Installaon Instrucons and
Use & Care Guide
Standard Condensing
Residenal Gas
Tankless Water Heater
Residenal On-Demand Gas Tankless Water Heater
(X3® TECHNOLOGY available on some models)
100402901_2000856682February 2026
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 one gas type only. Make sure you have the
correct gas type before installing this water heater. If you
have diculty following the direcons, 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 installaon, operaons, troubleshoong,
or maintenance. Before you call, write down the model and serial
number from the water heater’s rang plate.
• Incorrect installaon, operaon, or service can damage the water
heater, your house and other property, and present risks including re,
scalding, electric shock, and explosion, causing serious injury or death.
Do not store or use gasoline or other ammable vapors
and liquids in the vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any
phone in your building.
• Immediately call your gas supplier from a neighbor’s
phone. Follow the gas supplier’s instrucons.
• If you cannot reach your gas supplier, call the re de-
partment.
Installaon and service must be performed by a qualied
installer, service agency or the gas supplier.
WARNING: If the informaon in these instrucons
is not followed exactly, a re or explosion may
result causing property damage, personal injury or
death.
LOW LEAD
C
O
NTENT
MODELS:
TM-160M TM-160X3
TM-180M TM-180X3
TM-199M TM-199X3
(M MODELS AVAILABLE IN US ONLY)
2 • Residenal Gas Tankless Water Heater Use and Care Guide
TABLE OF CONTENTS
WATER HEATER BASICS ................................................................................................... 4
Component Overview ................................................................................................................................................................ 4
Typical Installaon (X3® Model Shown) ..................................................................................................................................... 5
Dimensions ................................................................................................................................................................................ 6
Supply Connecons .................................................................................................................................................................... 7
Product Specicaon and Technical Data .................................................................................................................................. 8
IMPORTANT SAFETY INFORMATION ............................................................................... 9
RISKS DURING INSTALLATION AND MAINTENANCE ................................................................................................................. 10
RISKS DURING OPERATION ...................................................................................................................................................... 10
GETTING STARTED ........................................................................................................ 12
Read Before Installaon .......................................................................................................................................................... 12
Included Items ......................................................................................................................................................................... 14
Available Accessories ............................................................................................................................................................... 15
Recommended Tools and Materials ......................................................................................................................................... 16
Recommended Accessories ...................................................................................................................................................... 16
INSTALLATION .............................................................................................................. 17
Installaon Environment ......................................................................................................................................................... 17
Unit Clearances........................................................................................................................................................................ 17
Mounng the Water Heater .................................................................................................................................................... 17
Combuson and Venng Installaon ....................................................................................................................................... 18
Combuson Air Supply Opons ............................................................................................................................................... 20
Venng .................................................................................................................................................................................... 21
Installing the Vent Pipe ............................................................................................................................................................ 23
Exhaust Vent for Indoor Installaon ........................................................................................................................................ 24
Input Rate at Maximum Vent Length ...................................................................................................................................... 24
Typical PDV Conguraons:..................................................................................................................................................... 25
Typical PV Conguraons: ....................................................................................................................................................... 25
Vent Terminaons .................................................................................................................................................................... 26
Clearances for Sidewall Terminaons ...................................................................................................................................... 29
Clearances for Rooop Terminaons ....................................................................................................................................... 31
Exhaust Vent for Outdoor Installaon ..................................................................................................................................... 34
Gas Supply and Gas Pipe Sizing ............................................................................................................................................... 35
Water Connecons .................................................................................................................................................................. 37
X3® Technology ........................................................................................................................................................................ 38
Residenal Gas Tankless Water Heater Use and Care Guide • 3
TABLE OF CONTENTS
Pressure Relief Valve ................................................................................................................................................................ 39
Condensate Drain .................................................................................................................................................................... 39
Recirculaon ............................................................................................................................................................................ 40
Electrical Connecons .............................................................................................................................................................. 42
Accessory Connecons............................................................................................................................................................. 42
Cascade System ....................................................................................................................................................................... 44
OPERATION .................................................................................................................. 46
FOR YOUR SAFETY, READ BEFORE OPERATING ........................................................................................................................ 46
Start-Up Instrucons ................................................................................................................................................................ 46
Shut-Down Instrucons ........................................................................................................................................................... 46
Emergency Shut-Down ............................................................................................................................................................ 46
User Interface Module (UIM) & Remote Controller Display Overview ..................................................................................... 48
Temperature Sengs............................................................................................................................................................... 49
Conguraon Mode (C Mode) ................................................................................................................................................. 50
Cascade Conguraon............................................................................................................................................................. 54
Unit Conversion Mode ............................................................................................................................................................. 54
MAINTENANCE ............................................................................................................ 55
Regular Maintenance .............................................................................................................................................................. 55
Freeze Protecon System ......................................................................................................................................................... 55
Unit Draining & Power Outage (Freeze Protecon) ................................................................................................................. 56
Discharge Condensate ............................................................................................................................................................. 56
Inlet Water Filter ...................................................................................................................................................................... 56
TROUBLESHOOTING ..................................................................................................... 57
General Troubleshoong ......................................................................................................................................................... 57
Error Codes .............................................................................................................................................................................. 59
Fault Analysis of Error Codes ................................................................................................................................................... 60
COMPONENT LIST ........................................................................................................ 66
Internal Component View (A) .................................................................................................................................................. 66
Internal Component View (B) .................................................................................................................................................. 67
External Component View ....................................................................................................................................................... 68
Internal / External Component List .......................................................................................................................................... 69
APPENDIX .................................................................................................................... 70
Electrical Wiring Diagram ........................................................................................................................................................ 70
Flow Rate Capacity Chart ........................................................................................................................................................ 71
4 • Residenal Gas Tankless Water Heater Use and Care Guide
WATER HEATER BASICS
Component Overview
(TM-160X3, TM-180X3, TM-199X3 Models 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 Prevenon Technology to inhibit scale formaon within the heat exchanger tubing of this unit.
Part of the X3® Technology’s an-scale protecon 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 operaon of the unit. X3® Scale Prevenon Technology reduces the formaon
of scale in the heat exchanger, extending the operang life of the unit in typical potable water installaons. Specic water condions may
impact the eciency 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 eecveness 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 eld supplied with this model.
Residenal Gas Tankless Water Heater Use and Care Guide • 5
WATER HEATER BASICS
Typical Installaon (X3® Model Shown)
Water
Shut-off Valve
Expansion
Tank
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 • Residenal 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
Residenal Gas Tankless Water Heater Use and Care Guide • 7
WATER HEATER BASICS
Supply Connecons
2
1
4
5
WALL
HOT
COLD
GAS
3
Table 1: Supply Connecons
Item Descripon Dimensions Connecon 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 Connecon 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 • Residenal Gas Tankless Water Heater Use and Care Guide
WATER HEATER BASICS
Product Specicaon and Technical Data
X3® Models: Comes with the X3® Scale Prevenon Technology cartridge and pressure relief valve installed.
M Models (Available in US Only): Comes with the Bypass cartridge installed.
Table 2: Specicaons
Model TM-160 TM-180 TM-199
Minimum Input
(Natural Gas & Propane)
BTU/H 10,000
Maximum Input
(Natural Gas & Propane)
BTU/H 160,000 180,000 199,000
Gas Connecon 3/4" NPT
Water Connecons 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), Acvaon Min: 0.4 (1.5)
Natural Gas
Inlet Pressure
inch W.C. (kPa)
Min: 4.0 (1.0)
Max: 10.5 (2.62)
Propane Gas
Inlet Pressure
inch W.C. (kPa)
Min: 8.0 (2.0)
Max: 14.0 (3.49)
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
Ignion Electronic Ignion
Electric Supply 120 V, 60 Hz, <5 A
Water Heater Category*** Category IV
*40 psi or above is recommended for maximum ow.
**Minimum acvaon ow rate may increase if energy demand required is below the minimum input rang of the water heater.
***Water Heater Category - does not apply to Outdoor or Direct Vent installaons.
Category IV - a water heater that operates with a posive vent stac pressure and with a vent gas temperature that may cause
excessive condensate producon in the vent.
NOTES:
• Check the rang plate to ensure that this product matches your specicaons.
• The manufacturer reserves the right to disconnue, or change at any me, specicaons or designs without noce and with-
out incurring obligaon.
Residenal Gas Tankless Water Heater Use and Care Guide • 9
IMPORTANT SAFETY INFORMATION
Read and follow all safety messages and instrucons in this
manual.
This is the safety alert symbol. It is used to alert you to
potenal 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
instrucons, labels, or the rang 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 informaon in these instrucons is not followed
exactly, a re or explosion may result causing property damage, personal
injury or death. Do not store or use gasoline or other ammable vapors and
liquids in the vicinity of this or any other appliance.
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 indicaon of leaking gas. We recommend installing a fuel
gas and carbon monoxide detector.
This product is cered to comply with a maximum weighted average of
0.25% lead content as required in some areas.
DANGER indicates a hazardous
situaon that, if not avoided, will
result in death or serious injury.
WARNING indicates a hazardous
situaon that, if not avoided, could
result in death or serious injury.
CAUTION indicates a hazardous
situaon that, if not avoided, could
result in minor or moderate injury.
NOTICE indicates pracces 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 informaon to keep
Fill out this secon and keep this manual
in the pocket of the water heater for
reference.
Date Purchased:
Model Number:
Serial number:
Maintenance performed:* Date:
10 • Residenal Gas Tankless Water Heater Use and Care Guide
To reduce the risk of property
damage, serious injury or death, read
and follow the precauons below,
all labels on the water heater, and
the safety messages and instrucons
throughout this manual.
RISKS DURING
INSTALLATION AND
MAINTENANCE
Liing Risk
WARNING! The
water heater is
heavy. Follow these
precauons to reduce the risk of
property damage, injuries from liing
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 liing.
• Use an appliance dolly or hand truck
to move the water heater.
Explosion Risk
WARNING! This water
heater is designed for
Natural Gas operaon only. Refer
to the water heater’s rang plate.
Failure to follow these instrucons
can result in serious injury or death
from explosion, re or carbon
monoxide poisoning.
• DO NOT connect a Natural Gas wa-
ter heater to an L.P. Gas supply.
• DO NOT connect an L.P. Gas water
heater to a Natural Gas supply.
• Use a new gas supply line approved
for the water heater gas type that
meets local and state/provincial
codes.
• Install a full port shut-o valve on
the gas supply line.
• Maintain the Pressure Relief Valve
properly. Follow the maintenance
instrucons provided by the manu-
facturer of the Pressure Relief Valve
(label aached to Pressure Relief
Valve). If no label is aached to the
Pressure Relief Valve, follow the
instrucons in the Pressure Relief
Valve Maintenance secon 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 gas supply
pressure must not exceed the
maximum supply pressure as stated
on the water heater’s rang plate.
Have a qualied 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 rang plate can
result in serious injury or death from
explosion or re.
RISKS DURING
OPERATION
Scalding Risk
This water heater
can make water hot
enough to cause
severe burns instantly, resulng in
severe injury or death.
• Feel water before bathing or show-
ering.
• To reduce the risk of scalding, install
Thermostac Mixing Valves (tem-
perature liming 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 instrucons 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 seng,
Thermostac Mixing Valves located
at each point-of-use are parcularly
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 informaon about changing
the factory temperature seng, refer
to the “Temperature Sengs” secon
in this manual on page 49.
• Water temperature will be hoer if
someone adjusted the set tempera-
ture to a higher seng.
• Should overheang occur or the
burner fail to shut o, turn o the
manual gas supply valve to the
water heater and call a qualied
person.
IMPORTANT SAFETY INFORMATION
Residenal Gas Tankless Water Heater Use and Care Guide • 11
IMPORTANT SAFETY INFORMATION
To reduce the risk of unusually hot
water reaching the xtures in the
house, install Thermostac Mixing
Valves at each point-of-use.
If anyone in your home is at parcular
risk of scalding (for example, the
elderly, children, or people with
disabilies) or if there is a local code
or state/provincial law requiring a
certain water temperature at the
hot water tap, these precauons are
parcularly important.
According to a naonal 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 Contaminaon 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 heang only.
Fire Risk
To reduce the risk of a
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
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
qualied installer or service agency
to replace a ooded water heater.
Do not aempt to repair the unit. It
must be replaced.
Explosion Risk
High pressures in the
water heater can cause
an explosion resulng 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 eld
supplied for M models. Addional
pressure protecve equipment may
be required by local codes.
A naonally recognized tesng
laboratory maintains public inspecon
of the valve producon process
and ceres 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 rang of the water heater as
stated on the rang 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, resulng in
serious injury or death. This water
heater must be supplied with
adequate combuson air and must
be properly vented to the outdoors.
Have a qualied person (licensed
plumber, authorized gas company
personnel, or authorized service
technician) install the venng system
using these installaon instrucons.
Install a fuel gas and carbon
monoxide detector in the living areas
of your home.
Failure to follow these instrucons
can result in serious injury or death
from carbon monoxide poisoning.
12 • Residenal Gas Tankless Water Heater Use and Care Guide
Read Before
Installaon
1
Review all of the instrucons
before you begin work.
Improper installaon 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, posive
vented stac pressure water
heater (vent gas temperatures may
cause excessive condensate
producon in the vent), which takes
its combuson air either from the
installaon 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 edion of ANSI Z223.1/NFPA
54, Naonal Fuel Gas Code in the
USA or B149.1, Natural Gas and Pro-
pane Installaon Code in Canada.
• For installaon in manufactured
homes (mobile homes) follow the
current edion of The Manufactured
Home Construcon 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
jurisdicon. In the absence of such
requirements, follow the current
edion of the Naonal Electrical
Code ANSI/NFPA 70 in the USA or
the current edion 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
Naonal Fire Protecon Associaon
1 Baerymarch Park
Quincy, MA 02269
Check with local code ocials about
codes governing this installaon.
Have your installaon inspected by a
code ocial to ensure the installaon
meets all local codes.
NOTICE: Installaon and service must
be performed by a qualied installer
(for example, a licensed plumber or
gas er). Otherwise, the warranty
will not apply. The installer (licensed
professional) is responsible for the
correct installaon of the water
heater and for compliance with all
naonal, state/provincial, and local
codes.
Massachuses code requires this
water heater to be installed in
accordance with Massachuses
248-CMR 2.00 and 248-CMR 5.00:
State Plumbing Code. Other local
and state authories may have
similar requirements or other codes
applicable to the installaon of this
water heater.
3
Before you start, be sure to
check the following:
WARNING! Do not store or use
ammable materials, vapors, or
liquids in the same locaon where
this water heater is installed.
• All gas water heaters require correct
installaon to ensure safe and e-
cient operaon. This manual must
be followed exactly. Read the enre
manual before installaon and re-
view the "Important Safety Informa-
on" secon (see page 9).
• Carefully plan the installaon loca-
on of the heater and vent termina-
ons.
• The water heater must be installed
where the proper amount of
combuson air will be available to
it at all mes without obstrucons.
When installed indoors, the water
heater can be direct vented.
• The length of piping between the
water heater and xture determines
the me it takes for the hot water
to arrive. Consider installing the
water heater closer to xtures if
the plumbing system allows for it.
The water heater should be the rst
appliance to access the water line
aer the ulity water meter.
• Locate your water heater close to a
drain where water leakage will not
do damage to surrounding areas. As
with any water heang appliance,
the potenal for leakage at some
me in the life of the product does
exist. A drain pan, or other means of
protecon 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 addion, you
may install an acve water leak
detector with a shuto valve which
can turn o 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" secon for
proper clearances (see page 17).
NOTICE: For outdoor installaons,
locate the water heater in an open,
unroofed 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 ac due to safety issues. See
the installaon secon for further
informaon.
• Failure to observe these warnings
could result in severe personal inju-
ry, death, and/or property damage.
GETTING STARTED
Residenal Gas Tankless Water Heater Use and Care Guide • 13
GETTING STARTED
Venng/Combuson
• DO NOT install the water heater
where water, debris or ammable
vapors may get into the 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 locaon where gas and water can
accumulate.
• DO NOT install the unit where the
exhaust vent is poinng into any
opening in a building or where the
noise may disturb your neighbors.
Make sure the vent terminaon
meets the required clearance from
any doorway or opening to prevent
exhaust from entering a building.
Check local code requirements prior
to installaon.
• DO NOT install the exhaust vent or
outdoor model vent terminal within
3 feet (914 mm) of a venlated or
unvenlated sot or eave vent; or
to a deck or porch. Vent termina-
ons must be at least 2 (610 mm)
away from an inside corner for both
direct vent or other than direct vent
installaons (Figure 1).
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.
USA: 1 (30 cm) min.
Canada: 3 (91 cm) min.
USA: 1 (30 cm) min.
Canada: 3 (91 cm) min.
USA: 12 in. (30 cm) above grade and
above ancipated snow level
Canada: 12 in. (30 cm) above grade
USA: 1 (30 cm) min.
Canada: 3 (91 cm) min.
Ancipated snow level
Figure 2 - Minimum Vent Clearance (Indoor Direct Venng)
4 (122 cm) min.
4 (122 cm) min.4 (122 cm) min.
Figure 3 - Minimum Vent Clearances (Outdoor Other than Direct Venng)
14 • Residenal Gas Tankless Water Heater Use and Care Guide
Included Items
Table 4: Items Included with your Water Heater
Item Product Image Descripon
Conguraon
X3 M
Manual
Installaon Instrucons and Use & Care Guide for
TM-160, TM-180 & TM-199 series 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 Mounng
Bracket
Kit for mounng water heater contains:
• Mounng 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 conguraon water heaters without X3® scale
reducon 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 connecng tankless
water heaters in series for greater output:
• P/N 100371915
√ √
GETTING STARTED
Residenal Gas Tankless Water Heater Use and Care Guide • 15
GETTING STARTED
Available Accessories
Table 5: Accessories Available for your Water Heater
Item Product Image Descripon
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 connecng tankless water heaters to the
internet and adapter to connect to the water heater:
• P/N 100371922
Remote
Controller
Remote Controller with 10 . (3m) cable:
• P/N 100383909
Communicaon
Cables
Communicaon Cable Extensions for Remote Controller, Wi-Fi Module, or
On-Demand Receiver:
• P/N 100377341 for 10 . (3 m)
• P/N 100377342 for 32 . (10 m)
Cartridge Freeze
Protecon
Cartridge Freeze Protecon can add an extra layer of freeze protecon to
external cartridge:
• P/N 100325654 for X3® models
• P/N 100371918 for M models
Pipe Cover
Pipe Cover protects plumbing connecons to the heater while improving
the appearance of the installaon. Axes to boom 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 • Residenal Gas Tankless Water Heater Use and Care Guide
Table 5: Accessories Available for your Water Heater
Item Product Image Descripon
Outdoor Vent
Cap Kit
Outdoor Installaon kit containing the Outdoor Vent Cap and User
Interface Cover:
• P/N 100369060
Isolaon Valve
Kit with Pressure
Relief Valve
Isolaon Valve supports roune maintenance and allows for draining
and 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
specic type of plasc pipe used:
CPVC or PEX (cross-linked polyeth-
ylene). Do not use PVC pipe.
• Non-corrosive gas leak detecon
soluon 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
detecon device.
• An appliance dolly or hand truck to
move the water heater.
Recommended
Accessories
• Automac water leak detecon and
shut-o device
• Thermostac Mixing Valves at each
point-of-use
• Fuel gas and carbon monoxide
detector
Residenal Gas Tankless Water Heater Use and Care Guide • 17
INSTALLATION
Installaon Environment
Proper Mounng and
Clearance
The water heater shall be securely
mounted on a wall that can support
the weight of the water heater. A wall
mounng 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 eld
supplied pipe hangers. The water
heater shall not bear the weight of
these lines. The water heater requires
proper installaon clearance for
operaon and service as described in
"Unit Clearances" on the right.
WARNING! The installer (licensed
professional) is responsible for the
correct installaon of the water
heater and for compliance with all
naonal, 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 beer protecon
from the elements. The warranty will
not be covered if the water heater is
damaged due to freezing. See "Freeze
Protecon System" on page 55.
Combuson Air Supply
The water heater requires fresh
combuson air and should be
free of corrosive elements and
ammable vapors. If it is installed in a
contaminated or conned area, direct
venng installaon is recommended.
Proper Venlaon
For proper operaon the water heater
must be vented in accordance with
the secon "Venng" of the current
edion of the ANSI Z223.1/NFPA 54,
Naonal Fuel Gas Code in the United
States and/or Secon 8 of the B149.1,
Natural Gas and Propane Installaon
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 pracces.
Unit Clearances
WARNING! Maintain all clearances
around the water heater. Failure
to do so could create a re hazard,
potenally 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)
Soffit / 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.
Mounng the Water
Heater
1
Secure the wall mounng
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 mounng
on any other surface, use fasteners
approved for that wall material/
construcon. 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 Installaon
2
Hang the heater on the
mounng bracket (Figure 6).
Figure 6 - Use Mounng Screws to Secure Water
Heater to Bracket
3
Secure the water heater
rmly, fastening the
appropriate screws for wall
construcon into the upper and
boom brackets of the water heater
and wall. NOTICE: These screws are
not provided.
ON/OFF
DOWN
UP SETTING
Secure with screws.
Figure 7 - Use Mounng Screws to Secure Water
Heater to Bracket
18 • Residenal Gas Tankless Water Heater Use and Care Guide
Combuson and
Venng Installaon
Combuson 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 combuson and venlaon. This
secon does not apply if the water
heater is direct vented. Consult a
qualied 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 combuson and
venlaon. Without sucient air,
your water heater will have frequent
outages and may emit excessive
and abnormal amounts of carbon
monoxide.
Before beginning:
Calculate total BTU/hr rang of all
appliances.
To calculate the combuson air and
venlaon required, add up the total
BTU/hr rangs of all gas burning
appliances (e.g., water heaters,
furnaces, clothes dryers) in the same
area.
Your water heater’s BTU/hr rang is
on the rang plate, located on the
side of the water heater. The BTU/
hr rangs should be on the other
appliances’ rang plates. If you have
trouble determining the BTU/hr
rangs, contact the manufacturer or
have a qualied person determine the
venlaon requirements.
NOTICE: If you are replacing your
old water heater with one that has a
higher BTU/hr rang, the amount of
venlaon required may be greater.
Example:
Gas Burning Appliance BTU/hr Rang
Gas Water Heater 199,000
Furnace 75,000
Dryer 20,000
Total 294,000
Your Appliances:
Gas Burning Appliance BTU/hr Rang
Gas Water Heater
Total
Opon A: Installaon without
outside venlaon (not
recommended)
Venlaon with outside air is
recommended for all installaons.
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 oen 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 venlaon. If you are
unsure if your installaon locaon has
enough venlaon, contact your local
gas ulity company or code ocials
for a safety inspecon.
The following instrucons will help
determine if it may be possible to
install without outside venlaon. If
there is not enough venlaon, you
will need to venlate with outside air.
Check for Chemicals:
Installaons where corrosive
chemicals may be present require
outside air. Air for combuson and
venlaon must be clean and free of
corrosive or acid-forming chemicals
such as sulfur, uorine, and chlorine.
Venlaon 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
locaons 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 beer
esmate of the air available.
Room Volume – Object Volume = Air
Volume
A2: Calculate required air
volume
A water heater installed in an
unconned space, such as an ac 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
Residenal 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 sucient air.
Use Opon 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 venlaon.
A3: Check that combuson
venlaon is adequate
Because modern homes are oen
well-sealed to prevent dras, a
large room may not provide enough
combuson air without venlaon.
Conrm that your installaon has
enough combuson air.
Opon B: Installaon with
outside venlaon
Venlaon with outside air is
recommended, and for most
installaons, is needed. There may be
exisng venlaon that is adequate,
or you may need to add more
venlaon.
Supplying outside air typically requires
two openings. One opening must be
within 12 inches from the 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
venlang with air from another room.
B1: Determine type of
venlaon
There are several types of venlaon
that can be used:
1. Direct to outdoors
2. Vercal ducts
3. Horizontal ducts
4. Single opening (not recom-
mended); must be at least 100
square inches. Not appropriate
for conned spaces smaller than
50 cubic feet per 1,000 Btu/hr as
calculated in secon A or when
geng air from another room.
5. From a larger room inside the
house (not recommended —
refer to secon 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 rang of all
appliances in the space (use your
calculaon 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 venlaon.
B3: Calculate minimum size of
vent openings and ducts
The vent cross-seconal 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-seconal area:
Cross-seconal area = minimum free
area required ÷ percent free area of
covering (in decimals – e.g., 60% = .6)
For example, an installaon 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
ow:
• Each vent opening must be no small-
er than 100 square inches.
• Ducts must have the same
cross-seconal 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-
macally during operaon.
• Keep louvers and grilles clean and
free of debris or other obstrucons.
B4: Check that air source is
clean and free of chemicals
Air for combuson and venlaon
must be clean and free of corrosive
or ammable chemicals. A failure due
to corrosive chemicals in the air is not
covered by the warranty. Combuson
air must be free of acid-forming
chemicals such as sulfur, uorine, and
chlorine. Be sure that air at the vent
inlets is free of such chemicals.
B5: Check that combuson
venlaon is adequate
Conrm that your installaon has
enough combuson air.
20 • Residenal Gas Tankless Water Heater Use and Care Guide
Combuson Air Supply Opons
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 - Vercal 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
Minimum Free Area of Permanent Openings for Venlaon and Combuson Air Supply – Air from outdoor or indoor spaces.
Based on the total BTU/hr input rang for all gas burning appliances within a conned space.
Opening Source Minimum Free Area
Direct to Outdoors* 1 in² (6.5 cm²) per 4,000 BTU/hr (see Figure 8 & 9)
Vercal 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 venlated ac, a venlated crawl space, or through an outside wall.
**United States: For direcon on combining spaces in dierent stories within the structure, refer to the current edion of the
Naonal Fuel Gas Code ANSI Z223.1/NFPA 54. In Canada, follow B149.1, Natural Gas and Propane Installaon Code.
INSTALLATION
Residenal Gas Tankless Water Heater Use and Care Guide • 21
INSTALLATION
Venng
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 qualied
person. Examples of a qualied
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 edion
of ANSI Z223.1/NFPA 54, Naonal
Fuel Gas Code in the USA or B149.1,
Natural Gas and Propane Installaon
Code in Canada, as well as applicable
local building codes.
The use of venng materials approved
for Category III/IV appliances is
recommended whenever possible.
However, the Indoor model may also
be vented with plasc pipe materials
such as ABS, PVC (solid core), CPVC
(solid core), or polypropylene. For
details, please refer to the "Exhaust
Vent for Indoor Installaon" secon
on page 24. Vent installaons in
Canada which ulize plasc vent
systems must use venng that
complies with ULC S636.
Venng may not intermingle with
other manufactured material types,
other than approved adapters.
General Rules for Venng
Water Heaters:
• Follow the vent pipe's manufactur-
er's instrucons when installing the
vent pipe.
• Place the water heater as close as
possible to the vent terminaon.
• 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 inspecon 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
venng systems is prohibited.
• Covering non-metallic vent pipe and
ngs with thermal insulaon is
prohibited.
• Sidewall venng is recommended
for the Indoor model. Vercal vent-
ing (roof terminaon) is acceptable.
• The manufacturer recommends run-
ning the exhaust vent and the intake
pipe as parallel as possible.
• For rooop venng, a rain cap or
other form of terminaon 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 ue serving
a separate appliance, designed to
burn solid fuel.
General Rules for Vent
Terminaons:
• Avoid locang the water heater
vent terminaon near any air intake
devices. These fans can pick up
the exhaust ue products from the
water heater and return them to the
building. This can create a health
hazard.
• Locate the vent terminaon so that
it cannot be blocked by any debris,
at any me. Most codes require that
the terminaon be at least 12 inches
(305 mm) above grade and anci-
pated snow level, but the installer
may determine if it should be higher
depending on the job site condion
and applicable codes.
• A proper sidewall terminaon is rec-
ommended when the water heater
is vented through a sidewall.
• Check the clearances from the
exhaust terminaon 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
instrucons and local codes.
Replacing a Water Heater
Using the Exisng Vent System
WARNING! Improper venng of
this appliance can result in excessive
levels of carbon monoxide which
can result in severe personal injury
or death. Improper installaon
can cause nausea or asphyxiaon,
severe injury or death from carbon
monoxide and ue gases poisoning.
The product warranty will not apply
to improper installaons.
DO NOT use Category I or Category II
venng system with this water heater.
If exisng venng and vent
terminaons are used, they MUST be
cleared of ALL restricons, such as a
restrictor plate, for proper operaon.
Read the “Installing Vent Pipe”
secon on page 23 of this manual
and make sure your vent system
is properly installed. Inspect the
exisng vent system for obstrucons,
corrosion, and proper installaon.
Repair or replace if necessary.
22 • Residenal Gas Tankless Water Heater Use and Care Guide
Table 7: Acceptable Plasc Vent Pipe Table
Item Material United States Canada
Exhaust Pipe and
Fings
Schedule 40 PVC ANSI/ASTM D1785
ULC S636 Cered
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 Cered
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 venng systems is
prohibited. Covering non-metallic vent pipe and ngs with thermal insulaon 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 Vercal or Horizontal Vent Length
0 to 7,800 . (0 to 2,377 m)
2 Inch Venng (50 . / 15.3 m) 3 Inch Venng (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 connecon, 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 congure the water heater aer installaon. See "Conguraon Mode (C Mode)" starng on
page 50.
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 Venng
3" Pipe
2" to 3"
Adapter
2" Pipe
2" Pipe
Figure 16 - Direct Vent Installaon
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 Installaon
Residenal Gas Tankless Water Heater Use and Care Guide • 23
INSTALLATION
Installing the Vent Pipe
WARNING! Improper installaon
can cause nausea or asphyxiaon,
severe injury or death from carbon
monoxide and ue gases poisoning.
The product warranty will not apply
to improper installaons.
• When inserng 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 connecon rmly.
• Improper venng 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
unl 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.
For 3 inch piping:
Install a 2 inch x 3 inch increaser to
convert to 3 inch venng. A 12 inch
(305 mm) maximum length straight
pipe may be used to t a 2 inch x 3
inch increaser (Figure 16 & Figure 17).
WARNING! The exhaust vent pipe
connecon to the water heater must
be ush to maintain a proper seal.
Check pipe for a 90° edge before
installaon. DO NOT use a eld cut
end for the connecon. Failure to
follow these instrucons can cause
carbon monoxide poisoning or death.
2
Use a Phillips screwdriver to
ghten the clamps (Figure
15).
3
Use the specied self-tapping
screws to secure the venng
to the intake and exhaust
ports (Figure 15).
Exhaust Vent for Indoor
Installaon
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, plasc venng must be
cered to ULC S636 standards.
• The maximum length of the exhaust
venng 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 venng secons
1/4 inch (6 mm) upwards for every
12 inches (305 mm) toward the
terminaon or according to local
or state/provincial codes, or in the
absence of local or state/provincial
codes, the current edion of ANSI
Z223.1/NFPA 54, Naonal Fuel Gas
Code in the USA or B149.1, Natural
Gas and Propane Installaon 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 venlaon 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 Maximum
Vent Length
Model Vent Size
Derate at Max.
Vent Length
TM-160
2 Inch 24%
3 Inch 14%
TM-180
2 Inch 30%
3 Inch 18%
TM-199
2 Inch 35%
3 Inch 23%
24 • Residenal Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Typical PDV Conguraons:
Figure 19 & Figure 20 illustrate typical venng conguraon
examples for Power Direct Vent (PDV) applicaons.
Hanger
Figure 19 - Power Direct Vent Horizontal Installaon
Fire Stop
Roof
Figure 20 - Power Direct Vent Vercal Installaon
Typical PV Conguraons:
Figure 21 & Figure 22 illustrate typical venng conguraon
examples for Power Vent (PV) applicaons.
Hanger
Figure 21 - Power Vent Horizontal Installaon
Roof
Flashing
Fire
Stop
Figure 22 - Power Vent Vercal Installaon
Residenal Gas Tankless Water Heater Use and Care Guide • 25
INSTALLATION
26 • Residenal Gas Tankless Water Heater Use and Care Guide
Vent Terminaons
Table 10: PVC Vent Terminaons and Venng Components
PVC LOW PROFILE TERMINATION
If terminaon is used in vercal posion, 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 Prole 100187903 196984 397984 1 .
3" Low Prole 100187887 196985 397985 1 .
PVC CONCENTRIC TERMINATION
B
A
C
A B C
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 .
PVC RADIUS ELBOWS
Vent Pipe Size & Elbow Type *Equivalent Length
2" 45° Elbow / 3" 45° Elbow 1 .
2" 90° Elbow / 3" 90° Elbow 3 .
Table 11: Polypropylene Vent Terminaons and Venng Components
POLYPROPYLENE CONCENTRIC TERMINATION
Vent Pipe Size Centrotherm Part Number *Equivalent Length
2" Low Prole Terminaon ISLPT0202 6 . (160k/180k/199k)
3" Low Prole Terminaon ISLPT0303 5 . (160k/180k/199k)
INSTALLATION
NOTICE: Equivalent lengths for Polypropylene
Concentric Terminaons change based on model.
See the columns below to determine correct
equivalent lengths for your applicaon.
Residenal Gas Tankless Water Heater Use and Care Guide • 27
Table 11: Polypropylene Vent Terminaons and Venng 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 venng or 150 . (45.7 m) for 3 inch venng. Each elbow added is the
equivalent length of 3 . for both 2 inch and 3 inch venng. Make note of total vent length for your applicaon, including vent
terminaon. See "Conguraon Mode (C Mode)" starng on page 50.
INSTALLATION
28 • Residenal Gas Tankless Water Heater Use and Care Guide
Vent Terminaon 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
is not permied
Regulator/Gas meter
vent outlet
I
Table 12: Vent Terminaon Clearances
Canada Installaons
1
US Installaons
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
Vercal clearance to venlated sot 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 unvenlated sot 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 vercal
center line of the regulator vent
outlet to a maximum vercal
distance of 15 (4.5 m)
* *
J
Clearance to non-mechanical air supply inlet to a
building or the combuson 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 installaon codes and the requirements of the gas supplier.
**A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and serves both dwellings.
***Permied only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the oor.
The vent for condensing water heaters shall not terminate:
• over public walkways; or
• near sot 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 operaon of regulators, relief valves, or other equipment.
Notes:
1) In accordance with the current CSA B149.1, Natural Gas and Propane Installaon Code.
2) In accordance with the current ANSI Z223.1/NFPA 54, Naonal Fuel Gas Code.
INSTALLATION
Residenal Gas Tankless Water Heater Use and Care Guide • 29
INSTALLATION
Clearances for Sidewall
Terminaons
WARNING! Improper installaon
can result in carbon monoxide
poisoning or death. Follow all local
and naonal codes regarding proper
terminaon clearances. In the
absence of such codes, the clearances
below can be used as guidelines.
Local codes supersede these
guidelines.
Mulple Sidewall Terminaons
An exhaust terminaon must be at
least 1 . (305 mm) from another
exhaust terminaon and 2 . (610
mm) form an inside corner (Figure
23).
Exhaust terminaons should be at
least 2 . (610 mm) away from an
opposite surface/wall. Do not place
the terminaon directly in front of an
opening into a building (Figure 24).
Mulple Direct Vent Sidewall
Terminaons
A direct vent (DV) terminaon must
be at least 1 . (305 mm) from
another DV terminaon and 2 .
(610 mm) from an inside corner
(Figure 25).
DV sidewall terminaons should be
at least 2 . (610 mm) away from an
opposite surface/wall. Do not place
the terminaon directly in front of an
opening into a building (Figure 26).
Anticipated Snow Level
Inside
Corner
Exhaust Terminations
1 ft
(305 mm)
min.
1 ft
(305 mm)
min.
2 ft
(610 mm)
min.
1 ft
(305 mm)
min.
Figure 23 - Mulple Sidewall Terminaons
Exhaust
Termination
2 ft
(610 mm)
min.
Figure 24 - Sidewall Terminaon Minimum Distance to 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 - Mulple DV Sidewall Terminaons
Exhaust
Termination
2 ft
(610 mm)
min.
Figure 26 - DV Sidewall Terminaon Minimum Distance to Wall
30 • Residenal Gas Tankless Water Heater Use and Care Guide
Power Direct Vent (PDV) Sidewall Terminaons with Separate Penetraons
For PDV terminaons that use two separate penetraons for the intake and exhaust, keep the terminaon clearances as shown
in Figure 27 & Figure 28 below.
INSTALLATION
0.5 ft.
(159 mm)
min.
0.5 ft.
(159 mm)
min.
1 ft.
(305 mm)
min.
Exterior InteriorSideview
Figure 27 - Separate Sidewall Penetraon Example A
0.5 ft.
(159 mm)
min.
0.5 ft.
(159 mm)
min.
1 ft.
(305 mm)
min.
Exterior InteriorSideview
Figure 28 - Separate Sidewall Penetraon Example B
Residenal Gas Tankless Water Heater Use and Care Guide • 31
Clearances for Rooop
Terminaons
WARNING! Follow all local and
naonal codes regarding proper
terminaon 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 dier
from the guidelines in this secon. In
Canada, follow the requirements of
the current edion of B149.1, Natural
Gas and Propane Installaon Code
as well as local and provincial codes.
Contact your local code enforcement
agency for direcon.
• Exhaust terminaons must be at
least 1 . (305 mm) away from any
obstrucons.
• Minimum spacing between mulple
intake terminals is 1 . (305 mm).
• Minimum spacing between mulple
exhaust terminals is 1 . (305 mm).
• The exhaust terminaon must be
a horizontal distance of at least 2
. (610 mm) from a wall or surface
unless specied dierently 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
Follow all local and naonal codes regarding proper terminaon clearances. In the absence of such codes, the clearances below
must be met. Local codes supersede these clearances.
Figure 29 - Pitched Roof with Mulple Vent Terminaons
32 • Residenal 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
Follow all local and naonal codes regarding proper terminaon clearances. In the absence of such codes, the clearances below
must be met. Local codes supersede these clearances.
Figure 30 - Pitched Roof with Mulple Vercal Concentric Terminaons
Residenal 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.
Follow all local and naonal codes regarding proper terminaon clearances. In the absence of such codes, the clearances below
must be met. Local codes supersede these clearances.
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 31 - Flat Roof with Mulple Vercal Terminaons
Exhaust Vent for
Outdoor Installaon
There must be at least 3 . (914 mm)
of space between the exhaust vent
and a venlated or unvenlated sot
or eave vent; or to a deck or porch.
See "Unit Clearances" on page 17
for required outdoor clearances.
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 32.
Screws (4x)
Figure 32 - Remove Screws from Top Plate
2
Orient the outdoor vent cap
as shown in Figure 33. Secure
the outdoor vent cap with
the four screws removed in the
previous step.
Figure 33 - 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 condions and
accidental control adjustments (Figure
34).
Figure 34 - Install UIM Overlay
4
Remove the front cover to
the water heater cabinet.
5
Locate the air inlet plate as
shown in Figure 35. 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 35 - Air Inlet Plate Orientaon
6
Install front cover to water
heater.
7
Connect power to the water
heater. See “Electrical
Connecons” 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
Connecons” on page 42.
Outdoor Available
Accessories
It is recommended that a Cartridge
Freeze Protecon Kit be installed if
the water heater is installed outside
or in uncondioned areas subject to
freezing temperatures.
A pipe cover is available and axes
to the boom of the water heater.
It protects plumbing connecons to
the water heater while improving the
appearance of the installaon.
For more informaon see “Available
Accessories” on page 15.
34 • Residenal Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Residenal 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 one gas type only. Refer
to the water heater’s rang plate.
Failure to follow these instrucons
can result in serious injury or death
from explosion, re or carbon
monoxide poisoning.
Ensure that any and all gas regulators
used are operang properly and
providing gas pressures within the
specied 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 edions of ANSI Z223.1/NFPA
54, Naonal Fuel Gas Code in the USA
or B149.1, Natural Gas and Propane
Installaon Code in Canada.
• DO NOT aach the gas line to the
water heater unl aer the supply
line pressure tesng 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)
Propane
Gas
Min. 8.0" W.C. (2.0 kPa)
Max. 14.0" W.C. (3.49 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
instrucons, local and state/provincial
codes, or in the absence of these
codes, the current edions of ANSI
Z223.1/NFPA 54, Naonal Fuel Gas
Code in the USA or B149.1, Natural
Gas and Propane Installaon Code in
Canada. Otherwise, ow capabilies
and output temperatures will be
limited. See Table 14 and Table 15 on
the following page.
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 aect 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 operaon.
• Inlet gas pressure must not exceed
the maximum values in Table 13; gas
pressure above the specied range
will cause dangerous operang con-
dions and damage the unit.
• If the gas supply pressure to the
heater is greater than the specied
maximum, a 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 instrucons.
Some manufacturers may require a
certain amount of straight pipe on
the outlet prior to any addional
ngs.
• The regulator must be sized for the
water heater's minimum to maxi-
mum input and provide the speci-
ed pressures that are listed on the
rang 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
connecon.
Gas Connecons
1
Use a 3/4 inch union to
connect gas piping to the
water heater's 3/4 inch male
NPT connecon.
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
installaon's length of 1/2 inch pipe,
then 3/4 inch piping is required.
2
Install a full port manual gas
shut-o valve between the
water heater and the gas
supply line.
3
When the gas connecons
are completed, it is necessary
to perform a gas leak test
either by applying soapy water to all
gas ngs and observing for bubbles
or by using a gas leak detecon
device.
• The water heater and its individual
shut-o valve must be disconnected
from the gas supply piping system
during any pressure tesng 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-
o valve during any pressure tesng
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 connecng to the gas
inlet.
36 • Residenal Gas Tankless Water Heater Use and Care Guide
The following tables and informaon are from ANSI Z223.1/NFPA 54:
Natural Gas Supply Piping
Maximum delivery capacity of cubic feet of gas per hour of IPS pipe carrying Natural Gas with 0.60 specic gravity based on
0.5" W.C. pressure drop. Based on Energy Content of 1,000 BTU/³, the water heater requires:
160 ³/hr for the TM-160, 180 ³/hr for the TM-180, and 199 ³/hr for the TM-199 model.
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
Propane Gas (L.P.) Supply Piping
Maximum Capacity of Propane (LP) Based on 11 in. W.C. supply pressure at a 0.5 in W.C. pressure drop.
Table 15: Propane Gas Supply Piping Unit: kBTU 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" 268 184 148 126 112 101 93 87 82 77 68 62 53
3/4" 567 393 315 267 237 217 196 185 173 162 146 132 112
1" 1,071 732 590 504 448 409 378 346 322 307 275 252 213
1-1/4" 2,205 1,496 1,212 1,039 913 834 771 724 677 630 567 511 440
1-1/2" 3,307 2,299 1,858 1,559 1,417 1,275 1,181 1,086 1,023 976 866 787 675
2" 6,221 4,331 3,465 2,992 2,646 2,394 2,205 2,047 1,921 1,811 1,606 1,496 1,260
Gas Sizing Example (Natural Gas)
Based on Energy Content of 1,000 BTU/³ (Figure 36):
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 36 to properly size the line.
For secons 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 secon, and size to the farthest appliance.
FOR EXAMPLE: The secon 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 ³ 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 , Secon A to B needs to be 1" in
order to supply 220 ³.
Water
Heater
199,000 BTU/h
A B
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 36 - Pipe Sizing Diagram
Water Connecons
WARNING! DO NOT use this
appliance if any part has been
under water. Immediately contact a
qualied installer or service agency
to replace a ooded water heater.
DO NOT aempt to repair the unit! It
must be replaced!
IMPORTANT: DO NOT reverse the hot
outlet and the cold inlet connecons
to the water heater. If you reverse the
connecons, the water heater will not
acvate properly.
Determine the type of water pipes in
your home. Use 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
ngs, valves and other components,
including soldering materials, must
be suitable for potable water system.
Also, an automac air vent or air
separator must be installed when
the water heater operates in a closed
loop system such as a recirculaon
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 instrucons.
A manual shut-o valve must be
installed on the cold water inlet to the
water heater between the main water
supply line and the water heater. In
addion, a manual shut-o valve is
also recommended on the hot water
outlet.
If the water heater is installed
within, or subjected to, a closed loop
water system, a thermal expansion
tank or code approved device to
handle thermal expansion must be
installed. Follow the expansion device
manufacturer's instrucons for proper
installaon and operaon.
NOTICE: If the plumbing system is
subject to water hammer, then it is
recommended that water hammer
arrestors be installed.
Making Water Connecons
IMPORTANT: Before installing the
water heater, ush the water line
to remove all debris, and aer
installaon is complete, purge the air
from the line. Failure to do so may
cause damage to the heater.
NOTICE: There is a wire mesh lter
within the cold inlet to trap debris
from entering your water heater. This
will need to be cleaned periodically to
maintain opmum ow.
The water inlet and outlet threaded
connecons are brass. When
connecng the unit to piping made of
a dierent material, use of a dielectric
ng or a dielectric union conforming
to ASSE 1079 is recommended to
prevent corrosion and potenal
subsequent water leaks at or near the
connecon. Dielectric ngs may be
required by local plumbing codes.
1
Connect the hot water supply
using 3/4 inch NPT to the
ng marked "HOT." Follow
the same connecon 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 ng on the
water heater.
3
Install insulaon (or heat
tape) on the water pipes
especially if the indoor
installaon area is subject to freezing
temperatures. Insulang 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 protecon 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
connecons or use compression
ngs which do not require
soldering. Compression ngs
are easier to install than soldering
pipe. Check with local plumbing
ocials to determine what types of
pipe materials are suitable for your
locaon. DO NOT use lead-based
solder.
NOTICE: DO NOT solder pipes while
they are aached 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 anmony or equivalent
solder.
2
Aach the threaded adapters
to the water heater's
connecons (using thread
sealant tape or pipe joint compound).
3
Connect the home's water
pipes by soldering, keeping
the connecons at the water
heater cool with wet rags.
Residenal Gas Tankless Water Heater Use and Care Guide • 37
INSTALLATION
38 • Residenal Gas Tankless Water Heater Use and Care Guide
X3® Technology
WARNING! DO NOT operate water
heater unl 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 potenal property damage.
This water heater may be equipped
with X3® Scale Prevenon Technology
to inhibit scale formaon within the
heat exchanger tubing of this unit.
Part of the X3® Technology’s an-
scale protecon 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 operaon
of the unit (shown as follows). X3®
Scale Prevenon Technology reduces
the formaon of scale in the heat
exchanger, extending the operang
life of the unit in typical potable water
installaons. Specic water condions
may impact the eciency 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 37 - X3® & Bypass Cartridges
X3® Cartridge Installaon
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 direcon. Align the
on the X3® cartridge with the
on the manifold (arrows will be back
facing for TM series heaters). When
inserng the X3® cartridge, push up
unl the screw holes align. The bypass
cartridge is not keyed and will install
in either direcon. Some resistance is
normal. See Figure 38 for reference.
A BB
A
B
B
ALIGN
X3
®
CARTRIDGE
MANIFOLD
ARROWS ARE FACING BACKSIDE
Figure 38 - X3® Cartridge Installaon
Insert and snug all three screws by
hand. Use a screwdriver to ghten the
two
B
screws rst and lastly ghten
the one
A
screw. DO NOT use a drill
or impact driver to ghten the screws.
X3® Cartridge Removal
1
Disconnect power to the
water heater by unplugging it
or by turning o 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 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-installaon. Note the order of the
screws when removing them.
Reference Figure 38.
5
Pull down to remove the X3®
Cartridge from the water
heater.
NOTICE: The X3® Cartridge will be full
of water. Use cauon not to lt the
cartridge unl the water has been
drained.
Bypass Cartridge
If the water heater is an M model,
conrm the Bypass cartridge has been
properly installed before operang
the water heater.
NOTICE: Bypass cartridge installs
the same way as the X3® cartridge,
however it is not keyed.
INSTALLATION
Residenal Gas Tankless Water Heater Use and Care Guide • 39
INSTALLATION
Pressure Relief Valve
WARNING! Hot water could be
released. Before operang the
pressure relief valve manually, check
that it will discharge in a safe place. If
water does not ow freely from the
end of the discharge pipe, turn the
gas supply and power OFF and call
a qualied person to determine the
cause.
Refer to the pressure relief valve
manufacturer's instrucons for
inspecon and maintenance
requirements.
The water heater has a high-
temperature shut-o 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
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.
Aach the discharge tube to the
pressure relief valve and run the
end of the tube to within 6 inches
(152 mm) from the oor for USA
installaons and 12 inches
(305 mm) for Canadian installaons.
This discharge tube must allow free
and complete drainage without any
restricons.
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
situaon.
WARNING! DO NOT plug the
pressure relief valve.
6" (152 mm)
Maximum USA
Discharge Pipe
12" (305 mm)
Maximum Canada
Figure 39 - Discharge Pipe Clearance
The pressure relief valve must be
manually operated periodically to
check for correct operaon. Before
operang 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 installaon must
follow local codes.
2
The discharge capacity must
be at least:
• 160,000 BTU/hr for TM-160 model
• 180,000 BTU/hr for TM-180 model
• 199,000 BTU/hr for TM-199 model
3
The pressure relief valve
needs to be rated for a
maximum of 150 psi.
Condensate Drain
Follow all code requirements of
the local authority on condensate
neutralizers and whether or not they
are required for installaon.
• Discharge condensate (acidic water)
in accordance with all local codes
and common safety pracces.
• 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 installaons
in which the drain is not directly
below the water heater.
• If a neutralizer is installed, a
eld-supplied overow bypass 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 ow of
condensaon.
• 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 ow freely. All
porons of the condensate drain
(neutralizer and drain tube) must be
at a lower elevaon than the water
heater to prevent condensate water
from building up inside the heat
exchanger.
• Condensate cannot be eecve-
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 applicaon
and usage. Replace the cartridge
when the condensate pH goes
below 6.0.
• All preventave measures and safety
pracces 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
protecon against water damage, is
recommended to be installed under
the water heater in case of leaks.
Recirculaon
When installing a recirculaon pump,
care must be taken to properly size
the pump for the applicaon. Sizing
must be performed by the installing
contractor or engineer. Below are
the requirements that need to be
followed when sizing:
NOTICE: Running the pump
connuously will reduce the warranty
of the water heater.
• Size the recirculaon pump to ow
no less than 2 gpm (7.6 L/min) and
no more than 4 gpm (15.1 L/min)
per heater acvaon. The manu-
facturer's suggested ow rate is 3
gpm (11.4 L/min). Refer to the water
heater's pressure drop chart on
its specicaon sheet for losses at
other ow rates. See Table 16 below
for potenal head loss.
Table 16: Head Loss
Cong. 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 eld supplied aquastat with
immersion probe and an adjustable
dierenal. The minimum suggested
dierenal is 15°F (8.3°C).
IMPORTANT: If the inlet water
thermistor in the water heater
measures the temperature of inlet
water above the temperature seng,
or above 122°F (50°C), the water
heater will shut down. In this scenario
the water heater will display code
E383.
• An air eliminaon device is suggest-
ed to remove air from the piping
system. Air may cause the recircu-
laon pump to cavitate and may
reduce the water ow rate. These
items should be installed per the
manufacturer's instrucons.
The installer will need to consider the
size of water tubing, material type,
and ngs when determining the
pressure drop of the system to size
the recirculaon pump.
NOTICE: These characteriscs vary
for each tubing material of the same
nominal size. Refer to the water
tubing manufacturer for pressure
drop informaon that is needed to
size the recirculaon pump. Check
with local codes and ordinances for
addional installaon requirements.
Point-of-use thermostac mixing
valves may be used with tankless
water heaters. Consult with the
point-of-use thermostac mixing valve
manufacturer for the appropriate
valve for the applicaon. Refer to the
point-of-use thermostac mixing valve
manufacturer for proper installaon
when recirculaon is in use.
WARNING! To reduce the risk
of unusually hot water reaching
the xtures in the house, install
Thermostac Mixing Valves at each
point-of-use.
NOTICE: Figure 40 on page 41
provides the manufacturer's
suggested piping layout for
recirculaon. The installer must
properly install the system per
manufacturer's instrucons and local
codes. Refer to the water heater
manufacturer's website for addional
layouts.
40 • Residenal 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
Figure 40 - Recommended Recirculaon Diagram
Residenal Gas Tankless Water Heater Use and Care Guide • 41
INSTALLATION
Electrical Connecons
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
aach 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
aached.
• The use of a surge protector is rec-
ommended in order to protect the
unit from power surges.
Plug-in Connecon
(Indoor & Outdoor Installs)
The water heater should be plugged
into a 120 VAC, 60 Hz ground
electrical outlet.
Hardwired Connecon
(Indoor & Outdoor Installs)
NOTICE: Follow the steps below if the
power supply must be hardwired to
the water heater. Otherwise, you may
skip this secon.
1
Remove and keep the two
screws securing the front
cover. Remove the cover.
2
Locate the system power cord
and cut the wires at the
locaon shown in Figure 41.
Cut Wires
Figure 41 - System power cord cut locaon.
3
Remove the screws securing
the power cord to the boom
of the water heater.
4
Remove the power cord from
the boom of the water
heater and install a strain
relief connector in the opening.
5
Make the electrical
connecon to the water
heater. Follow the electrical
code requirements of the local
authority having jurisdicon. In the
absence of local codes, follow the
current edion of the Naonal
Electrical Code ANSI/NFPA 70 in the
U.S. or the current edion of CSA
C22.1 Canadian Electrical Code Part 1
in Canada.
6
Verify all electrical
connecons 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 instrucons in the
Geng Started secon of this
manual.
Accessory Connecons
This system supports up to three
accessories connected in series.
NOTICE: If mulple water heaters
are used in a Cascade System, all
accessories must be connected in
series to the parent unit.
Follow the accessory kit instrucons
to access the control board.
Each accessory has both a ve-pin
female connector and a secon of
cable with a ve-pin male connector
on the end (see Figure 42). The male
connector connects to the control
board or to the next accessory in the
series. The ve-pin female connector
allows another accessory to connect
and create a series. Reference
Figure 42 when creang a series of
accessories.
If the length of the accessory cord
is not long enough, communicaon
cables can be purchased to extend the
length. These cables are available in
10 . (3 m) and 32 . (10 m) lengths.
Connect the single ve-pin connector
on the communicaon cable to the
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).
42 • Residenal Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Residenal Gas Tankless Water Heater Use and Care Guide • 43
INSTALLATION
Wi-Fi Module
Remote
Controller
Connecting Secondary AccessoryConnecting Primary Accessory
Indoor Wall
Indoor Wall
Accessory
5-Pin Female
Accessory
5-Pin Male
Secondary
Accessory
5-Pin Male
Printed Circuit Board
Secondary
5-Pin Connector
Primary
Primary
Accessory
5-Pin Male
Printed Circuit Board
Primary
5-Pin Connector
Accessory Connections
Figure 42 - Accessories Installed in Series
44 • Residenal Gas Tankless Water Heater Use and Care Guide
Cascade System
The Cascade System allows up to 12
heaters of the same input rate and
model to be linked in a Parent/Child
conguraon. DO NOT link heaters
of dierent input rates and models
together.
IMPORTANT: Failure to cascade
heaters of the same input rate and
model series will result in a system
error code.
The Cascade System will acvate
heaters based on the system ow
rate demand. When system demand
increases or decreases, the cascade
system will acvate/deacvate
heaters as needed to balance ow
through the heaters.
The Parent heater determines when
to acvate/deacvate heaters. The
order of heater acvaon is set by
the Parent heater and will sequence
the heaters in order from the least
combuson hours to the most. This
allows for even operaon of all the
water heaters in the cascade system.
The heaters will deacvate in the
reverse order that they are acvated,
meaning if Child Heater 11 was the
last to turn on, it will be the rst
to turn o when system demand
decreases. The Parent heater will
reorder the sequence on a weekly
basis.
The new sequence of acvaon will
start with the heater that has the
least combuson hours to the most.
Each heater will acvate based on
predetermined 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 connue to operate.
If the Parent heater loses power, then
the cascade system deacvates. The
user will need to change the sengs
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 congured with the Parent
water heater as either the
rst or last in the series of water
heaters connected to the cold water
supply. The Child units will follow
sequenally. See Figure 45.
2
Before proceeding,
disconnect electrical power
to all water heaters in the
Cascade conguraon.
3
Remove the front covers and
keep the two screws from
both the Parent and Child
water heaters for re-installaon.
4
Remove the two screws (top
and boom) securing the
control panel to the Parent
water heater. The control panel is
located on the boom right side of
the water heater as shown in Figure
43.
Remove
Screws (2x)
Control Panel for
Printed Circuit Board
ON/OFF
DOWN
UP
SETTING
Figure 43 - Control Panel Locaon
5
Gently slide control panel out
from the Parent water heater
to gain access to the Printed
Circuit Board (PCB). Proceed with
cauon and DO NOT disconnect wires
from PCB.
6
Use Figure 44 to locate the
rubber access grommet on
the boom of the water
heater. Route the single harness end
of the Cascade Linking Cable through
the boom 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 44 - Boom of water heater - Grommet
7
Use Figure 45 as a reference
to locate the connecon
point for the Parent Cascade
Unit. Use the single harness end of
the Cascade Linking Cable to make the
inial connecon.
8
Follow steps 4-6 to route the
double harness end of the
Cascade Linking Cable to the
printed circuit board on the 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 boom of
the rst Child water heater and
connect it to the open harness on the
rst Cascade Linking Cable as shown
in Figure 45.
INSTALLATION
Residenal Gas Tankless Water Heater Use and Care Guide • 45
10
Once all connecons are
made, the water heaters
must be assigned their
posion in the system. Turn on the
power supply to all of the water
heaters, making sure there is no water
ow.
11
On the Parent water heater
simultaneously press and
hold the "SETTING" and "UP"
buons unl C00 appears. See Table
27 on page 54.
12
Press the UP arrow buon to
reach the C13 opon, then
press the "SETTING" buon
to enter that opon.
NOTICE: C13 denes the number
of Child water heaters that will be
connected to the parent unit.
Enter the number of Child water
heaters aached to the parent water
heater and press the "SETTING"
buon 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" buon
again to return to normal operaon.
13
Aer the Parent water heater
is congured, the Child water
heaters must be congured.
Perform the following steps on each
Child water heater.
14
On each Child unit’s UIM,
press and hold both the
"SETTING" and "UP" buons
unl C00 appears.
15
Press the UP arrow buon to
reach the C14 opon, then
press the "SETTING" buon
to enter that opon.
NOTICE: C14 denes the number
assigned to each Child water heater
connected to the parent water heater.
16
Enter number 2 for the rst
Child water heater and press
the "SETTING" buon to load
the number to memory. Repeat this
step, assigning a sequenal number at
each addional Child water heater.
17
Press and hold the "SETTING"
buon again to return to
normal operaon.
NOTICE: A maximum 11 Child water
heaters can be connected to a
Cascade System of 12 total water
heaters.
18
Verify all electrical
connecons and conduit
connecons are secure.
19
Follow the instrucons in the
Geng Started secon of this
manual.
INSTALLATION
BUILDING
RETURN
PARENT UNIT
CWS
HWS
GAS
CHILD UNIT #1 CHILD UNIT #2
Single
Harness
End
Parent Unit PCB
3-Pin Connector
Double
Harness End
Child Unit PCB
Single
Harness
End
Figure 45 - Mul Unit Cascade Conguraon
46 • Residenal Gas Tankless Water Heater Use and Care Guide
FOR YOUR SAFETY,
READ BEFORE
OPERATING
WARNING! IF YOU SMELL GAS:
• DO NOT try to 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 instrucons.
• If you cannot reach your gas suppli-
er, call the re department.
• Failure to observe these warnings
could lead to re or an explosion,
resulng in severe injury or death.
✓ Check the GAS and WATER CON-
NECTIONS for leaks before ring
unit for the rst me.
✓ 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-
ied service technician. Forced re-
pair may result in a re or explosion
due to gas leaks.
✓ Be sure to check for the presence
of leaking gas toward the boom
of the unit because some gases
are heavier than air and may sele
towards the oor.
✓ Check the GAS PRESSURE. Refer to
the "Gas Supply and Gas Pipe Siz-
ing" secon starng on page 35.
✓ Check for PROPER VENTING and
COMBUSTIBLE AIR to the water
heater.
✓ Purge the GAS and WATER LINES to
remove any air pockets.
✓ DO NOT use this appliance if any
part has been under water. Immedi-
ately contact a qualied installer or
service agency to replace a ooded
water heater. DO NOT aempt to
repair the unit! It must be replaced!
Start-Up Instrucons
Read and understand these direcons
thoroughly before aempng to
start-up the water heater. Make sure
the water is plumbed correctly before
aempng to start-up the water
heater. Check the rang 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 rang plate. If you have any
quesons or doubts, consult your gas
supplier or gas ulity company.
NOTICE: A newly installed water
heater will have air in the gas line. It
may take several aempts 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
acvate the breaker/
disconnect, if the water heater is
hardwired.
3
The user interface will display
the current temperature
seng. The default is 120°F
(49°C).
4
To change the set point
temperature, press the "UP"
or "DOWN" buon to raise or
lower the outlet temperature. See the
"Temperature Sengs" secon on
page 49.
5
To set the heater to the
appropriate elevaon, vent
size and vent length, see
"Conguraon Mode (C Mode)"
starng on page 50.
Shut-Down Instrucons
Press the "ON/OFF" buon and wait
for the display to shut o.
NOTICE: The power buon on the
water heater and remote controller
DOES NOT disconnect power to the
water heater. You must physically
disconnect power to the water heater.
Emergency Shut-Down
Should overheang occur or the gas
supply fail to shut o, follow these
steps:
1
Turn OFF the gas supply to
the water heater at the
manual shut-o valve.
2
Press the "ON/OFF" buon
on the water heater.
3
Disconnect power to the
water heater by unplugging it
or by turning o the circuit at
the breaker box, as appropriate.
4
Call a qualied person
(licensed plumber, authorized
gas company personnel, or
authorized service technician) for
assistance.
OPERATION
Figure 46 - Lighng Instrucons
Residenal Gas Tankless Water Heater Use and Care Guide • 47
OPERATION
48 • Residenal Gas Tankless Water Heater Use and Care Guide
User Interface Module (UIM) & Remote Controller Display Overview
ON/OFF
DOWN
UP SETTING
E
F
G
H
B
A
C
D
Figure 47 - UIM & Remote Controller Display Diagram
Table 17: UIM & Remote Controller Display
Item Descripon
A Water Flow Detected
B Flame Detected
C Up Buon
D Down Buon
E Display
F Standby Mode
G Seng Buon
H Operaon ON/OFF Buon
OPERATION
Residenal Gas Tankless Water Heater Use and Care Guide • 49
OPERATION
Temperature Sengs
With the installaon steps completed, you may adjust the water heater's temperature seng 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" buon or the "DOWN" buon. To set the water heater to a temperature above 125°F (52°C), follow the procedure as
outlined in Table 18:
Table 18: Set Temperature Above 125°F (52°C)
Operaon Screen on the Controller (Built-in & Remote)
1. Turn on the 120 VAC power supply to the unit.
2.
Press the "ON/OFF" buon 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" buon for 5 seconds to access the
water heater Adjustment Mode (A Mode).
LONG PRESS
SETTING
5.
The display will ash between code "A00" and the current set
temperature. Short press the "SETTING" buon to access the
temperature seng. The temperature only will ash.
SHORT PRESS
SETTING
6.
Press the "UP" buon and the "DOWN" buon to select the
desired set point temperature. See Table 19 below for available
set point temperatures.
UP
DOWN
7. Short press the "SETTING" buon again to execute the change.
SHORT PRESS
SETTING
8.
Press and hold the "SETTING" buon for 5 seconds to return the
display to normal operaon. The new temperature set point will
appear (Example: 130°F).
Table 19: 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 seng (Default): 120°F (49°C).
50 • Residenal Gas Tankless Water Heater Use and Care Guide
OPERATION
Conguraon Mode (C Mode)
The water heater must be congured based on the installaon applicaon. If the installaon meets all of the “Default” criteria
listed, then no adjustments are necessary. Follow the procedure below to access C Mode and to properly congure the water
heater:
1. Press and hold the "UP" buon and the "SETTING" buon for 5 seconds to access C Mode.
2. Press the "UP" buon or the "DOWN" buon to search for the desired C Code.
3. Press the "SETTING" buon to adjust the value. The current value will ash. Use the "UP" and "DOWN" buons to adjust
the seng to the value listed in the applicable table below.
4. Press the "SETTING" buon again to conrm the new value selected is correct.
5. To adjust addional modes, press the "UP" buon or the "DOWN" buon to search for the desired C Mode. To exit C Mode,
press and hold the "UP" buon and the "SETTING" buon for 5 seconds.
IMPORTANT: If any C08 (Vent Type) value is selected and conrmed, the User Interface Module will display the water heater
model number preceded by a dash. The water heater MUST be disconnected at the power supply and reconnected to save the
C08 selecon. This acon may take place aer all conguraon adjustments are complete.
Table 20: C Mode Altude Sengs (C01)
Code Descripon Seng Indoor Outdoor Conguraon Opons
C01 Altude Sengs
0 Default Default 0 to 2,000 . (0 to 610 m) Elevaon
1 Available Available 2,001 to 5,400 . (611 to 1,645 m) Elevaon*
2 Available N/A 5,401 to 7,800 . (1,646 to 2,377 m) Elevaon*
Notes for Proper Conguraon (Indoor/Outdoor)
1) C01 (Altude) MUST be adjusted before C08 (Vent Type) and C02 (Vent Length).
2) The Exhaust Vent for Outdoor Installaon does not require further adjustment to C08 (Vent Type) or C02 (Vent Length).
3) If your applicaon meets the Default criteria, then no adjustment to C01 (Altude) is required.
*High altude vent sengs above 2000 feet (609 m) will impact some vent length sengs. See Table 24 and Table 26.
Table 21: C Mode Vent Size (C08)
Code Descripon Seng Indoor Conguraon Opons
C08 Vent Size
2 Default 2 Inch
3 Available 3 Inch
Notes for Proper Conguraon (Indoor)
1) C08 (Vent Type) MUST be adjusted before C02 (Vent Length).
2) When C01 (Altude) is set to 0, C08 (Vent Type) will default to seng 2 and cannot be adjusted.
3) When C01 (Altude) is set to either 1 or 2, select the appropriate C08 (Vent Type) value based on the listed venng above.
4) If your applicaon meets the Default criteria, then no adjustment to C08 (Vent Type) is required.
Table 22: C Mode Gas Type (C03)
Code Descripon Seng Conguraon Factory Set by Manufacturer*
C03 Gas Type
0 Natural Gas
1 Propane
Notes for Proper Conguraon
*C03 (Gas Type) is factory set by the manufacturer and shall not be adjusted in the eld. This table is for reference only.
Residenal Gas Tankless Water Heater Use and Care Guide • 51
OPERATION
Calculang Vent Length
Before operang the water heater, you must determine the correct vent length seng for your applicaon. Reference
Table 8 (page 22), Table 10 & Table 11 (starng on page 26) to calculate the total vent length for your applicaon. Once the
total vent length has been determined, use Table 23 through Table 26 on the following pages to idenfy the correct C02 seng.
Example:
Venlaon Component Type Equivalent Length
The example to the le assumes a 199k
model, Power Direct Vent installaon
with 2 inch Polypropylene venng at sea
level for Natural Gas. Using Table 23 on
the following page, the appropriate C02
seng for 24 feet (7.3 m) of venng is
C02 = 2.
Elbows (Table 8) (1x) 87° Elbow 3 . (0.9 m)
Terminaon (Tables 9 & 10) Polypropylene (2" Low Prole) 6 . (1.8 m)
Horizontal Vent Run Polypropylene 12 . (3.7 m)
Vercal Vent Run Polypropylene 3 . (0.9 m)
Total Vent Length: 24 . (7.3 m)
Your Applicaon:
Venlaon Component Type Equivalent Length
Use your total length and the informaon
found in the vent length tables
(depending on model and elevaon) on
the following pages to determine the
correct vent length seng based on your
applicaon.
Elbows (Table 8)
Terminaon (Tables 9 & 10)
Horizontal Vent Run
Vercal Vent Run
Total Vent Length:
Venlaon Component Type Equivalent Length
Use this table for addional water heaters
used in a Cascade System.
Elbows (Table 8)
Terminaon (Tables 9 & 10)
Horizontal Vent Run
Vercal Vent Run
Total Vent Length:
Venlaon Component Type Equivalent Length
Use this table for addional water heaters
used in a Cascade System.
Elbows (Table 8)
Terminaon (Tables 9 & 10)
Horizontal Vent Run
Vercal Vent Run
Total Vent Length:
Venlaon Component Type Equivalent Length
Use this table for addional water heaters
used in a Cascade System.
Elbows (Table 8)
Terminaon (Tables 9 & 10)
Horizontal Vent Run
Vercal Vent Run
Total Vent Length:
52 • Residenal Gas Water Heater Use and Care Guide
OPERATION
Vent Length Conguraon (C02) for Natural Gas
The tables below describe C Mode vent length conguraon based on altude for Natural Gas:
Table 23: C Mode Vent Length Conguraon (C02) for 0-2,000 . (0-610 m) Altude, Natural Gas
Code
Vent
Material
Vent
Size
Vent
Conguraon
Controller Seng (199k/180k/160k Models)
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 24: C Mode Vent Length Conguraon (C02) for 2,001 to 7800 . (611 to 2,377 m) Altude, Natural Gas
Code
Vent
Material
Vent
Size
Vent
Conguraon
Controller Seng (199k/180k/160k Models)
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)
Residenal Gas Water Heater Use and Care Guide • 53
OPERATION
Vent Length Conguraon (C02) for Propane
The tables below describe C Mode vent length conguraon based on altude for Propane:
Table 25: C Mode Vent Length Conguraon (C02) for 0-2,000 . (0-610 m) Altude, Propane
Code
Vent
Material
Vent
Size
Vent
Conguraon
Controller Seng (199k/180k/160k Models)
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)
40-44 .
(12.0-13.4 m)
45-50 .
(13.5-15.2 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 26: C Mode Vent Length Conguraon (C02) for 2,001 to 7800 . (611 to 2,377 m) Altude, Propane
*For water heaters based on altude of 5,401 to 7,800 . (1646 to 2,377 m) only.
Code
Vent
Material
Vent
Size
Vent
Conguraon
Controller Seng (199k/180k/160k Models)
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
4-30 .
(1.2-9.1 m)
31-70 .
(9.2-21.3 m)
71-150 .
(21.4-45.7 m)
141-150 .*
(42.7-45.7 m)
71-140 .*
(21.4-42.6 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)
54 • Residenal Gas Tankless Water Heater Use and Care Guide
Cascade Conguraon
Use Table 27 below to congure water heaters installed in a Cascade System. See the "Cascade System" secon starng on
page 44 for more informaon on installaon and conguraon.
IMPORTANT: Each water heater must be properly congured for Altude (C01), Vent Type (C08) and Vent Length (C02) before
linking the units in the Cascade system.
Table 27: C Mode Cascade System (C13 & C14)
Code Descripon Seng Conguraon Opons
C13 Number of Child Units in Cascade System
0:
1-11:
No Cascade System (default).
Idenfy number of Child Units. This acvates 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 seng is changed. Follow this
procedure to change this seng:
Table 28: Convert Units
Operaon Screen on the Controller (Built-in & Remote)
1.
Turn on the 120 VAC power supply to the unit. Press the "ON/
OFF" buon on the controller in order to turn the controller on.
ON/OFF
2.
The set point temperature will display. Press and hold the
"SETTING" buon for 5 seconds to access the water heater
Adjustment Mode (A Mode).
LONG PRESS
SETTING
3.
The display will ash between code "A00" and the current set
temperature. Press the "UP" or "DOWN" buon once and the
display will show code "A01." Short press the "SETTING" buon
to show the current temperature seng. The temperature will
ash.
SHORT PRESS
SETTING
4.
Press the "UP" buon and the "DOWN" buon to alternate
between Fahrenheit and Celsius.
UP
DOWN
5. Short press the "SETTING" buon again to execute the change.
SHORT PRESS
SETTING
6.
Long press the "SETTING" to return the display to normal
operaon. The new temperature set point will appear in the
selected unit (Example: 49°C).
OPERATION
Residenal Gas Tankless Water Heater Use and Care Guide • 55
MAINTENANCE
Regular Maintenance
WARNING! Turn OFF the electrical
power supply and close the manual
gas shut-o valve and the manual
water control valve before servicing.
Failure to do so could result in
serious personal injury or death.
Roune maintenance will help your
water heater last longer and work
beer. Failure to perform required or
recommended maintenance may void
the warranty. If you cannot perform
these roune maintenance tasks
yourself, contact a qualied person:
The manufacturer recommends
having the unit checked once a year or
as necessary by a licensed technician
or qualied person. If repairs are
needed, any repairs should be done
by a licensed technician.
• Clean the cold-water inlet lter.
• The intake and venng system
should be checked annually for any
leaks, corrosion, blockages, or dam-
age. Replace any damaged secon
of venng and clear any blockage.
• The venng system should be
checked annually for any leaks,
corrosion, blockages or damage.
Replace any damaged secon of
venng and clear any blockages.
• Keep the area around the water
heater and terminaons clear. Reg-
ularly ensure that the area around
the water heater, vent terminaon,
and air intake is free from dust,
debris, and other contaminants.
Remove any combusble materials,
gasoline, 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 situaon.
• The pressure relief valve must be
manually operated periodically to
check for correct operaon. Before
operang 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 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 operang burner should pro-
duce clear, blue, stable ames. The
ames should not be liing above
the burner. Contaminated air may
cause a discolored ame. Contact a
qualied technician if the ame is
not sasfactory. See Figure 48 below
for burner ame reference.
Blue Flame
Satisfactory
Flame lifting
above the
burner
Unsatisfactory
Figure 48 - Check Burner Flames
Freeze Protecon
System
This unit comes equipped with
heang blocks to protect it from
damage associated with freezing. The
auto-re mode acvates the burner
for a short period of me.
For this freeze protecon 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 preventave 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
protecon 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
Protecon 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 condions:
1
Completely drain the water
out of the unit. See the "Unit
Draining & Power Outage
(Freeze Protecon)" secon on page
56.
2
Disconnect power to your
water heater.
56 • Residenal Gas Tankless Water Heater Use and Care Guide
Unit Draining &
Power Outage (Freeze
Protecon)
1
Close the manual gas shut-o
valve.
2
Disconnect power to the
water heater by unplugging it
or by turning o 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 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
operaon, reinstall the X3®
Cartridge with 3 screws
removed earlier. For detailed
instrucons see “X3® Cartridge
Installaon” on page 38.
9
Open the cold inlet water
valve. Check all water
connecons for leaks. If leaks
are found, shut o the cold water
inlet valve and immediately 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-o
to the water heater.
12
If the set temperature is not
displayed, press the ON/OFF
buon.
NOTICE: If any errors occur, shut o
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 lter is clogged, water
will not be supplied to the
water heater properly.
Inlet Water Filter
1
Close the manual gas shut-o
valve.
2
Disconnect power to the
water heater by unplugging it
or by turning o 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 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 lter
and remove it from the water
heater.
8
Clean the lter: Check the
water lter located within the
cold inlet. With a ny brush,
clean the water lter of any debris
which may have accumulated.
9
Screw the inlet water 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
operaon, reinstall the X3®
Cartridge with 3 screws
removed earlier. For detailed
instrucons see “X3® Cartridge
Installaon” 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 connecons will be
apparent. Correct any leaks
immediately.
12
Turn ON the gas supply to the
water heater at the manual
gas shut o valve.
13
Restore power to the water
heater. The water heater is
now ready for operaon.
MAINTENANCE
Residenal Gas Tankless Water Heater Use and Care Guide • 57
TROUBLESHOOTING
General Troubleshoong
If the water heater is experiencing issues, please check the following. Aer checking, consult with a qualied person.
Table 29: Troubleshoong Chart
Problem Soluons
Temperature and Amount of Hot Water
It takes a long me to get hot water
at the xtures.
• The mes it takes to deliver hot water from the water heater to your 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 xtures more quickly, you may
want to consider a hot water recirculaon 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 sucient?
• 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 xture is opened.
• Make sure the unit has 120 VAC, 60 Hz power supply and power frequency is
set to 60 hz.
• Verify the operaon seng 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-
eraon seng is ON. If the display is blank and nothing appears when pressing
the UP buon, then the operaon state is set to OFF. Press the ON/OFF buon
to acvate 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 lter on the cold water inlet clean?
• Is the hot water xture suciently 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 ow rate enough to keep the water heater running?
• If there is a recirculaon system installed, does the recirculaon line have
enough check valves?
• Is the gas supply valve fully open?
• Is the lter on the cold water inlet clean?
• Are the xtures clean of debris and obstrucons?
Fluctuaon in hot water
temperature.
• Is the lter on the cold water inlet clean?
• Is the gas line sized properly?
• Is the gas supply pressure sucient?
• Check for cross connecon between cold water lines and hot water lines.
• If cascaded with mulple heaters, inspect and verify each heater is operang
properly within the cascade system.
58 • Residenal Gas Tankless Water Heater Use and Care Guide
Table 29: Troubleshoong Chart
Problem Soluons
Water Heater
Unit does not ignite when water
goes through the unit.
• Is the ow rate over 0.4 GPM (1.5 L/min)?
• Check the lter on the cold water inlet.
• Check for reverse connecons and cross connecon.
• If you use the remote controller and/or built-in controller, is the power buon
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 acvate.
The fan motor is sll spinning aer
operaon has stopped.
• This is normal. Aer operaon has stopped, the fan motor keeps running to
re-ignite quickly, as well as to purge all the exhaust gas out of the ue.
Unit sounds abnormal while in
operaon.
• Check all venng and terminaons for any blockage and clear.
• If other exhaust terminaons are nearby, conrm ue gases are not sucked into
the water heater's air intake.
• Contact Technical Support Department.
TROUBLESHOOTING
Residenal Gas Tankless Water Heater Use and Care Guide • 59
TROUBLESHOOTING
Error Codes
The water heater has self-diagnosc
funcons for safety and convenience
when troubleshoong.
If there is a problem with the
installaon or the unit, the error code
associated with that failure will be
displayed on the built-in controller or
remote controller.
Consult Table 30 on the following
pages for the descripon of each error
code.
Single Unit Installaon
(Example)
If your water heater has the "E002"
error code (which signies a high limit
break):
• Indicator on the built-in and/or
remote controller will display "E002"
on the screen.
Figure 49 - Single Unit Error Code Example
Cascade System
(Example)
Error codes will be displayed
dierently 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 signies a high limit break):
• Indicator on the built-in and/or
remote controller of Parent unit will
intermiently ash "E002" and "2."
Figure 50 - Cascade System Error Code Example
(Parent Unit)
• Child unit #2 will intermiently ash
"E002" on the display.
Figure 51 - Cascade System Error Code Example
(Child Unit)
• Child unit #3 & #4 will not display
anything, as the error code does not
pertain to them.
60 • Residenal 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. Aer checking, consult with the manufacturer.
Table 30: Error Code Fault Analysis
Error
Code
Error Descripon Procedure
E002 High Limit Break
Manual Hi-Limit Switch located on heat exchanger tripped. Check Hi-limit switch
for proper operaon. Pressing the reset buon (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
reseng it. If the high limit switch connues to trip, contact a qualied service
technician.
E006
PCB Hardware Fault - AD
Converter Fault
Check PCB wiring for loose, damaged or cut wires/connectors. Correct any loose
connecon 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 instrucons on page 50 to access C Mode. Conrm C07 displays
60. If the seng is correct and the error sll occurs, contact a qualied service
technician.
E011
PCB Hardware Fault - Memory
Error
The water heater will connue to operate while this error code is ashing. If this
heater is part of a cascade system, then the system will be aected based on the
heater’s seng.
• Parent Heater: The cascade system will not operate. Remove this heater from the
cascade system and set a dierent heater as the Parent.
• Child Heater: This heater will not operate. The rest of the cascade system will
connue to run.
E036 Flame Failure
WARNING! Working on an energized circuit can result in severe injury or death
from electrical shock.
Check the ame sensor wire for a short or disconnecon. Correct any loose
connecon and replace any damaged wire/connector. If the error sll occurs,
contact a qualied service technician.
E037
False Flame Detecon
(During Standby)
WARNING! Working on an energized circuit can result in severe injury or death
from electrical shock.
1. Check for a visible ame through the sight glass while water is not running
through the water heater. If the error sll occurs, immediately shut o the
water heater and contact a qualied service technician.
2. Check the ame sensor wire for a short or disconnecon. Correct any loose
connecon and replace any damaged wire/connector. If the error sll occurs,
contact a qualied service technician.
TROUBLESHOOTING
Residenal Gas Tankless Water Heater Use and Care Guide • 61
TROUBLESHOOTING
Table 30: Error Code Fault Analysis
Error
Code
Error Descripon Procedure
E038 Ignion Failure
WARNING! Working on an energized circuit can result in severe injury or death
from electrical shock.
1. Check for a visible ame through the sight glass.
2. Check the ame sensor wire for a short or disconnecon. Correct any loose
connecon and replace any damaged wire/connector. If the error sll occurs,
contact a qualied 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 sll occurs, contact a qualied 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 disconnecon. Correct any
loose connecon and replace any damaged wire/connector. If the error sll
occurs, contact a qualied 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 disconnecon. Correct any
loose connecon and replace any damaged wire/connector. If the error sll
occurs, contact a qualied 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 disconnecon. Correct any
loose connecon and replace any damaged wire/connector. If the error sll
occurs, contact a qualied 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 disconnecon. Correct any
loose connecon and replace any damaged wire/connector. If the error sll
occurs, contact a qualied service technician.
E381 Combuson Blockage
1. With the water heater power disconnected, check the exhaust vent and air
intake piping for any blockages. Remove any blockages.
2. Verify the water heater has sucient combuson air. Reference the Combus-
on and Venng Installaon secon of the manual.
3. If the error sll occurs, contact a qualied service technician.
62 • Residenal Gas Tankless Water Heater Use and Care Guide
Table 30: Error Code Fault Analysis
Error
Code
Error Descripon Procedure
E382
Abnormal Proporonal Valve
Current
Check the proporonal valve wiring. Correct any loose connecon and replace
any damaged wire/connector. If the error sll occurs, contact a qualied service
technician.
E383 Inlet Water Over-temp
1. Verify the inlet water temperature is not above the water heater's set tempera-
ture or above 122°F (50°C).
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 disconnecon. Correct any
loose connecon and replace any damaged wire/connector. If the error sll
occurs, contact a qualied service technician.
E385
Main Gas Solenoid Valve Drive
Circuit Failure
Check the gas valve wiring. Correct any loose connecon and replace any damaged
wire/connector. If the error sll occurs, contact a qualied service technician.
E388 Bypass Valve Fault
1. Correct any loose connecon and replace any damaged wire/connector.
2. Follow the draining procedure on page 56 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 Contact a qualied service technician to replace the PCB.
E390
Fan Over Max Current
(During Standby)
Check the fan motor wiring. Correct any loose connecon and replace any damaged
wire/connector. If the error sll occurs, contact a qualied service technician.
E391
Fan Over Max Current
(During Operaon)
Check the fan motor wiring. Correct any loose connecon and replace any damaged
wire/connector. If the error sll occurs, contact a qualied service technician.
E392
Fan False Start
(During Operaon)
Check the fan motor wiring. Correct any loose connecon and replace any damaged
wire/connector. If the error sll occurs, contact a qualied service technician.
E393 Fan Signal Loss
Check the fan motor wiring. Correct any loose connecon and replace any damaged
wire/connector. If the error sll occurs, contact a qualied service technician.
E394 Fan Target Speed
1. Check the fan motor wiring. Correct any loose connecon and replace any dam-
aged 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 sll occurs,
contact a qualied service technician.
E395
Fan Current without Drive
(During Standby)
Check the fan motor wiring. Correct any loose connecon and replace any damaged
wire/connector. If the error sll occurs, contact a qualied service technician.
TROUBLESHOOTING
Residenal Gas Tankless Water Heater Use and Care Guide • 63
Table 30: Error Code Fault Analysis
Error
Code
Error Descripon Procedure
E400 Communicaon Fault with UIM
Check the UIM wiring. Correct any loose connecon and replace any damaged wire/
connector. If the error sll occurs, contact a qualied service technician.
E401
Communicaon Fault with
Remote Controller
1. Check the Remote Controller wiring. Correct any loose connecons and replace
any damaged wire/connector.
2. Only one remote controller can be installed, remove any addional remote
controllers.
3. If the error sll occurs, contact a qualied service technician.
E402
Communicaon Fault in
Cascade System
1. Check the Cascade wiring. Correct any loose connecons and replace any dam-
aged wire/connector.
2. Cycle the heater’s power OFF/ON if the cascade wiring was disconnected while
the system sll had power.
3. If the error sll occurs, contact a qualied service technician.
E404
Inconsistent Models in
Cascade-Link
Conrm 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 qualied service technician to replace the PCB.
E413 Flame Sensor Fault
1. Check the ame sensor wire for a short or disconnecon. Correct any loose
connecon 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 sucient combuson air. Reference the Combus-
on and Venng Installaon secon of the manual.
4. Check the installaon area for corrosive elements. Reference the Installaon
Environment secon in the manual.
5. If the error sll occurs, contact a qualied service technician.
E414 PCB - Flame Sensor Circuit
1. Check the ame sensor wire for a short or disconnecon. Correct any loose
connecon and replace any damaged wire/connector.
2. If the error sll occurs, contact a qualied service technician to replace the PCB.
E416 Analog/Digital (AD) Value Fault
1. Check the outlet thermistor sensor wire for a short or disconnecon. Correct
any loose connecons and replace any damaged wire/connector. If the error
sll occurs, contact a qualied 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 sll occurs, contact a qualied service technician to replace the PCB.
TROUBLESHOOTING
64 • Residenal Gas Tankless Water Heater Use and Care Guide
Table 30: Error Code Fault Analysis
Error
Code
Error Descripon 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 sll occurs, contact a qualied service technician.
E419 Flame Signal Lost
1. Check the ame sensor wire for a short or disconnecon. Correct any loose
connecon 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 sll occurs,
contact a qualied service technician.
3. If the error sll occurs, contact a qualied service technician.
E426 Condensate Drain Overow
1. Place a bucket under the water heater to catch any water.
2. With the water heater o, check the condensate drain for any blockages. Re-
move any blockages.
3. Check the condensate drain wires for a short or disconnecon. Correct any
loose connecon and replace any damaged wire/connector.
4. Verify the condensate drain line is installed correctly (reference page 39).
E427 Flow Control Valve
1. Check the ow control valve wires for a short or disconnecon. Correct any
loose connecons and replace any damaged wire/connector.
2. Remove the ow control valve and inspect for any debris or damage. Replace
if needed. First follow the draining procedure in the Unit Draining & Power
Outage secon in this manual.
E428 Flow Sensor - Cascade Only
1. Verify the water heater’s operaon is enabled. The heater’s UIM will display
the set temperature when enabled. If it is disabled, press the heater’s ON/OFF
buon to enable the heater’s operaon.
2. Verify that the heater’s water shuto valves are open.
3. Check the ow sensor wires for a short or disconnecon. Correct any loose
connecons and replace any damaged wire/connector.
4. Drain the water heater following Unit Draining & Power Outage secon in this
manual.
5. Remove the ow sensor and inspect for any debris or damage. Replace if need-
ed.
6. Remove and clean the inlet water lter.
TROUBLESHOOTING
Residenal Gas Tankless Water Heater Use and Care Guide • 65
Table 30: Error Code Fault Analysis
Error
Code
Error Descripon Procedure
E429
Flow Control Valve Fault -
Cascade Only
1. Check the ow control valve wires for a short or disconnecon. Correct any
loose connecons and replace any damaged wire/connector.
2. Remove the ow control valve and inspect for any debris or damage. Replace
if needed. First follow the draining procedure in the Unit Draining & Power
Outage secon in this manual.
TROUBLESHOOTING
66 • Residenal Gas Tankless Water Heater Use and Care Guide
Internal Component View (A)
1
9
2
7
8
6
4
11
3
13
5
10
12
COMPONENT LIST
Residenal Gas Tankless Water Heater Use and Care Guide • 67
Internal Component View (B)
17
18
14
19
16
15
22
23
20
21
COMPONENT LIST
68 • Residenal Gas Water Heater Use and Care Guide
External Component View
24
24
31
25
26
33
34
35
36
27
28
29
25
32
30
COMPONENT LIST
Residenal Gas Water Heater Use and Care Guide • 69
COMPONENT LIST
Internal / External Component List
When ordering repair parts, always give the following
informaon:
1. Model, serial, and product number. This info should be
on the le side of the water heater.
2. Item number.
3. Parts descripon.
Table 31: Internal / External Component List
Item Number Component List
1 Water Tube Retainer Clip
2 Freeze Protecon
3 Bypass Water Valve
4 Blower
5 Condensate Trap
6 Main Water Valve
7 Condensate Drain Connecon
8 Heat Exchanger Drain Connecon
9 Pressure Relief Valve
10 Secondary Heat Exchanger
11 Burner
12 Gas Manifold
13 Gas Manifold Cover
14 Condensate Tubing
15 Flame Sensor Rod
16 Ignitor Rod
17 Hot Water Outlet
18 Cold Water Inlet
19 Hi-Limit Switch
20 Primary Heat Exchanger
21 Ignitor Assembly
22 Gas Valve
23 3/4" Gas Connecon
Table 31: Internal / External Component List
Item Number Component List
24 Flue & Air Intake O-Ring
25 Flue & Air Intake Clamp
26 Intake Connecon
27 Cartridge Manifold (X3® or Bypass)
28 Bypass Cartridge
29 X3® Cartridge
30 Exhaust Connecon
31 Emission Port Cap
32 Outdoor Vent Cap*
33 Printed Circuit Board (PCB)
34 Front Cover
35 User Interface Module (UIM) Cover*
36 User Interface Module (UIM)
*Components for outdoor applicaons only.
Electrical Wiring Diagram
ANTI-FREEZE
ANTI-FREEZE
SWITCH
10W10W10W
10W10W25W25W
120 VAC POWER
L N
CN1
EARTH
CN2
L
N
EARTH
CN0
MAGNETIC
RING
120 VAC
POWER
PE
N
L
CN6
M
MAIN
WATER
VALVE
BYPASS
WATER
VALVE
M
CN7
PROPORTIONAL
VALVE
+
-
1
2
THERMAL FUSEHIGH LIMIT
CON2
MAIN VALVE
VALVE C
VALVE B
VALVE A
VALVE D
24V
IGNITOR
IGNITOR
ROD
INGI
GND
VAL_D
VAL_C
VAL_B
VAL_A
MAIN_V
24V
24V_IN
24V_OUT
P_VAL-
P_VAL+
24V
GROUND
FLAME1
GROUND
GROUND
FLAME
SENSOR
CN5
CASCADE
CN8CN9
CN4
M
FAN
DISPLAY
FERRITE
BEAD
(OR OTHER COMMUNCATION
EQUIPMENT)
RESERVED
FERRITE
BEAD
CON1
LIQUID
LEVEL
SWITCH
INLET WATER
TEMPERATURE
OUTLET WATER
TEMPERATURE
SMOKE
TEMPERATURE
HEAT EXCHANGER
TEMPERATURE
WATER FLOW
SENSOR
1
2
3
5V
5V
(OR OTHER COMMUNCATION
EQUIPMENT)
70 • Residenal Gas Water Heater Use and Care Guide
APPENDIX
Residenal Gas Water Heater Use and Care Guide • 71
APPENDIX
Flow Rate Capacity Chart
The chart is based on a properly sized gas line and installaon at 0-2,000 . (0-610 m). The water heater will derate
approximately 4% per 1,000 . (305 m) of elevaon 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
Copyright © 2026, A.O. Smith.
All Rights Reserved
