate
neutralizers and whether or not they
are required for installa on.
• Discharge condensate (acidic water)
in accordance with all local codes
and common safety prac ces.
• Install a minimum of 1/2 inch corro-
sion resistant pipe, such as PVC, for
the condensate drain line. DO NOT
use metal pipe.
• The condensate drain does not
require a trap.
• Maintain a downward slope on the
drain line(s), including installa ons
in which the drain is not directly
below the water heater.
• If a neutralizer is installed, a
fi eld-supplied overfl ow bypass fi t-
ng (tee/wye) is recommended.
• DO NOT connect the condensate
drain line directly to a condensate
pump.
• If the drain line is required to have
bends, ensure that there are no
kinks that will restrict the fl ow of
condensa on.
• The condensate drain is at atmo-
spheric pressure (non-pressurized)
and therefore must be allowed
to drain freely with gravity only.
Ensure that the condensate drain
tube is not plugged or blocked, and
ensure that it slopes downward to
allow condensate to fl ow freely. All
por ons of the condensate drain
(neutralizer and drain tube) must be
at a lower eleva on than the water
heater to prevent condensate water
from building up inside the heat
exchanger.
• Condensate cannot be eff ec ve-
ly neutralized if the neutralizer
elements have been completely
consumed. If this happens, conden-
sate will remain acidic and can pos-
sibly cause damage to items such
as pipes, concrete, etc., if drained
improperly.
• The actual life of the neutralizer may
vary, depending on the applica on
and usage. Replace the cartridge
when the condensate pH goes
below 6.0.
• All preventa ve measures and safety
prac ces must be adhered to when
draining condensate. The manufac-
turer will not be responsible for any
damage caused by condensate.
• A drain pan, or other means of
protec on against water damage, is
recommended to be installed under
the water heater in case of leaks.
Recircula on
When installing a recircula on pump,
care must be taken to properly size
the pump for the applica on. Sizing
must be performed by the installing
contractor or engineer. Below are
the requirements that need to be
followed when sizing:
• Size the recircula on pump to fl ow
no less than 2 gpm (7.6 L/min) and
no more than 4 gpm (15.1 L/min)
per heater ac va on. The manu-
facturer's suggested fl ow rate is 3
gpm (11.4 L/min). Refer to the water
heater's pressure drop chart on its
specifi ca on sheet for losses at oth-
er fl ow rates. See Table 15 below for
head loss through the water heater.
Table 15: Head Loss
Confi g. Flow Rate Head Loss
X3®
Models
3 gpm
(11.4 L/min)
25 .
(7.6 m)
M
Models
3 gpm
(11.4 L/min)
30 .
(9.1 m)
• The pump should be controlled
by a fi eld supplied aquastat with
immersion probe and an adjustable
diff eren al. The minimum suggested
diff eren al is 15°F (8.3°C).
NOTICE: Running the pump
con nuously will reduce the warranty
of the water heater.
• An air elimina on device is suggest-
ed to remove air from the piping
system. Air may cause the recircu-
la on pump to cavitate and may
reduce the water fl ow rate. These
items should be installed per the
manufacturer's instruc ons.
The installer will need to consider the
size of water tubing, material type,
and fi ngs when determining the
pressure drop of the system to size
the recircula on pump.
NOTICE: These characteris cs vary
for each tubing material of the same
nominal size. Refer to the water
tubing manufacturer for pressure
drop informa on that is needed to
size the recircula on pump. Check
with local codes and ordinances for
addi onal installa on requirements.
Point-of-use thermosta c mixing
valves may be used with tankless
water heaters. Consult with the
point-of-use thermosta c mixing valve
manufacturer for the appropriate
valve for the applica on. Refer to the
point-of-use thermosta c mixing valve
manufacturer for proper installa on
when recircula on is in use.
WARNING! To reduce the risk
of unusually hot water reaching
the fi xtures in the house, install
Thermosta c Mixing Valves at each
point-of-use.
NOTICE: Figure 39 on page 41
provides the manufacturer's
suggested piping layout for
recircula on. The installer must
properly install the system per
manufacturer's instruc ons and local
codes. Refer to the water heater
manufacturer's website for addi onal
layouts.
40 • Residen al Gas Tankless Water Heater Use and Care Guide
INSTALLATION
COLD
WATER
SUPPLY
EXPANSION
TANK
CHECK
VALVE
HOT WATER TO FIXTURES
BUILDING
RETURN
RECIRC
PUMP
TEMP.
PROBE
GAS
SUPPLY
SHUT-OFF
VALVE
CHECK
VALVE
SHUT-OFF
VALVE
SHUT-OFF
VALVE
SHUT-OFF
VALVE
G
S
SHUT-OFF
VA
LV
E
Figure 39 - Recommended Recircula on Diagram
Residen al Gas Tankless Water Heater Use and Care Guide • 41
INSTALLATION
Electrical Connec ons
WARNING! Working on an
energized circuit can result in severe
injury or death from electrical shock.
WARNING! The water heater must
be electrically grounded. DO NOT
a ach the ground wire to either the
gas or the water piping.
Power Supply
• The water heater requires a 120
VAC, 60 Hz electrical power supply
that is properly grounded.
• A proper disconnect (i.e., ON/OFF
switch, power plug, etc.) controlling
the main power to the water heater
must be provided for service rea-
sons. This disconnect must comply
with local codes.
• This water heater comes equipped
with a SJWT rated cord which is
weather resistant and rated for
outdoor use.
• The water heater can be hardwired
or plugged into an outlet with the
correct voltage (listed above) using
the supplied power cable already
a ached.
• The use of a surge protector is rec-
ommended in order to protect the
unit from power surges.
Plug-in Connec on
(Indoor & Outdoor Installs)
1
The water heater should be
plugged into a 120 VAC, 60 Hz
ground electrical outlet.
Hardwired Connec on
(Indoor & Outdoor Installs)
NOTICE: Follow the steps below if the
power supply must be hardwired to
the water heater. Otherwise, you may
skip this sec on.
1
Remove and keep the two
screws securing the front
cover. Remove the cover.
2
Locate the system power cord
using Figure 40. Cut the wires
at the loca on shown in
Figure 40.
Figure 40 - System power cord cut loca on.
3
Remove the screws securing
the power cord to the bo om
of the water heater.
4
Remove the power cord from
the bo om of the water
heater and install a strain
relief connector in the opening.
5
Make the electrical
connec on to the water
heater. Follow the electrical
code requirements of the local
authority having jurisdic on. In the
absence of local codes, follow the
current edi on of the Na onal
Electrical Code ANSI/NFPA 70 in the
U.S. or the current edi on of CSA
C22.1 Canadian Electrical Code Part 1
in Canada.
6
Verify all electrical
connec ons are secure.
7
Replace the front cover and
secure with the two screws
previously removed. Turn on
power to the water heater.
8
Follow the instruc ons in the
Ge ng Started sec on of this
manual.
42 • Residen al Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Accessory Connec ons
This system supports up to three
accessories connected in series.
NOTICE: If mul ple water heaters
are used in a Cascade System, all
accessories must be connected in
series to the parent unit.
Follow the accessory kit instruc ons
to access the control board.
Each accessory has both a fi ve-pin
female connector and a sec on of
cable with a fi ve-pin male connector
on the end (see Figure 41). The male
connector connects to the control
board or to the next accessory in the
series. The fi ve-pin female connector
allows another accessory to connect
and create a series. Reference the
fi gure below when crea ng a series
of accessories. If the length of the
accessory cord is not long enough,
communica on cables can be
purchased to extend the length.
These cables are available in 10 .
(3 m) and 32 . (10 m) lengths.
Connect the single fi ve-pin connector
on the communica on cable to the
fi ve-pin female connector on the
accessory. The maximum wire length
from the water heater (the Parent unit
in a Cascade System) to the furthest
accessory is 100 . (30 m).
Residen al Gas Tankless Water Heater Use and Care Guide • 43
INSTALLATION
Wi-Fi Module
Wall
Printed Circuit
Board
Remote
Temperature
Controller
Accessory 5
Pin Female
Accessory 5
Pin Male
Figure 41 - Accessories Installed in Series
44 • Residen al Gas Tankless Water Heater Use and Care Guide
Cascade System
The Cascade System allows up to 12
heaters of the same input to be linked
in a Parent/Child confi gura on. Do
not link heaters of diff erent input
rates together.
The Cascade System will ac vate
heaters based on the system fl ow
rate demand. When system demand
increases or decreases, the cascade
system will ac vate/deac vate
heaters as needed to balance fl ow
through the heaters.
The Parent heater determines when
to ac vate/deac vate heaters. The
order of heater ac va on is set by
the Parent heater and will sequence
the heaters in order from the least
combus on hours to the most. This
allows for even opera on of all the
water heaters in the cascade system.
The heaters will deac vate in the
reverse order that they are ac vated,
meaning if Child Heater 11 was the
last to turn on, it will be the fi rst
to turn off when system demand
decreases. The Parent heater will
reorder the sequence on a weekly
basis.
The new sequence of ac va on will
start with the heater that has the
least combus on hours to the most.
Each heater will ac vate based on
predetermined fl ow rate factors.
These factors vary based on heater
model.
If any child heater encounters an error
code, the cascade system will bypass
that heater and con nue to operate.
If the Parent heater loses power, then
the cascade system deac vates. The
user will need to change the se ngs
of one of the other heaters to be the
Parent or resolve the issue of the
Parent heater.
WARNING! Working on an
energized circuit can result in severe
injury or death from electrical shock.
1
The Cascade system should
be confi gured with the Parent
water heater as either the
fi rst or last in the series of water
heaters connected to the cold water
supply. The Child units will follow
sequen ally. See Figure 44.
2
Before proceeding,
disconnect electrical power
to all water heaters in the
Cascade confi gura on.
3
Remove the front covers and
keep the two screws from
both the Parent and Child
water heaters for re-installa on.
4
Remove the two screws (top
and bo om) securing the
control panel to the Parent
water heater. The control panel is
located on the bo om right side of
the water heater as shown in Figure
42.
Remove
Screws (2x)
Control Panel for
Printed Circuit Board
ON/OFF
W
N
P
SETTING
Figure 42 - Control Panel Loca on
5
Gently slide control panel out
from the Parent water heater
to gain access to the Printed
Circuit Board (PCB). Proceed with
cau on and DO NOT disconnect wires
from PCB.
6
Use Figure 43 to locate the
rubber access grommet on
the bo om of the water
heater. Route the single harness end
of the Cascade Linking Cable through
the bo om and around to the circuit
board.
NOTICE: The cable should be routed
under the circuit board assembly to
prevent strain to the wiring harness.
Rubber Grommet
Figure 43 - Bo om of water heater - Grommet
7
Use Figure 44 as a reference
to locate the connec on
point for the Parent Cascade
Unit. Use the single harness end of
the Cascade Linking Cable to make the
ini al connec on.
8
Follow steps 4-6 to route the
double harness end of the
Cascade Linking Cable to the
printed circuit board on the fi rst Child
water heater.
9
If more than one Child water
heater is used then route the
single harness end of the
second Cascade Linking Cable through
the rubber grommet on the bo om of
the fi rst Child water heater and
connect it to the open harness on the
fi rst Cascade Linking Cable as shown
in Figure 44.
INSTALLATION
Residen al Gas Tankless Water Heater Use and Care Guide • 45
10
Once all connec ons are
made, the water heaters
must be assigned their
posi on in the system. Turn on the
power supply to all of the water
heaters, making sure there is no water
fl ow.
11
On the Parent water heater
simultaneously press and
hold the "SETTING" and "UP"
bu ons un l C00 appears. See Table
23 on page 52.
12
Press the UP arrow bu on to
reach the C13 op on, then
press the "SETTING" bu on
to enter that op on.
NOTICE: C13 defi nes the number
of Child water heaters that will be
connected to the parent unit.
Enter the number of Child water
heaters a ached to the parent water
heater and press the "SETTING"
bu on to load the number to
memory. For example, if the system
consists of four total water heaters,
then enter 3 for three child heaters
into C13. Press the "SETTING" bu on
again to return to normal opera on.
13
A er the Parent water heater
is confi gured, the Child water
heaters must be confi gured.
Perform the following steps on each
Child water heater.
14
On each Child unit’s UIM,
press and hold both the
"SETTING" and "UP" bu ons
un l C00 appears.
15
Press the UP arrow bu on to
reach the C14 op on, then
press the "SETTING" bu on
to enter that op on.
NOTICE: C14 defi nes the number
assigned to each Child water heater
connected to the parent water heater.
16
Enter number 2 for the fi rst
Child water heater and press
the "SETTING" bu on to load
the number to memory. Repeat this
step assigning a sequen al number at
each addi onal Child water heater.
17
Press and hold the "SETTING"
bu on again to return to
normal opera on.
NOTICE: A maximum 11 Child water
heaters can be connected to a
Cascade System of 12 total water
heaters.
18
Verify all electrical
connec ons and conduit
connec ons are secure.
19
Follow the instruc ons in the
Ge ng Started sec on of this
manual.
INSTALLATION
BUILDING
RETURN
PARENT UNIT
CWS
HWS
GAS
CHILD UNIT #1 CHILD UNIT #2
Double
Harness End
Child Unit PCB
Single
Harness
End
Single
Harness
End
Parent Unit PCB
Par
ent
Un
it
PCB
3-Pin Connector
Figure 44 - Mul Unit Cascade Confi gura on
46 • Residen al Gas Tankless Water Heater Use and Care Guide
FOR YOUR SAFETY,
READ BEFORE
OPERATING
WARNING! IF YOU SMELL GAS:
• DO NOT try start the water heater.
• DO NOT touch any electric switches.
• DO NOT use any phone in your
building.
• Immediately call your gas supplier
from a neighbor's phone. Follow the
gas supplier's instruc ons.
• If you cannot reach your gas suppli-
er, call the fi re department.
• Failure to observe these warnings
could lead to fi re or an explosion,
resul ng in severe injury or death.
ᅚ Check the GAS and WATER CON-
NECTIONS for leaks before fi ring
unit for the fi rst me.
ᅚ Open the main gas supply valve to
the unit using only your hand to
avoid any spark. Never use tools. If
the knob will not turn by hand,
DO NOT try to force it; call a qual-
ifi ed service technician. Forced re-
pair may result in a fi re or explosion
due to gas leaks.
ᅚ Be sure to check for the presence
of leaking gas toward the bo om
of the unit because some gases
are heavier than air and may se le
towards the fl oor.
ᅚ Check the GAS PRESSURE. Refer to
the "Gas Supply and Gas Pipe Siz-
ing" sec on star ng on page 35.
ᅚ Check for PROPER VENTING and
COMBUSTIBLE AIR to the water
heater.
ᅚ Purge the GAS and WATER LINES to
remove any air pockets.
ᅚ DO NOT use this appliance if any
part has been under water. Immedi-
ately contact a qualifi ed installer or
service agency to replace a fl ooded
water heater. DO NOT a empt to
repair the unit! It must be replaced!
Start-Up Instruc ons
Read and understand these direc ons
thoroughly before a emp ng to
start-up the water heater. Make sure
the water is plumbed correctly before
a emp ng to start-up the water
heater. Check the ra ng plate on
the right side of the water heater to
ensure the correct gas type.
DO NOT use this water heater with
any gas other than the one listed
on the ra ng plate. If you have any
ques ons or doubts, consult your gas
supplier or gas u lity company.
NOTICE: A newly installed water
heater will have air in the gas line. It
may take several a empts to clear all
the air from the gas line.
1
Make sure the manual gas
valve for the water heater's
supply line is ON.
2
Plug the water heater into a
grounded 120 VAC outlet, or
ac vate the breaker/
disconnect, if the water heater is
hardwired.
3
The user interface will display
the current temperature
se ng. The default is 120°F
(49°C).
4
To change the set point
temperature, press the "UP"
or "DOWN" bu on to raise or
lower the outlet temperature. See the
"Temperature Se ngs" sec on on
page 49.
5
To set the heater to the
appropriate eleva on, vent
size and vent length, see
"Confi gura on Mode (C Mode)"
star ng on page 50.
Shut-Down Instruc ons
Press the "ON/OFF" bu on and wait
for the display to shut off .
NOTICE: The power bu on on the
water heater and remote DOES NOT
disconnect power to the water heater.
You must physically disconnect power
to the water heater.
Emergency Shut-Down
Should overhea ng occur or the gas
supply fail to shut off , follow these
steps:
1
Turn OFF the gas supply to
the water heater at the
manual shut-off valve.
2
Press the "ON/OFF" bu on
on the water heater.
3
Disconnect power to the
water heater by unplugging it
or by turning off the circuit at
the breaker box, as appropriate.
4
Call a qualifi ed person
(licensed plumber, authorized
gas company personnel, or
authorized service technician) for
assistance.
OPERATION
Figure 45 - Ligh ng Instruc ons
Residen al Gas Tankless Water Heater Use and Care Guide • 47
OPERATION
48 • Residen al Gas Tankless Water Heater Use and Care Guide
Display Overview
ON/OFF
DOWN
UP SETTING
E
F
G
H
B
A
C
D
Figure 46 - User Interface Display Diagram
Table 16: User Interface Display
Item Descrip on
A Water Flow Detected
B Flame Detected
C Up Bu on
D Down Bu on
E Display
F Standby Mode
GSe ng Bu on
H Opera on ON/OFF Bu on
OPERATION
Residen al Gas Tankless Water Heater Use and Care Guide • 49
OPERATION
Temperature Se ngs
With the installa on steps completed, you may adjust the water heater's temperature se ng if desired. The water temperature
set point is factory set to 120°F (49°C). The temperature set point may be increased or decreased by simply pressing the
"UP" bu on or the "DOWN" bu on. To set the water heater to a temperature above 125°F (52°C), follow the procedure as
outlined in Table 17:
Table 17: Set Temperature Above 125°F (52°C)
Opera on Screen on the Controller (Built-in & Remote)
1. Turn on the 120 VAC power supply to the unit.
2.
Press the "ON/OFF" bu on on the controller in order to turn the
controller on.
ON/OFF
3.
The set point temperature will display as shown in the picture on
the right (Example: 120°F).
4.
WARNING! Higher temperatures increase the risk of scalding,
but even at 120°F (49°C), hot water can scald (page 10).
Press and hold the "SETTING" bu on for 5 seconds to access the
water heater Adjustment Mode (A Mode).
LONG PRESS
SETTING
5.
The display will fl ash between code "A00" and the current set
temperature. Short press the "SETTING" bu on to access the
temperature se ng. The temperature only will fl ash.
SHORT PRESS
SETTING
6.
Press the "UP" bu on and the "DOWN" bu on to select the
desired set point temperature. See Table 18 below for available
set point temperatures.
UP
DOWN
7. Short press the "SETTING" bu on again to execute the change.
SHORT PRESS
SETTING
8.
Press and hold the "SETTING" bu on for 5 seconds to return the
display to normal opera on. The new temperature set point will
appear (Example: 130°F).
Table 18: Water Heater Temperature Set Points
°F 100 102 104 106 108 110 115 120* 125 130 135 140
°C 38 39 40 41 42 43 46 49* 52 54 57 60
*Factory se ng (Default): 120°F (49°C).
50 • Residen al Gas Tankless Water Heater Use and Care Guide
OPERATION
Confi gura on Mode (C Mode)
You can confi gure the water heater to accommodate your applica on from C Mode. Follow the procedure below to access
C Mode and to properly confi gure the water heater for your applica on:
1. Press and hold the "UP" bu on and the "SETTING" bu on for 5 seconds to access C Mode.
2. Press the "UP" bu on or the "DOWN" bu on to search for the desired C Code.
3. If applicable, press the "SETTING" bu on to adjust the value of the C Code using the "UP" and "DOWN" bu ons. The value
will fl ash.
4. Press the "SETTING" bu on again to confi rm the new value selected is correct.
5. Press and hold the "UP" bu on and the "DOWN" bu on for 5 seconds to return the display to normal opera on.
Table 19: C Mode Al tude Se ngs (C01)
Code Descrip on Se ng Confi gura on Op ons
C01 Al tude Se ngs
0 0 to 2,000 . (0 to 610 m) Eleva on
1 2,001 to 5,400 . (611 to 1,645 m) Eleva on*
2 5,401 to 7,800 . (1,646 to 2,377 m) Eleva on*
*High al tude vent se ngs above 2000 (609 m) feet will impact some vent length se ngs. See Table 22.
Table 20: C Vent Size (CO8)
Code Descrip on Se ng Confi gura on Op ons
C08 Vent Size
2 2 Inch
3 3 Inch
Vent Length Confi gura on
Before opera ng the water heater, you must determine the correct vent length se ng for your applica on.
Reference Table 8 (page 22) and Tables 10 & 11 (pages 26-27) to calculate the total vent length for your applica on:
Example:
Ven la on Component Type Equivalent Length
The example to the le assumes a
Power Direct Vent installa on with
2 inch Polypropylene ven ng at sea level.
Using Table 21 on the following page, the
appropriate CO2 se ng for 24 feet
(7.2 m) of ven ng is
C02 = 2.
Elbows (Table 8) (1x) 87° Elbow 3 . (0.9 m)
Termina on (Tables 9 & 10) Polypropylene (2" Low Profi le) 6 . (1.8 m)
Horizontal Vent Run Polypropylene 12 . (3.7 m)
Ver cal Vent Run Polypropylene 3 . (0.9 m)
Total Vent Length: 24 . (7.3 m)
Your Applica on:
Ven la on Component Type Equivalent Length
Use your total length and the informa on
found in Tables 21 or 22 (depending
on eleva on) on the following page to
determine the correct vent length se ng
based on your applica on.
Elbows (Table 8)
Termina on (Tables 9 & 10)
Horizontal Vent Run
Ver cal Vent Run
Total Vent Length:
Residen al Gas Tankless Water Heater Use and Care Guide • 51
OPERATION
Table 21: C Mode Vent Length Confi gura on (C02) for 0-2,000 . (0 to 610 m) Eleva on
Code
Vent
Material
Vent
Size
Vent
Confi gura on
Controller Se ng
C02 = 0 C02 = 1 C02 = 2 C02 = 3 C02 = 4
C02
PVC
2 Inch
PDV
4-7 .
(1.2-2.1 m)
8-18 .
(2.2-5.5 m)
19-31 .
(5.6-9.5 m)
32-44 .
(9.6-13.4 m)
45-50 .
(13.5-15.2 m)
PV
4-12 .
(1.2-3.7 m)
13-25 .
(3.8-7.6 m)
26-50 .
(7.7-15.2 m)
3 Inch
PDV
4-20 .
(1.2-6.1 m)
21-60 .
(6.2-18.3 m)
61-140 .
(18.4-42.7 m)
141-150 .
(42.8-45.7 m)
PV
4-25 .
(1.2-7.6 m)
26-80 .
(7.7-24.4 m)
81-150 .
(24.5-45.7 m)
PP
2 Inch
PDV
4-9 .
(1.2-2.7m)
10-21 .
(2.8-6.4 m)
22-39 .
(6.5-11.9 m)
40-50 .
(12.0-15.2 m)
PV
4-12 .
(1.2-3.7 m)
13-30 .
(3.8-9.1 m)
31-50 .
(9.2-15.2 m)
3 Inch
PDV
4-20 .
(1.2-6.1 m)
21-60 .
(6.2-18.3 m)
61-140 .
(18.4-42.7 m)
141-150 .
(42.8-45.7 m)
PV
4-25 .
(1.2-7.6 m)
26-80 .
(7.7-24.4 m)
81-150 .
(24.5-45.7 m)
(PVC = Polyvinyl Chloride, PP = Polypropylene, PDV = Power Direct Vent, PV= Power Vent)
Table 22: C Mode Vent Length Confi gura on (C02) for 2,001-7800 . (611 to 2,377 m) Eleva on
Code
Vent
Material
Vent
Size
Vent
Confi gura on
Controller Se ng
C02 = 0 C02 = 1 C02 = 2 C02 = 3 C02 = 4
C02
PVC
2 Inch
PDV
4-7 .
(1.2-2.1 m)
8-18 .
(2.2-5.5 m)
19-31 .
(5.6-9.5 m)
32-44 .
(9.6-13.4 m)
45-50 .
(13.5-15.2 m)
PV
4-12 .
(1.2-3.7 m)
13-25 .
(3.8-7.6 m)
26-42
(7.7-12.8 m)
43-50 .
(12.9-15.2 m)
3 Inch
PDV
4-25 .
(1.2-7.6 m)
26-70 .
(7.7-21.3 m)
71-150 .
(21.4-45.7 m
PV
4-35 .
(1.2-10.7 m)
36-120 .
(10.8-36.6 m)
121-150 .
(36.7-45.7 m)
PP
2 Inch
PDV
4-9 .
(1.2-2.7m)
10-21 .
(2.8-6.4 m)
22-39 .
(6.5-11.9 m)
40-50 .
(12.0-15.2 m)
PV
4-12 .
(1.2-3.7 m)
13-30 .
(3.8-9.1 m)
31-50 .
(9.2-15.2 m)
3 Inch
PDV
4-25 .
(1.2-7.6 m)
26-70 .
(7.7-21.3 m)
71-150 .
(21.4-45.7 m
PV
4-35 .
(1.2-10.7 m)
36-120 .
(10.8-36.6 m)
121-150 .
(36.7-45.7 m)
(PVC = Polyvinyl Chloride, PP = Polypropylene, PDV = Power Direct Vent, PV= Power Vent)
52 • Residen al Gas Tankless Water Heater Use and Care Guide
Table 23: C Mode Cascade System (C13 & C14)
Code Descrip on Se ng Confi gura on Op ons
C13 Number of Child Units in Cascade System
0:
1-11:
No Cascade System (default).
Iden fy number of Child Units. This ac vates the Cascade System.
C14 Cascade System Heater ID Number
1:
2-12
Parent Heater (default).
Individually set each Child Unit per user preference.
Unit Conversion Mode
Units of measure can be changed from Imperial to Metric and vice versa. For example, temperature can be changed from
°F to °C. Flow rate will also change from gallons per minute to liters per minute when this se ng is changed. Follow this
procedure to change this se ng:
Table 24: Convert Units
Opera on Screen on the Controller (Built-in & Remote)
1. Turn on the 120 VAC power supply to the unit.
2.
Press the "ON/OFF" bu on on the controller in order to turn the
controller on.
ON/OFF
3.
The set point temperature will display as shown in the picture on
the right (Example: 120°F).
4.
Press and hold the "SETTING" bu on for 5 seconds to access the
water heater Adjustment Mode (A Mode).
LONG PRESS
SETTING
5.
The display will fl ash between code "A00" and the current set
temperature. Press the "UP" or "DOWN" bu on once and the
display will show code "A01." Short press the "SETTING" bu on
to show the current temperature se ng. The temperature will
fl ash.
SHORT PRESS
SETTING
6.
Press the "UP" bu on and the "DOWN" bu on to alternate
between Fahrenheit and Celsius.
UP
DOWN
7. Short press the "SETTING" bu on again to execute the change.
SHORT PRESS
SETTING
8.
Long press the "SETTING" to return the display to normal
opera on. The new temperature set point will appear in the
selected unit (Example: 49°C).
OPERATION
Residen al Gas Tankless Water Heater Use and Care Guide • 53
MAINTENANCE
Regular Maintenance
WARNING! Turn OFF the electrical
power supply and close the manual
gas shut-off valve and the manual
water control valve before servicing.
Failure to do so could result in
serious personal injury or death.
Rou ne maintenance will help your
water heater last longer and work
be er. Failure to perform required or
recommended maintenance may void
the warranty. If you cannot perform
these rou ne maintenance tasks
yourself, contact a qualifi ed person:
The manufacturer recommends
having the unit checked once a year or
as necessary by a licensed technician
or qualifi ed person. If repairs are
needed, any repairs should be done
by a licensed technician.
• Clean the cold-water inlet fi lter.
• The intake and ven ng system
should be checked annually for any
leaks, corrosion, blockages, or dam-
age. Replace any damaged sec on
of ven ng and clear any blockage.
• The ven ng system should be
checked annually for any leaks,
corrosion, blockages or damage.
Replace any damaged sec on of
ven ng and clear any blockages.
• Keep the area around the water
heater and termina ons clear. Reg-
ularly ensure that the area around
the water heater, vent termina on,
and air intake is free from dust,
debris, and other contaminants.
Remove any combus ble materials,
gasoline, fl ammable vapors, and
liquids.
• If the pressure relief valve discharg-
es periodically, it may be due to
thermal expansion in a closed water
supply system. Contact the water
supplier or local plumbing inspector
on how to correct this situa on.
• The pressure relief valve must be
manually operated periodically to
check for correct opera on. Before
opera ng the valve manually, check
that it will discharge in a place for
secure disposal.
• The condensate drain system must
be inspected regularly that it drains
properly in accordance with local
codes or the manufacturer's instruc-
ons.
• The burner should be checked annu-
ally for dust, lint, grease or dirt.
• Visually check the burner fl ames
through the burner window (sight
glass) on the burner assembly. The
burner assembly is located in the
middle of the water heater. A prop-
erly opera ng burner should pro-
duce clear, blue, stable fl ames. The
fl ames should not be li ing above
the burner. Contaminated air may
cause a discolored fl ame. Contact a
qualifi ed technician if the fl ame is
not sa sfactory. See Figure 47 below
for burner fl ame reference.
Blue Flame
Satisfactory
Flame lifting
above the
burner
Unsatisfactory
Figure 47 - Check Burner Flames
Freeze Protec on
System
This unit comes equipped with
hea ng blocks to protect it from
damage associated with freezing. The
auto-fi re mode ac vates the burner
for a short period of me.
For this freeze protec on system to
operate, there must be electrical
power to the unit. Damage to the
heat exchanger caused by freezing
temperatures due to power loss is
not covered under the warranty. In
cases where power losses can occur,
consider the use of a backup power
supply.
It is the installer's responsibility
to be aware of freezing issues and
take all preventa ve measures. The
manufacturer will not be responsible
for any damage to the heat exchanger
as a result of freezing.
NOTICE: Only pipes within the water
heater are protected by the freeze
protec on system. Any water pipes
(hot or cold) located outside the
unit will not be protected. Properly
protect and insulate these pipes from
freezing. See “Available Accessories”
on page 15 for the Cartridge Freeze
Protec on Kit. This kit is available for
both the X3® Models and M Models.
If you will not be using your heater
for a long period of me or power has
been lost during freezing condi ons:
1
Completely drain the water
out of the unit. See the "Unit
Draining & Power Outage
(Freeze Protec on)" sec on on page
54.
2
Disconnect power to your
water heater.
54 • Residen al Gas Tankless Water Heater Use and Care Guide
Unit Draining &
Power Outage (Freeze
Protec on)
1
Close the manual gas shut-off
valve.
2
Disconnect power to the
water heater by unplugging it
or by turning off the circuit at
the breaker box.
3
Close the cold inlet water
valve.
4
Open all hot water taps in the
house. When the residual
water fl ow has ceased, close
all hot water taps.
5
Drain the X3® (or Bypass)
Cartridge: Have a bucket or
pan to catch water from the
X3® Cartridge. To remove the X3®
Cartridge, remove and keep the 3
screws securing the cartridge in place.
Pull down to remove it from the water
heater. Empty the water out of the
cartridge into the bucket.
6
Wait a few minutes to ensure
all water has completely
drained from the unit.
7
Keep the cold water valve
closed. Keep the gas valve
closed. Keep supply power
disconnected.
8
To restore the unit to
opera on, reinstall the X3®
Cartridge with 3 screws
removed earlier. For detailed
instruc ons see “X3® Cartridge
Installa on” on page 38.
9
Open the cold inlet water
valve. Check all water
connec ons for leaks. If leaks
are found, shut off the cold water
inlet valve and immediately fi x any
leaks. If no leaks are present proceed
to the next step.
10
Reconnect power to the
water heater.
11
Open the manual gas shut-off
to the water heater.
12
If the set temperature is not
displayed, press the ON/OFF
bu on.
NOTICE: If any errors occur, shut off
the water immediately.
Discharge Condensate
1
Inspect the drain lines for any
clogs and clear.
2
Check the drain lines for a
downward slope. Correct any
lines where water does not
drain freely.
3
Inspect the built-in
condensate trap drain lines
for debris. Disconnect the
lines and drain to remove the debris.
4
If a neutralizer is installed,
check the pH level. Replace
the neutralizer if the pH of
the outlet water is below 6.0.
5
If this fi lter is clogged, water
will not be supplied to the
water heater properly.
Inlet Water Filter
1
Close the manual gas shut-off
valve.
2
Disconnect power to the
water heater by unplugging it
or by turning off the circuit at
the breaker box.
3
Close the inlet water valve.
4
Open all hot water taps in the
house. When the residual
water fl ow has ceased, close
all hot water taps.
5
Drain the X3® (or Bypass)
Cartridge: Have a bucket or
pan to catch water from the
X3® Cartridge. To remove the X3®
Cartridge, remove and keep the 3
screws securing the cartridge in place.
Pull down to remove it from the water
heater. Empty the water out of the
cartridge into the bucket.
6
Wait a few minutes to ensure
all water has completely
drained from the unit.
7
Unscrew the inlet water fi lter
and remove it from the water
heater.
8
Clean the fi lter: Check the
water fi lter located within the
cold inlet. With a ny brush,
clean the water fi lter of any debris
which may have accumulated.
9
Screw the inlet water fi lter
back into place. Hand- ghten
only.
NOTICE: Handle with care and verify
the O-ring is not dirty or damaged.
10
To restore the unit to
opera on, reinstall the X3®
Cartridge with 3 screws
removed earlier. For detailed
instruc ons see “X3® Cartridge
Installa on” on page 38.
11
Turn ON the cold water
supply to the water heater at
the cold inlet valve. The
system will fully pressurize and any
leaks at water connec ons will be
apparent. Correct any leaks
immediately.
12
Turn ON the gas supply to the
water heater at the manual
gas shut off valve.
13
Restore power to the water
heater. The water heater is
now ready for opera on.
MAINTENANCE
Residen al Gas Tankless Water Heater Use and Care Guide • 55
TROUBLESHOOTING
General Troubleshoo ng
If the water heater is experiencing issues, please check the following. A er checking, consult with a qualifi ed person.
Table 25: Troubleshoo ng Chart
Problem Solu ons
Temperature and Amount of Hot Water
It takes a long me to get hot water
at the fi xtures.
• The mes it takes to deliver hot water from the water heater to your fi xtures
depends on the length of piping between the two. The longer the distance or
the bigger the pipes, the longer it will take to get hot water.
• If you would like to receive hot water to your fi xtures more quickly, you may
want to consider a hot water recircula on system.
The water is not hot enough.
• Check the set temperature of the water heater and adjust, if necessary.
• Check cross plumbing between the cold water lines and hot water lines.
• Is the gas supply valve open fully?
• Is the gas line sized properly?
• Is the gas supply pressure suffi cient?
• Check if the Point-of-Use mixing valves are set correctly if they are installed.
The water is too hot. • Is the set point temperature set too high?
The hot water is not available when
a fi xture is opened.
• Make sure the unit has 120 VAC, 60 Hz power supply and power frequency is
set to 60 hz.
• Verify the opera on se ng is ON by viewing the UIM. If the set temperature is
showing or you press the UP arrow to display the set temperature, then the op-
era on se ng is ON. If the display is blank and nothing appears when pressing
the UP bu on, then the opera on state is set to OFF. Press the ON/OFF bu on
to ac vate the heater. The set temperature will display when set to ON.
• Is the gas supply valve open fully and within the allowable gas pressure range?
• Is the water supply valve fully open?
• Is the fi lter on the cold water inlet clean?
• Is the hot water fi xture suffi ciently open to draw at least 0.4 GPM
(1.5 L/min) through the water heater?
• Is the unit frozen?
The hot water runs cold and stays
cold.
• Is the fl ow rate enough to keep the water heater running?
• If there is a recircula on system installed, does the recircula on line have
enough check valves?
• Is the gas supply valve fully open?
• Is the fi lter on the cold water inlet clean?
• Are the fi xtures clean of debris and obstruc ons?
Fluctua on in hot water
temperature.
• Is the fi lter on the cold water inlet clean?
• Is the gas line sized properly?
• Is the gas supply pressure suffi cient?
• Check for cross connec on between cold water lines and hot water lines.
56 • Residen al Gas Tankless Water Heater Use and Care Guide
Table 25: Troubleshoo ng Chart
Problem Solu ons
Water Heater
Unit does not ignite when water
goes through the unit.
• Is the fl ow rate over 0.4 GPM (1.5 L/min)?
• Check the fi lter on the cold water inlet.
• Check for reverse connec ons and cross connec on.
• If you use the remote controller and/or built-in controller, is the power bu on
turned on?
• Check if the inlet water temperature is too high. If it is too close to the set tem-
perature, the water heater will not ac vate.
The fan motor is s ll spinning a er
opera on has stopped.
• This is normal. A er opera on has stopped, the fan motor keeps running to
re-ignite quickly, as well as purge all the exhaust gas out of the fl ue.
Unit sounds abnormal while in
opera on.
• Contact Technical Support Department.
TROUBLESHOOTING
Residen al Gas Tankless Water Heater Use and Care Guide • 57
TROUBLESHOOTING
Error Codes
The water heater has self-diagnos c
func ons for safety and convenience
when troubleshoo ng.
If there is a problem with the
installa on or the unit, the error code
associated with that failure will be
displayed on the built-in controller or
remote controller.
Consult the Table 26 on the following
pages for the descrip on of each error
code.
Single Unit Installa on
(Example)
If your water heater has the "E002"
error code (which signifi es a high limit
break):
• Indicator on the built-in and/or
remote controller will display "E002"
on the screen.
Figure 48 - Single Unit Error Code Example
Cascade System
(Example)
Error codes will be displayed
diff erently with units installed within
a Cascade System, not only to show
what the error code is, but to also
indicate which unit within the system
has the error code. Below is a sample
of how the error code "E002" is
displayed in a Cascade System.
If Unit #2 has the "E002" error code
(which signifi es a high limit break):
• Indicator on the built-in and/or
remote controller of Parent unit will
intermi ently fl ash "E002" and "2."
Figure 49 - Cascade System Error Code Example
(Parent Unit)
• Child unit #2 will intermi ently fl ash
"E002"on the display.
Figure 50 - Cascade System Error Code Example
(Child Unit)
• Child unit #3 & #4 will not display
anything, as the error code does not
pertain to them.
58 • Residen al Gas Tankless Water Heater Use and Care Guide
Fault Analysis of Error Codes
If the water heater is displaying an error code, please check the following. A er checking, consult with the manufacturer.
Table 26: Error Code Fault Analysis
Error
Code
Error Descrip on Procedure
E002 High Limit Break
Manual Hi-Limit Switch located on heat exchanger tripped. Check Hi-limit switch
for proper opera on. Pressing the reset bu on (center of the switch), will reset the
Hi-limit switch.
NOTICE: If the Hi-Limit switch has tripped, you will hear and feel it click when
rese ng it. If the high limit switch con nues to trip, contact a qualifi ed service
technician.
E006
PCB Hardware Fault - AD
Converter Fault
Check PCB wiring for loose, damaged or cut wires/connectors. Correct any loose
connec on and replace any damaged wires/connectors. If all wires/connectors are
intact, replace the PCB.
E010 Frequency Fault
PCB has detected an incorrect power supply frequency. Note the default frequency
is 60 Hz. See instruc ons on page 50 to access C Mode. Confi rm C07 displays 60. If
the se ng is correct and the error s ll occurs, contact a qualifi ed service technician.
E011
PCB Hardware Fault - Memory
Error
The water heater will con nue to operate while this error code is fl ashing. If this
heater is part of a cascade system, then the system will be aff ected based on the
heater’s se ng.
• Parent Heater: The cascade system will not operate. Remove this heater from the
cascade system and set a diff erent heater as the Parent.
• Child Heater: This heater will not operate. The rest of the cascade system will
con nue to run.
E036 Flame Failure
WARNING! Working on an energized circuit can result in severe injury or death
from electrical shock.
Check the fl ame sensor wire for a short or disconnec on. Correct any loose
connec on and replace any damaged wire/connector. If the error s ll occurs,
contact a qualifi ed service technician.
E037 False Flame Detec on.
WARNING! Working on an energized circuit can result in severe injury or death
from electrical shock.
1. Check for a visible fl ame through the sight glass while water is not running
through the water heater. If error s ll occurs, immediately shut off the water heater
and contact a qualifi ed service technician.
2. Check the fl ame sensor wire for a short or disconnec on. Correct any loose
connec on and replace any damaged wire/connector. If the error s ll occurs,
contact a qualifi ed service technician.
TROUBLESHOOTING
Residen al Gas Tankless Water Heater Use and Care Guide • 59
TROUBLESHOOTING
Table 26: Error Code Fault Analysis
Error
Code
Error Descrip on Procedure
E038 Igni on Failure
WARNING! Working on an energized circuit can result in severe injury or death
from electrical shock.
1. Check for a visible fl ame through the sight glass.
2. Check the fl ame sensor wire for a short or disconnec on. Correct any loose
connec on and replace any damaged wire/connector. If the error s ll occurs,
contact a qualifi ed service technician.
E041 Outlet Water Over-temp
1. Verify the thermistor reading with the water outlet temperature.
2. Remove the outlet thermistor (do not lose the O-ring) and check for any dirt or
debris. Clean with an Emery cloth. If the thermistor is damaged, replace it. If the
error s ll occurs, contact a qualifi ed service technician.
E049 Exhaust Thermistor Failure
1. Remove the thermistor (do not lose the O-ring) and check for any dirt or debris.
Clean with an Emory cloth. If the thermistor is damaged, replace it.
2. Check the Thermistor sensor wire for a short or disconnec on. Correct any
loose connec on and replace any damaged wire/connector. If the error s ll occurs,
contact a qualifi ed service technician.
E050 Inlet Thermistor Failure
1. Remove the thermistor (do not lose the O-ring) and check for any dirt or debris.
Clean with an Emory cloth. If the thermistor is damaged, replace it.
2. Check the Thermistor sensor wire for a short or disconnec on. Correct any
loose connec on and replace any damaged wire/connector. If the error s ll occurs,
contact a qualifi ed service technician.
E051 Outlet Thermistor Failure
1. Remove the thermistor (do not lose the O-ring) and check for any dirt or debris.
Clean with an Emory cloth. If the thermistor is damaged, replace it.
2. Check the Thermistor sensor wire for a short or disconnec on. Correct any
loose connec on and replace any damaged wire/connector. If the error s ll occurs,
contact a qualifi ed service technician.
E052
Heat Exchanger Thermistor
Failure
1. Remove the thermistor (do not lose the O-ring) and check for any dirt or debris.
Clean with an Emory cloth. If the thermistor is damaged, replace it.
2. Check the Thermistor sensor wire for a short or disconnec on. Correct any
loose connec on and replace any damaged wire/connector. If the error s ll occurs,
contact a qualifi ed service technician.
E381 Combus on Blockage Press ON/OFF bu on. If error persists, contact a qualifi ed service technician.
E382
Abnormal Propor onal Valve
Current
Press ON/OFF bu on. If error persists, contact a qualifi ed service technician.
60 • Residen al Gas Tankless Water Heater Use and Care Guide
Table 26: Error Code Fault Analysis
Error
Code
Error Descrip on Procedure
E383 Inlet Water Over-temp
1. Verify the inlet water temperature is not above the water heater's set
temperature.
2. Remove the thermistor (do not lose the O-ring) and check for any dirt or debris.
Clean with an Emory cloth. If the thermistor is damaged, replace it.
3. Check the Thermistor sensor wire for a short or disconnec on. Correct any
loose connec on and replace any damaged wire/connector. If the error s ll occurs,
contact a qualifi ed service technician.
E385
Main Gas Solenoid Valve Drive
Circuit Failure
Press ON/OFF bu on. If error persists, contact a qualifi ed service technician.
E388 Bypass Valve Fault
1. Correct any loose connec on and replace any damaged wire/connector.
2. Follow the draining procedure on page 54 to properly drain the water heater.
Remove the bypass valve and inspect for any debris or damage. Replace if needed.
E389 Fan Current AD Failure Press ON/OFF bu on. If error persists, contact a qualifi ed service technician.
E390
Fan Over Max Current without
Speed
Press ON/OFF bu on. If error persists, contact a qualifi ed service technician.
E391
Fan Over Max Current with
Speed
Press ON/OFF bu on. If error persists, contact a qualifi ed service technician.
E392 Fan False Start
Check the fan motor wiring. Correct any loose connec on and replace any damaged
wire/connector. If the error s ll occurs, contact a qualifi ed service technician.
E393 Fan Signal Loss
Check the fan motor wiring. Correct any loose connec on and replace any damaged
wire/connector. If the error s ll occurs, contact a qualifi ed service technician.
E394 Fan Target Speed
1. Check the fan motor wiring. Correct any loose connec on and replace any
damaged wire/connector.
2. With the water heater power disconnected, check the exhaust vent and air intake
piping for any blockages. Remove any blockages. If the error s ll occurs, contact a
qualifi ed service technician.
E395 Fan Current without Drive Press ON/OFF bu on. If error persists, contact a qualifi ed service technician.
E400 Communica on Fault with UIM
Check the UIM wiring. Correct any loose connec on and replace any damaged wire/
connector. If the error s ll occurs, contact a qualifi ed service technician.
TROUBLESHOOTING
Residen al Gas Tankless Water Heater Use and Care Guide • 61
Table 26: Error Code Fault Analysis
Error
Code
Error Descrip on Procedure
E401
Communica on Fault with
Remote Controller
1. Check the Remote Controller wiring. Correct any loose connec ons and replace
any damaged wire/connector.
2. Only one remote controller can be installed, remove any addi onal remote
controllers.
3. If the error s ll occurs, contact a qualifi ed service technician.
E402
Communica on Fault in
Cascade System
1. Check the Cascade wiring. Correct any loose connec ons and replace any
damaged wire/connector.
2. Cycle the heater’s power OFF/ON if the cascade wiring was disconnected while
the system s ll had power.
3. If the error s ll occurs, contact a qualifi ed service technician.
E403
Inconsistent Models in
Cascade-Link
Confi rm all units in Cascade System are the same model. All models in the cascade
system must be the same.
E412
PCB Hardware Fault - Flame
Circuit Failure
Contact a qualifi ed service technician to replace the PCB.
E413 Flame Sensor Fault
1. Check the fl ame sensor wire for a short or disconnec on. Correct any loose
connec on and replace any damaged wire/connector.
2. With the water heater power disconnected, check the exhaust vent and air intake
piping for any blockages. Remove any blockages.
3. Verify the water heater has suffi cient combus on air. Reference the Combus on
and Ven ng Installa on sec on of the manual.
4. Check the installa on area for corrosive elements. Reference the Installa on
Environment sec on in the manual.
5. If the error s ll occurs, contact a qualifi ed service technician.
E414 PCB - Flame Sensor Circuit
1. Check the fl ame sensor wire for a short or disconnec on. Correct any loose
connec on and replace any damaged wire/connector.
2. If the error s ll occurs, contact a qualifi ed service technician to replace the PCB.
E416 Analog/Digital (AD) Value Fault
1. Check the outlet thermistor sensor wire for a short or disconnec on. Correct any
loose connec ons and replace any damaged wire/connector. If the error s ll occurs,
contact a qualifi ed service technician.
2. Remove the outlet thermistor (do not lose the O-ring) and check for any dirt or
debris. Clean with an Emery cloth. If the thermistor is damaged, replace it.
3. If the error s ll occurs, contact a qualifi ed service technician to replace the PCB.
TROUBLESHOOTING
62 • Residen al Gas Tankless Water Heater Use and Care Guide
Table 26: Error Code Fault Analysis
Error
Code
Error Descrip on Procedure
E418 Exhaust High Temperature
1. With the water heater power disconnected, check the exhaust vent and air intake
piping for any blockages. Remove any blockages.
2. Remove the thermistor (do not lose the O-ring) and check for any dirt or debris
clean with Emory cloth. If the thermistor is damaged, replace it.
3. If the error s ll occurs, contact a qualifi ed service technician.
E419 Flame Signal Lost
1. Cycle the heater’s power OFF/ON.
2. If the error s ll occurs, contact a qualifi ed service technician.
E426 Condensate Drain Overfl ow
1. Place a bucket under the water heater to catch any water.
2. With the water heater off , check the condensate drain for any blockages. Remove
any blockages.
3. Check the condensate drain wires for a short or disconnec on. Correct any loose
connec on and replace any damaged wire/connector.
4. Verify the condensate drain line is installed correctly (reference page 40).
E427 Flow Control Valve
1. Check the fl ow control valve wires for a short or disconnec on. Correct any loose
connec ons and replace any damaged wire/connector.
2. Remove the fl ow control valve and inspect for any debris or damage. Replace if
needed. First follow the draining procedure in the Unit Draining & Power Outage
sec on in this manual.
E428 Flow Sensor - Cascade Only
1. Verify the water heater’s opera on is enabled. The heater’s UIM will display the
set temperature when enabled. If it is disabled, press the heater’s ON/OFF bu on
to enable the heater’s opera on.
2. Verify that the heater’s water shutoff valves are open.
3. Check the fl ow sensor wires for a short or disconnec on. Correct any loose
connec ons and replace any damaged wire/connector.
4. Drain the water heater following Unit Draining & Power Outage sec on in this
manual.
5. Remove the fl ow sensor and inspect for any debris or damage. Replace if needed.
6. Remove and clean the inlet water fi lter.
TROUBLESHOOTING
Residen al Gas Tankless Water Heater Use and Care Guide • 63
Table 26: Error Code Fault Analysis
Error
Code
Error Descrip on Procedure
E429
Flow Control Valve Fault -
Cascade Only
1. Check the fl ow control valve wires for a short or disconnec on. Correct any loose
connec ons and replace any damaged wire/connector.
2. Remove the fl ow control valve and inspect for any debris or damage. Replace if
needed. First follow the draining procedure in the Unit Draining & Power Outage
sec on in this manual.
TROUBLESHOOTING
64 • Residen al Gas Tankless Water Heater Use and Care Guide
1
2
3
4
5
6
7
8
COMPONENT LIST
Residen al Gas Tankless Water Heater Use and Care Guide • 65
9
19
20
21
22
23
24
25
26
27
17
18
10
11
12
13
15
16
14
COMPONENT LIST
66 • Residen al Gas Tankless Water Heater Use and Care Guide
When ordering repair parts, always give the following informa on:
1. Model, serial, and product number. This info should be on the le side of the water heater.
2. Item number.
3. Parts descrip on.
Table 27: Repair Parts List
Item
No.
Component List
1 Condensate Tubing (right view)
2 Bypass Water Valve
3 Blower
4 Condensate Trap
5 Main Water Valve
6 Condensate Drain Connec on
7 Hi-Limit Switch
8 Printed Circuit Board
9 Intake Connec on
10 Water Tube Retainer Clip
11 Primary Heat Exchanger
12 Freeze Protec on
13 Manifold Cover
14 Display/Controller
15 Hot Water Outlet
16 Cold Water Inlet
17 Exhaust Connec on
18 Secondary Heat Exchanger
19 Flame Sensor
20 Igniter
21 Burner
22 Manifold
23 Igniter Relay
24 Gas Valve
25 Cartridge Manifold (X3® or Bypass)
26 3/4" Gas Connec on
27 X3® Cartridge/Bypass Cartridge (X3® shown)
COMPONENT LIST
Residen al Gas Tankless Water Heater Use and Care Guide • 67
Flow Rate Capacity Chart
The chart is based on a properly sized gas line and installa on at 0-2,000 . (0-610 m). The water heater will de-rate
approximately 3% (NG) per 1,000 . (305 m) of eleva on increase above 2,000 . (610 m).
0
1
2
3
4
5
6
7
8
9
10
11
12
30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
Flow Rate (GPM)
Temperature Rise (°F)
TM Flow Rate Capacity Chart
TM-160 TM-180 TM-199
APPENDIX
Copyright © 2025, A.O. Smith.
All Rights Reserved
