Installaon Instrucons and
Use & Care Guide
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. 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, and other
property, and present risks including re, scalding, electric shock, and explosion, causing
serious injury or death.
Commercial Gas
Tankless Water Heaters
Commercial On-Demand Gas Tankless Water Heaters
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.
MODEL:
CTH-199M
LOW LEAD
C
O
NTENT
100401602_2000854752B
May 2026
2 • Commercial Tankless Gas Water Heater Use and Care Guide
TABLE OF CONTENT
WATER HEATER BASICS ....................................................................................4
COMPONENT VIEW .................................................................................................................................. 4
TYPICAL INSTALLATIONS ............................................................................................................................ 5
DIMENSIONS ............................................................................................................................................. 6
SUPPLY CONNECTIONS .............................................................................................................................. 7
SPECIFICATIONS ......................................................................................................................................... 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
INSTALLATION................................................................................................17
Installaon Environment ......................................................................................................................... 17
Unit Clearances ....................................................................................................................................... 17
Mounng the Water Heater ................................................................................................................... 17
Combuson Air and Venng Installaon ................................................................................................. 18
Venng .................................................................................................................................................... 21
Installing the Vent Pipe ........................................................................................................................... 23
Exhaust Vent for Indoor Installaon ........................................................................................................ 23
Typical Venng Conguraons: .............................................................................................................. 24
Common Venng ..................................................................................................................................... 28
Clearances for Sidewall Terminaons ..................................................................................................... 33
Clearances for Rooop Terminaons ...................................................................................................... 34
Exhaust Venng for Outdoor Installaon ................................................................................................ 37
Outdoor Available Accessories ................................................................................................................ 37
Gas Supply and Gas Pipe Sizing ............................................................................................................... 38
Gas Conversion Restricon ...................................................................................................................... 40
Water Connecons .................................................................................................................................. 40
Recirculaon ........................................................................................................................................... 41
Combinaon Potable Water and Space Heang ..................................................................................... 42
Commercial Gas Tankless Water Heater Use and Care Guide • 3
TABLE OF CONTENTS
Dual Purpose Water Heang for the State of Massachuses ................................................................. 43
Water Quality .......................................................................................................................................... 44
Pressure Relief Valve ............................................................................................................................... 45
Condensate Drain .................................................................................................................................... 45
Electrical Connecons ............................................................................................................................. 46
Cascade System ....................................................................................................................................... 47
OPERATION ................................................................................................... 48
Accessory Connecons ............................................................................................................................ 49
FOR YOUR SAFETY, READ BEFORE OPERATING ........................................................................................ 50
Start-up Instrucons ................................................................................................................................ 50
Shut-Down Instrucons ........................................................................................................................... 50
Emergency Shut-Down ............................................................................................................................ 50
Temperature Adjustment/Seng the Temperature ................................................................................ 53
Unit Conversion Mode ............................................................................................................................. 54
Conguraon Mode (A Mode) ................................................................................................................ 55
Conguraon Mode (C Mode) ................................................................................................................ 56
Conguraon Mode (P Mode) ................................................................................................................ 57
MAINTENANCE ..............................................................................................58
THIS PAGE INTENTIONALLY LEFT BLANK .................................................................................................. 59
Regular Maintenance .............................................................................................................................. 60
Unit Draining & Power Outage
(Freeze Protecon) ................................................................................................................................. 61
Condensate Drain .................................................................................................................................... 61
Inlet Water Filter ..................................................................................................................................... 61
Bypass Cartridge ..................................................................................................................................... 64
General Troubleshoong ......................................................................................................................... 65
Error Codes .............................................................................................................................................. 66
Fault Analysis of Error Codes ................................................................................................................... 66
TROUBLESHOOTING .....................................................................................72
COMPONENT LIST ..........................................................................................73
FLOW RATE CAPACITY CHART .........................................................................78
GPM VS PRESSURE LOSS CHART .....................................................................79
4 • Commercial Gas Tankless Water Heater Use and Care Guide
WATER HEATER BASICS
Control Display
Printed Circuit Board
Gas Valve
Fan Motor Assembly
Exhaust Port
Inlet Port
Igniter Rod
Flame Sensor
Gas Valve
Venturi Assembly
Flow Sensor Control
Valve Assembly
Igniter
Condensate Trap
Air Pressure Switch
Bypass Valve
Burner Assembly
Pressure Relief Valve
(Field Supplied)
Bypass Cartridge
Heat Exchanger
COMPONENT VIEW
Bypass Cartridge:
The Bypass cartridge will come preinstalled from the factory. Please verify the three screws securing the Bypass cartridge are
ghtened, See “Bypass Cartridge” on page 64. NOTE: Pressure Relief Valve will need to be eld supplied with this model.
Commercial Gas Tankless Water Heater Use and Care Guide • 5
WATER HEATER BASICS
TYPICAL INSTALLATIONS
NOTE: If copper piping is used, then unions must be dielectric at inlet and outlet.
EXPANSION
TANK
Outlet Venting
Inlet Air
PRESSURE RELIEF VALVE
(DRAIN LINE NOT
SHOWN FOR CLARITY)
WATER SHUTOFF VALVE
WATER
SHUTOFF
VALVE
HOT
WATER
T
O FIXTURES
COLD
WATER
SUPPLY
DRIP LEG
GAS LINE
GAS
SHUTOFF VALVE
NOTE: Condensate Drain not
shown for clarity.
CWS
Drip Leg
HWS
Gas Line
Pressure Relief Valve
(Drain Line not
shown for clarity
)
Water Shutoff Valve
Gas
Shutoff Valve
Water
Shutoff
Valve
Check Valve
Return Line
NOTE: Condensate Drain not shown for clarity.
Expansion
Tank
Dedicated Return Line
WATER
SHUTOFF
VALVE
Water
Shutoff
Valve
Water Shutoff Valve
BYPASS
CARTRIDGE
PRODUCT
PRESERVER
EXPANSION
TANK
BYPASS
CARTRIDGE
COLD
WATER
SUPPLY
CHECK
VALVE
HOT WATER TO FIXTURES
GAS
EXPANSION
TANK
X3
CARTRIDGE
COLD
WATER
SUPPLY
CHECK
VALVE
HOT
WATER TO FIXTURES
GAS
Typical Installation with Bypass Cartridge
Typical Installation with Bypass Cartridge and
Product Preserver
Typical Installation with X3 Cartridge
6 • Commercial Gas Tankless Water Heater Use and Care Guide
WATER HEATER BASICS
DIMENSIONS
5.09 in
12.92 cm
6.70 in
17.00 cm
C
L
Wall
Water heater wall
mount contact point.
33.80 in
85.88 cm
3.73 in
9.47 cm
16.54 in
42.00 cm
16.12 in
40.96 cm
8.31in
21.12 cm
5.08 in
12.90 cm
3.22 in
8.22 cm
6.58 in
16.72 cm
Wall Studs
Dry Wall
26.70 in
67.82 cm
Note: If oponal X3 cartridge installed - top of ue to base of 41.8 inches (106.2cm)
Commercial Gas Tankless Water Heater Use and Care Guide • 7
WATER HEATER BASICS
Table 1: Supply Connecons
Item DESCRIPTION MEASUREMENT CONNECTION SIZE
1 HOT OUTLET 9.00 in/22.86 cm x 2.47 in/6.27 cm 3/4 in MNPT
2 GAS INLET 6.90 in/17.52 cm x 5.45 in/13.84 cm 1/2 in MNPT
3 CONDENSATE 3.20 in/8.07 cm x 2.30 in/5.84 cm 1/2 in MNPT
4 COLD INLET 4.80 in/12.20 cm x 3.46 in/8.79 cm 3/4 in MNPT
WALL
9.00 in
22.86 cm
6.90 in
17.52 cm
3.20 in
8.07 cm
2.47 in
6.27 cm
5.45 in
13.84 cm
2.30 in
5.84 cm
3.46 in
8.79 cm
4.80 in
12.20 cm
1
2
3
4
4
1
2
3
SUPPLY CONNECTIONS
8 • Commercial Gas Tankless Water Heater Use and Care Guide
Table 2: Specicaons
Model CTH-199M
Natural Gas/Propane Input
(Minimum Operating Range)
BTU/h 9,000
Natural Gas/Propane Input
(Maximum Operating Range)
BTU/h 199,000
Gas Connection 1/2 in MNPT
Water Connections 3/4 in NPT
Water Pressure* psi (MPa) 15 - 150 (0.1 - 1)
Water Flow Rate gpm (Lpm) 0.26 - 10.5 (1.0 - 39.7), Activation min: 0.4 (1.5)
Natural gas
Inlet Pressure
in W.C. (kPa)
Min 3.5 (0.87)
Max. 10.5 (2.62)
Propane
Inlet Pressure
in W.C. (kPa)
Min 8.0 (1.99)
Max. 13.0 (3.24)
Weight lbs (kg) 102 (46.2)
Dimensions
(including By-Pass Cartridge)
inch W 16.54 x H 33.80 x D 16.12
cm W 42.00 x H 85.55 x D 40.96
Ignition Electronic Ignition
Electric
Supply 120 V, 60 Hz, <2 A
*40 psi or above is recommended for maximum flow.
**Water Heater Category - Does not apply to Outdoor or Direct Vent Installations.
Category IV - a water heater that operates with a positive vent static pressure and with a vent gas temperature that may cause
excessive condensate production in the vent.
NOTE:
• Check the rating plate to ensure that this product matches your specifications.
• The manufacturer reserves the right to discontinue, or change at any time, specifications or designs without
notice and without incurring obligation.
WATER HEATER BASICS
SPECIFICATIONS
Commercial 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 data 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.
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 • Commercial 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! Read the
water heater’s data
plate to determine the type of gas
required. 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 water
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 Propane or Natural Gas that
meets all 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
manufacturer 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 Regular
Maintenance secon of this manual.
An explosion could occur if the
Pressure Relief Valve or discharge
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 data plate. The
minimum supply pressure is for the
purpose of input adjustment. L.P.
gas supply pressure must not exceed
13” water column. Have a qualied
person (licensed plumber, gas
company personnel, or authorized
service technician) check for proper
L.P. gas pressure. L.P. gas pressures
exceeding 13” water column 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
(temperature liming valves) at
each point-of-use. These valves
automacally mix hot and cold
water to limit the temperature
at the tap. Mixing valves are
available at your local plumbing
supplier. Follow the manufacturer’s
instrucons for installaon 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
(50°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: Burn/Scald 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 “Adjusng the Temperature”
secon in this manual.
• 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
Commercial 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
building, install Thermostac Mixing
Valves at each point-of-use.
If anyone in your building 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.
Properly adjusted Thermostac Mixing
Valves installed at each point-of-use
allow you to set the temperature to a
higher seng without increasing the
risk of 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.
• Keep the water heater from
becoming wet. Immediately shut
o the water heater and have it
inspected by a qualied person if
you nd that the wiring, gas valve
or user interface have been exposed
to water in any way (e.g., leaks from
plumbing, leaks from the water
heater itself can damage property
and could cause a re risk). If the
water heater is subjected to ood
condions or the gas valve or user
interface has been submerged in
water, the enre water heater 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.
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.
When the installaon is complete,
check the vent’s dra using the
instrucons on page 21.
• Do not install this water heater in
a mobile home or manufactured
housing.
• Failure to follow these instrucons
can result in serious injury or death
from carbon monoxide poisoning
WARNING! To reduce the risk of
carbon monoxide poisoning, install
a fuel gas and carbon monoxide
detector if the water heater is
installed in a bathroom, bedroom,
or any occupied room normally
kept closed. Install and maintain
the detector in accordance with the
manufacturer’s instrucons and local
codes
12 • Commercial 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
property 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.
• DO NOT install in a manufactured
home (mobile 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 U.S. or
the current edion of CSA C22.1
Canadian Electrical Code Part 1 in
Canada.
These are 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 be void. 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/provincial authories may have
similar requirements or other codes
applicable to the installaon of this
water heater.
3
Before you start, 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
ecient operaon. This manual
must be followed exactly. Read the
enre manual before installaon
and review the Safety Guidelines”
Secon.
• 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 the xtures,
if the plumbing system allows for it.
The water heater should be the rst
appliance to access the water line
aer ulies 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 servicing.
Install the unit so that it can be con-
nected or removed easily. Refer to
the "Unit clearances" secon page
17 for proper clearances.
• For outdoor installaons, locate the
water heater in an open , unroofed
area. Maintain 3 in. (76 mm) min-
imum 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 installation section for further
information.
GETTING STARTED
Commercial Gas Tankless Water Heater Use and Care Guide • 13
GETTING STARTED
• Failure to observe these warnings
could result in severe personal injury,
death, and/or property damage.
Venng/Combuson:
• Do not install the heater where water,
debris or ammable vapors may get
into the ue terminal. This may cause
damage to the heater and void the
warranty.
• Do not locate your heater in a pit or
locaon where gas and water can
accumulate.
• Do not install the exhaust vent for
indoor and outdoor models within
3 (914 mm) of an overhang.
• Do not install the unit where the ex-
haust vent is poinng into any open-
ing 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.
• Vent terminaon must be at least
2 (610 mm) away from both
the inside and outside corners for
outdoor installaon and direct-vent
installaon.
Outside
corner
Inside
corner
3
min.
2
min.
2
min.
Overhang
Figure 1 - Sidewall clearances
• Do not install next to a dryer or any
source of airborne debris that can be
trapped inside the combuson cham-
ber, unless the system is direct-vent-
ed. 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: 1 � (30 cm) min.
Canada: 3 � (91 cm) min.
USA: 1 � (30 cm) above grade and
above an�cipated snow level
Canada: 1 � (30 cm) above grade
An�cipated snow level
Figure 2 - Minimum Vent Clearances (Indoor)
US 4 (122 cm) min.
US 4 (122 cm) min. US 4 (122 cm) min.
Figure 3 - Minimum Vent Clearances (Outdoor Venng)
14 • Commercial Gas Tankless Water Heater Use and Care Guide
GETTING STARTED
4
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 building.
• Thread sealant tape or pipe joint
compound approved for potable
water.
• Pipe dope approved for gas
connecons or gas tape.
• For buildings 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
dishwashing soap mixed with water
(1 part soap to 15 parts water) or
children’s soap bubbles and a small,
so-bristled 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
Included Items
Table 4: Items Included with your Water Heater
Item Descripon
Manual Installaon Instrucons and Use & Care Guide.
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 23.
• 3/16 in x 3/8 in Vent Screw (x2)
Cascading Cable
Cascading Cable for electronically connecng tankless water heaters in
series for greater output.
• P/N 100377343
2 in Bird Screens
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.
Commercial Gas Tankless Water Heater Use and Care Guide • 15
Available Accessories
Table 5: Accessories available for your Water Heater
Item Descripon
Wi-Fi Module Kit
Wi-Fi Module for electronically connecng tankless water heaters to the
Internet and adapter to connect to the water heater.
• P/N 100371922
Remote
Temperature
Controller
Remote Temperature Controller with 10 (3 m) cable.
• P/N 100402144
Communicaon
Cables
Communicaon Cable Extensions for Remote Temperature Controller, Wi-
Fi Module, or Remote Recirculaon Kit.
• P/N 100377341 for 10 (3 m)
• P/N 100377342 for 32 (10 m)
Bypass Cartridge
Freeze Protecon
• Bypass Freeze Protecon can add an extra layer of freeze protecon to
external cartridge. Cartridge not protected by heater’s internal freeze
protecon.
P/N 100371918 for Bypass 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 100374697
Non-Return Vent
Adapter Kit
Non-Return Valve
4in. PVC Adapter
2in. to 3in. Increaser
Non-Return Vent Adapter Kit (For Common Vent Installaons only)
• P/N 100402142.
Neutralizer
Assembly Kit
Neutralizer Assembly neutralizes the condensate (acidic water) that forms
in the 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
GETTING STARTEDGETTING STARTED
16 • Commercial Gas Tankless Water Heater Use and Care Guide
Outdoor Vent Cap
Kit
Outdoor Installaon Kit containing the outdoor vent cap and User Inter-
face overlay.
• P/N 100369060
Crossover Valve Kit
Crossover Valve for recirculaon systems without a dedicated return line.
The kit includes a lead free Stainless/Brass Crossover Valve, Brass Tees
and 2 . Flex Hose.
• P/N 100327167
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
X3® Cartridge
Adds an addional layer of scale prevenon to the heater in extreme hard
water condions. Suitable for use in commercial applicaons as long as
the return water temperature does not exceed 120°F. See Table 16 on
page 42.
• P/N 100368986
X3 Cartridge®
Freeze Protecon
X3 Cartridge Freeze Protecon can add an extra layer of freeze protecon
to external cartridge. (NOTICE: cartridge not protected by heaters internal
freeze protecon)
• P/N 100325654 for X3 Cartridge Models
Product
Preserver®
Cartridge
Can be installed on the cold water line upstream of the tankless heater to
add an addional layer of scale prevenon.
• P/N 100291509 for PP-AS20 An-Scale System
• P/N 100291510 for PP-AS20R Replacement Cartridge
Bypass
Cartridge Screws
(x1)
(x2)
Screws to secure the Bypass Cartridge
• M4-12 mm (1x)
• M4-25 mm (2x)
GETTING STARTED
Commercial Gas Tankless Water Heater Use and Care Guide • 17
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
lines, 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 secon.
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
does not cover damage caused due
to freezing. See ”Freeze Protecon
System” on page 60.
Combuson air supply
The water heater requires fresh
combuson air and should be free of
corrosive elements and ammable
vapors. Direct venng installaon is
required when corrosive elements and
ammable vapors are present in the
room air.
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.
Indoor
Top: 12 in (305 mm) - Standard Venting
30 in (762 mm) - Common Venting
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)
Figure 4 - Indoor Clearances
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)
Overhang:
36 in (914 mm)
Figure 5 - Outdoor Clearances
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 6. DO
NOT secure to the 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 6 - Wall bracket installaon.
1. Hang the water heater on the wall
bracket. See Figure 7.
Wall
Bracket
Figure 7 - Mounng the water heater.
2. Secure the water heater rmly
fastening appropriate screws
into the upper bracket/boom
brackets of the water heater and
wall. NOTICE: these screws are
not provided.
Secure with screws.
Secure with screws.
Figure 8 - Use mounng screws.
INSTALLATION
18 • Commercial Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Combuson Air 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’re 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’ data 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 outdoor air is
recommended for all installaons.
Even if the water heater is installed
in a large, open room inside the
building, outdoor air is usually needed
because modern buildings 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.
Commercial 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 buildings 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. 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
building (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 % (percentage)
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-sec-
onal area as free area of the
opening.
• Rectangular ducts must have a
minimum dimension of no less than
three inches.
• All screens must have mesh ¼ in 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
To conrm that your installaon has
enough combuson air.
20 • Commercial Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Combuson Air Supply Opons
Exhaust
Intake
Wall
Roof
Exhaust must slope
upwards 1/4” per foot
Figure 9 - Direct Vent Vercal Installaon
Exhaust
Intake
Wall
Roof
Exhaust must slope
upwards 1/4” per foot
Figure 10 - Direct Vent Vercal/Horizontal
Installaon
Intake
Exhaust must slope
upwards 1/4” per foot
Exhaust
Wall
Roof
Figure 11 - Direct Vent Horizontal Installaon
Table 6:
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 in
2
(6.5 cm
2
) per 4,000 Btu/hr
Vercal ducts 1 in
2
(6.5 cm
2
) per 4,000 Btu/hr
Horizontal ducts 1 in
2
(6.5 cm
2
) per 2,000 Btu/hr
Single Opening 1 in
2
(6.5 cm
2
) per 3,000 Btu/hr
Two permanent openings
to another room**
1 in
2
(6.5 cm
2
) per 1,000 Btu/hr
Opening: 100 in
2
(645 cm
2
) Min
Minimum dimension of air openings: no less than 3 in (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, refer to the current edion of B149.1 Natural gas and propane installaon code.
Exhaust
Intake
Wall
Roof
Figure 12 - Indirect Vent Vercal Installaon
Exhaust
Intake
Wall
Roof
Figure 13 - Indirect Vent Horizontal Installaon
Commercial 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.
This vent system must be installed 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, this 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 (ABS, PVC, CPVC, or
Polypropylene Vent) Secon on page
23. Vent installaons in Canada
which ulize plasc vent systems must
use venng that is cered to ULC
S636.
Venng may not intermingle with
other manufactured material types,
other than approved adapters.
General rules for venng water
heaters:
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 from
the air ducted to the unit from the
outside.
• Follow the vent pipe manufacturer’s
installaon instrucons when install-
ing 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 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.
• For single venng installaons use
2 inch or 3 inch vent piping. For
common venng 4 inch vent piping
must be used.
• 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 rain water 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 in
(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
monoxide 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.
Improper installaon will void
product warranty.
Do not use Category I or Category
II venng systems with this water
heater.
If exisng venng and vent
terminaons are used, they MUST be
cleared of ALL restricons for proper
operaon, such as a restricter plate.
Read the “Installing Vent Pipe” secon
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 • Commercial Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Table 7: 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
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
*NOTE: This product is set to use PVC as the default vent pipe material. If the return water temperature for the applicaon is higher than 140°F (60°C) to
circulate back to the water heater, C08 must be set to ‘1’. Otherwise, the water heater will control maintain the exhaust and DHW temperatures below
149°F (65°C) and 140°F (60°C) respecvely. Note When C08 is set to ‘1’ (factory default is ‘0’), CPVC, PP, or SS vent must be used for the exhaust pipe.
Table 8: Vent Pipe Lengths
No. of
Elbows
Max. Vercal or Horizontal (Total) Vent Length
2 in venng 3 in venng
0 75 (22.9 m) 150 (45.7 m)
1 70 (21.3 m) 145 (44.2 m)
2 65 (19.8 m) 140 (42.7 m)
3 60 (18.3 m) 135 (41.1 m)
4 55 (16.8 m) 130 (39.6 m)
5 50 (15.2 m) 125 (38.1 m)
Excludes vent terminators, terminaon elbows, or rain caps.
For details on the vent connecon, refer to “Installing the Vent Pipe” on page 23.
For each 90 degree elbow added, deduct 5 . 45 degree elbows count as 2.5 feet.
Installing the Vent Pipe
WARNING! Improper installaon
can cause nausea or asphyxiaon,
severe injury or death from carbon
monoxide and ue gases poisoning.
Improper installaon will void
product warranty
• When inserng the pipe into the
exhaust/intake port, make sure
that the pipe end is cut straight and
posioned properly under the o-ring
to seal the connecon rmly.
• Improper venng of this appliance
can result in excessive levels of
carbon monoxide which can result in
severe personal injury or death.
Vent Piping
1
For single pipe venting insert
2 in diameter straight pipe
fully into the exhaust/intake
connection ports until fully seated
(See Figure 14). The pipes will insert
at a minimum of 1.5 inches.
NOTICE: For Common Venng
installaons see “Common Venng”
on page 28.
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 can cause carbon monoxide
poisoning or death.
NOTICE: For 3 in Venng, install
a 2 in x 3 in increaser to convert
to 3 in venng. For low clearance
installaons, a 2 in long sweep elbow
may be used. Then 12 in max length
straight pipe may be used to t a 2 in
x 3 in increaser.
Air Intake for Power Vent Installs:
Insert the male end of a 2 in long
sweep street elbow into the heater’s
air intake port.
2
Use a screwdriver to tighten
the clamp. (See Figure 14)
3
Use the supplied self-tapping
screws to secure the venting
to the intake and exhaust
ports as shown in the image on the
right. (See Figure 14)
Pipe end
not flush
with base.
Pipe end
is flush
with base.
Not a
90° edge
Exhaust Vent
Pipe
90° edge
Exhaust Vent
Pipe
Clamp
Self-Tapping Screw
Direct Vent (DV)
3 in Pipe
2 in to 3 in
Adapter
2 in Pipe
2 in Pipe
Exhaust Port
Intake
Port
Intake Port
Exhaust
Port
Figure 14 - Vent Pipe Installaon
Exhaust Vent for
Indoor Installaon
ABS, PVC, CPVC or
polypropylene vent
This model can be vented with
ABS, PVC, CPVC, or polypropylene
(temperature rated up to 149°F).
In Canada, plasc venng must be
cered to ULC S636.
• The maximum length of exhaust
venng or intake piping shall not
exceed the lengths listed in Table 8.
• Do not use more than ve elbows in
a vent system. For every 90 degree
elbow added, deduct ve feet and
45 degree elbows count as 2.5 . If
an elbow(s) is used in the vent sys-
tem, deduct each equivalent length
from the Max. vent length to decide
the total vent length.
• When the horizontal vent run
exceeds 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 in (6 mm) upwards for every 12
in (305 mm) toward the termina-
on or according to local and state
codes, or in the absence of local or
state/provincial codes, the current
edion of the ANSI Z223.1/NFPA 54,
Naonal Fuel Gas Code or B149.1,
Natural gas and propane installaon
code.
• Do not use ght 90° elbows.
Standard and long sweep elbows are
acceptable. See Figure 15.
Not Recommeded
90° Vent
Elbow
Recommended
90° Sweep
Elbow
90° Long
Sweep
Elbow
Figure 15 - Correct/Incorrect Elbows
Commercial Gas Tankless Water Heater Use and Care Guide • 23
INSTALLATION
24 • Commercial Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Direct Vent Horizontal Installaon Examples
Hanger
Direct Vent Vercal Installaon Examples
Fire Stop
Roof
Typical Venng Conguraons:
The following are typical single venng conguraons examples.
Figure 16 - Vent Conguraon Examples for Direct Vent
Commercial Gas Tankless Water Heater Use and Care Guide • 25
INSTALLATION
Table 9: - Vent Terminaons
LOW PROFILE TERMINATION
If used in vercal
posion, the
exhaust port must
be placed in the
upper side.
Vent Pipe Size PVC Kit Number IPEX PVC Part Number
IPEX System 1738®
PVC Part Number
2 in 100187903 196984 397984
3 in 100187887 196985 397985
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
2 in 100112869 196005 397005 197040
3 in 100112163 196006 397006 197006
POLYPROPYLENE CONCENTRIC TERMINATION
Vent Pipe Size Centrotherm Part Number
2 in ISLPT0202
3 in ISLPT0303
26 • Commercial Gas Tankless Water Heater Use and Care Guide
INSTALLATION
POLYPROPYLENE TERMINATION TEE
Vent Pipe Size Centrotherm Part Number
2 in ISTT0220
3 in ISTT0320
POLYPROPYLENE RADIUS ELBOWS
Vent Pipe Size Centrotherm Part Number
2 in 45° EXHAUST ELBOW ISELS0245UV
3 in 45° EXHAUST ELBOW ISELS0345UV
2 in 87° INLET ELBOW ISELS0287UV
3 in 87° INLET ELBOW ISELS0387UV
POLYPROPYLENE CONCENTRIC WALL TERMINATION
Vent Pipe Size Centrotherm Part Number
2 in ICWT242*
3 in ICWT352*
*Consult the vent manufacturer for approved concentric / twin pipe adaptors
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
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 ft (30 cm) 1 ft (30 cm)
B Clearance to window or door that may be opened 3 ft (91 cm)
1 ft
(30 cm)
4 ft (1.2 m) below or to side
of opening; 1 ft (30 cm)
above opening
C Clearance to permanently closed window 0 0 0
D
Vertical clearance to ventilated soffit located above
the vent terminator within a horizontal distance of 2
feet (61cm) from the center line of the termination
3 ft (91 cm) 3 ft (91 cm) 3 ft (91 cm)
E Clearance to unventilated soffit 3 ft (91 cm) 3 ft (91 cm) 3 ft (91 cm)
F Clearance to outside corner 2 ft (61 cm) 2 ft (61 cm) 2 ft (61 cm)
G Clearance to inside corner 2 ft (61 cm) 2 ft (61 cm) 2 ft (61 cm)
H
Clearance to each side of center line extended above
meter/regulator assembly
3 ft (91 cm) * *
I Clearance to service regulator vent outlet
Above a regulator within 3 ft (91 cm)
horizontally of the vertical center
line of the regulator vent outlet to a
maximum vertical distance of 15 ft (4.5
m)
* *
J
Clearance to non-mechanical air supply inlet to
a building or the combustion air inlet to any other
appliance.
3 ft (91 cm)
1 ft
(30 cm)
4 ft (1.2 m) below or to side
of opening; 1 ft (30 cm)
above opening
K Clearance to mechanical air supply inlet 6 ft (183 cm)
3 ft (91 cm) above if within
10 ft (3 m) horizontally.
L
Clearance above paved sidewalk or paved driveway
located on public property
7 ft (213 cm)**
7 ft
(213 cm)
7 ft (213 cm)
M Clearance under veranda, porch deck, or balcony 1 ft (30 cm)***
1 ft
(30 cm)***
1 ft (30 cm)***
*Clearance in accordance with local installation 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.
***Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
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 dam-
age; 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 Installation Code
2) In accordance with the current ANSI Z223.1/NFPA 54, National Fuel Gas Code
Commercial Gas Tankless Water Heater Use and Care Guide • 27
INSTALLATION
28 • Commercial Gas Tankless Water Heater Use and Care Guide
Common 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 Indoor model can be vented to-
gether using the same exhaust and
intake venng in a common venng
conguraon. Direct venng must
be used in this conguraon. DO
NOT use indirect venng.
• The use of venng materials ap-
proved for Category III/IV appli-
ances is recommended whenever
possible. However, the Indoor mod-
el 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 (ABS,
PVC, CPVC, or Polypropylene Vent)
Secon on page 23. Vent installa-
ons in Canada which ulize plasc
vent systems must use venng that
is cered to ULC S636.
• Venng may not intermingle with
other manufactured material types,
other than approved adapters.
• A non-return valve (100402144)
must be used for each water heater
that is part of the common vent
system. See”Non-Return Vent
Adapter” on page 32.
• ANSI Z223.1/NFPA 54 and/or
B149.1, Natural Gas and Propane
Installaon Code (Current Edions),
local codes, and the venng manu-
facturer’s instrucons.
• For common-venng pieces and
components, the manufacturer rec-
ommends Centrotherm’s vent line.
Common vented unit must be
connected using the Cascading/Easy
Link cable. To casacade units the
follow parameters must be set C13
and C14 in conguraon mode (C
Mode), see page 56.
Set C19 to 1 see page 56.
The following gures are examples of
typical common venng installaon
opons.
To calculate the maximum vent
length use the following instrucons.
INSTALLATION
Figure 17 - Typical Common Vented Installaon
Commercial Gas Tankless Water Heater Use and Care Guide • 29
Table 10: - Common Vent Fings (Tees, Elbows, and Terminaons)
Descripon Terminaon Horizontal Vercal
Equivalent
Lengths ()
Tee YES YES 8
90° Elbow YES YES 8
45° Elbow YES YES 5
Table 11: Allowable Maximum Vent Length (AMVL)
Main Vent Header Diameter
4" 6" 8" 10"
No. of Tankless Heater
Units
Maximum
BTU/Hr*
Minimum BTU/HR
with cascading
Allowable Maximum Vent Length (AMVL)
for Common Vented units (Feet)
2 398000 9,000 105 150 X X
3 597000 9,000 80 150 X X
4 796000 9,000 65 150 X X
5 995000 9,000 X 140 X X
6 1194000 9,000 X 125 150 X
7 1393000 9,000 X 105 120 X
8 1592000 9,000 X 85 120 150
9 1791000 9,000 X 70 95 135
10 1990000 9,000 X 50 80 120
11 2189000 9,000 X X X 105
12 2388000 9,000 X X X 90
*The common vented unit must be connected using Cascade/Easy Link cable. Refer to parameter C13 and C14 to cascade the
mulple units, see page 56.
*Set C19=1, see page 56.
* Do not common vent dierent types of tankless water heaters.
INSTALLATION
30 • Commercial Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Width (W)
Height (H)
Vent Pipe Diameter (D)
1
2
1
2
Tee: Elbow Equvivalent Vent length (EEVL)
90° Elbow: Elbow Equvivalent Vent length (EEVL)
45° Termination: Termination Equvivalent Vent length (TEVL)
3
3
Width (W) - 10ft
Height (H) - 3ft
Vent Pipe Diameter (D) - 4in
1
2
1
2
Tee: Elbow Equvivalent Vent length (EEVL) - 8ft
90° Elbow: Elbow Equvivalent Vent length (EEVL) - 8ft
45° Termination: Termination Equvivalent Vent length
(TEVL) - 5ft
3
3
EXAMPLE:
BTU Rating for each Unit in Cascade - 199,000 per unit.
Figure 18 - Maximum Allowable Vent Length
Commercial Gas Tankless Water Heater Use and Care Guide • 31
INSTALLATION
Maximum Vent Length Formula
Calculang the Maximum Vent Length Formula requires the summaon of 3 component variables then comparing them to
the values in Table 11. The calculated vent length must be under the maximum amount in the table. Use the steps below to
make the calculaons and record the values in the following table.
1. Calculate and record the Straight Vent Length (SVL) = Width (W) + Height (H)
2. Calculate and record the Elbow Equivalent Vent Length (EEVL) = Sum of elbow equivalent lengths in vent system. (See
Table 10 for component lengths)
3. Record the Terminaon Equivalent Vent Length (TEVL) = Terminaon equivalent length in vent system. (See Table 10 for
component lengths)
4. Record Vent Pipe Diameter (VPD) = Diameter of Vent Piping.
5. Record the number of units in the Cascade system.
6. Calculate and record the total BTU/H by adding the BTU rang of all heaters in the Cascade system.
7. Compare the informaon in the table below with Table 11 to see if the conguraon is within the allowable length.
Straight Value Length (SVL) (W) 10 + (H) 3 = 13 (SVL)
Elbow Equivalent Vent Length (EEVL)
Tee 8 (EELV)
90° Elbow 8 (EELV)
Sum of EELV 16 (EELV)
Terminaon Equivalent Vent Length (TEVL)* 90° Elbow 5 (TELV)
Calculated Maximum Vent Length (SVL)+(EEVL)+(TEVL)= 34
Vent Pipe Diameter 4in
Number of Units in Cascade System 3
Sum the BTU rang of all units in the Cascade System 199,000 x 3 597,000
Allowable maximum vent length (AMVL) is 80 for 3-unit conguraon with a 4in header diameter as per Table 11. The
calculated maximum vent length of 34 is within the allowed limit.
Table 11: Allowable Maximum Vent Length (AMVL)
Main Vent Header Diameter
4" 6" 8" 10"
No. of Tankless Heater
Units
Maximum
BTU/Hr*
Minimum BTU/HR
with cascading
Allowable Maximum Vent Length (AMVL)
for Common Vented units (Feet)
3 597000 9,000 80 150 X X
*If using a concentric vent, replace the (TELV) with equivalent length () for the concentric vent.
32 • Commercial Gas Tankless Water Heater Use and Care Guide
Exhaust
Intake
Wall
Non-Return
Valve
Condensate
Drain
Roof
Exhaust must slope upwards 1/4” per foot
Exhaust
Intake
W
all
Condensate Drain
Roof
Exhaust must slope upwards 1/4” per foot
Non-Return
Valve
Figure 19 - Vercal Combuson Air and Venng
Exhaust
Intake
Wall
Non-Return
Valve
Condensate
Drain
Roof
Exhaust must slope upwards 1/4” per foot
Exhaust
Intake
W
all
Condensate Drain
Roof
Exhaust must slope upwards 1/4” per foot
Non-Return
Valve
Figure 20 - Horizontal Combuson Air and Vercal Venng
Exhaust
Intake
Wall
Non-Return
Valve
Condensate Drain
Roof
Exhaust must slope upwards 1/4” per foot
Figure 21 - Horizontal Combuson Air and Venng
Non-Return Vent Adapter
WARNING! Each common vented heater must have a Non-
Return Valve (NRV), p/n 100402144, installed in the heater’s
exhaust. See the instrucons packaged with the NRV for
proper installaon. The installer (licensed professional) is
responsible for the correct installaon of the Non-Return
Valve (NRV) and for compliance with all naonal, state/
provincial, and local codes.
• A Non-Return Valve must be installed for each water heater.
This prevents the escape of combuson gas through non-
operang appliances.
• For detailed instrucons on the common-venng system,
refer to the instrucons that are packaged with the vent parts
or web site.
Non-Return Valve
4in. PVC Adapter
2in. to 3in. Increaser
Figure 22 - NRV Part Kit
INSTALLATION
Commercial Gas Tankless Water Heater Use and Care Guide • 33
INSTALLATION
Clearances for Sidewall
Terminaons
WARNING! Improper installaon
can result in carbon monoxide
poisoning or death. Follow all local
and naonal codes in regards to
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) from an inside corner
An�cipated Snow level
Exhaust
Termina�on
2 �
(610 mm)
min.
1 �
(305 mm)
min.
1 �
(305 mm)
min.
Inside
corner
Figure 23 - Mulple Sidewall Terminaons
Mulple DV Sidewall
Terminaons
A direct vent (DV) terminaon must
be at least:
• 1 (305 mm) from other DV termi-
naons
• 2 (610 mm) from an inside corner
Inside
corner
Ancipated Snow level
2
(610 mm)
min.
1
(305 mm)
min.
1
(305 mm)
min.
Combined
intake and
exhaust
terminaon
Figure 24 - Mulple DV Sidewall Terminaons
Exhaust and/or direct vent 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.
Exhaust
termination
2 ft (610 mm)
min.
Figure 25 - Sidewall Terminaon Minimum
Distance to another Structure.
For direct vent sidewall terminaons that use two separate penetraons for the intake and exhaust, keep the terminaon
clearances shown in the diagrams below.
0.5 ft
(159 mm)
min.
Exhaust
Intake
0.5 ft
(159 mm) min.
1 ft (305 mm)
min.
Exhaust
Intake
0.5 ft
(159 mm)
min.
Exhaust
Intake
0.5 ft
(159 mm) min.
1 ft (305 mm)
min.
Intake
Exhaust
Figure 26 - Direct Vent Sidewall Terminaons
34 • Commercial Gas Tankless Water Heater Use and Care Guide
Clearances for Rooop
Terminaons
WARNING! Follow all local and
naonal codes in regards to 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 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
terminals:
• Intake terminals: 1 (305 mm)
spacing between each
• Exhaust terminals: 1 (305 mm)
spacing between each
• 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.
Typical PDV Installation
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
Follow all local and naonal codes in regards to proper terminaon clearances. In the absence
of such codes, the clearances below must be met. Local codes supersede these clearances.
Exhaust Vent
Air Intake
Figure 27 - Pitched roof with mulple vercal terminaons.
Commercial Gas Tankless Water Heater Use and Care Guide • 35
INSTALLATION
1 ft (305 mm) min.
Typical PDV Concentric Installation
1 ft (305 mm) min.
* Anticipated Snow
Level (ASL).
Exhaust Vent
3 ft (914 mm) min.
Anticipated Snow Level
ISO VIEW
FRONT
FRONT
FRONT
Follow all local and naonal codes in regards to proper terminaon clearances. In the absence
of such codes, the clearances below must be met. Local codes supersede these clearances.
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
Figure 28 - Pitched roof with mulple vercal concentric terminaons.
36 • Commercial Gas Tankless Water Heater Use and Care Guide
CHAPTER HEADERINSTALLATION
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 in regards to 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 29 - Flat roof with mulple vercal terminaons.
Commercial Gas Tankless Water Heater Use and Care Guide • 37
INSTALLATION
Exhaust Venng for
Outdoor Installaon
1
Turn o power and the gas
supply to the water heater.
Remove the four screws from
the top plate of the water heater as
shown in the gure below.
Screws
Figure 30 - Remove top plate screws.
2
Orient the outdoor vent cap
as shown in Figure 31.
Figure 31 - Outdoor Vent Cap secure with
screws.
3
Secure the Outdoor Vent Cap
to the water heater at each
corner with the screws
removed earlier. See Figure 31.
Figure 32 - Control Panel Cover Plate Install.
4
Aach the UIM overlay as
shown in Figure 322.
5
Remove the front cover and
remove the screw on the top
le holding the computer
board in place, press the locking tab
and pull the computer board towards
yourself to lower it on the hinge to
access the air inlet plate.
6
Locate the air inlet plate as
shown in Figure 333. 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 up. Secure
with the screws removed earlier.
INDOOR CONFIGURATION
OUTDOOR CONFIGURATION
Figure 33 - Air inlet plate orientaon opons
.
7
Connect the water heater to
power. See “Electrical
Connecons” on page 46.
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 46.
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
boom of heater. It protects plumbing
connecons to the heater while
improving the appearance of the
installaon.
For more informaon see “Available
Accessories” on page 15
38 • Commercial Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Gas Supply and Gas
Pipe Sizing
Gas Piping
WARNING! Read the water
heater’s data plate to determine
the type of gas required. 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 shown below. Excess gas
inlet pressure may cause serious
accidents.
• The water heater is set only for
Natural Gas at the factory.
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 supply line
pressure tesng has been complet-
ed to avoid any damage to the water
heater.
• The minimum and maximum inlet
gas pressures are:
Table 12: - Inlet Gas Type/Pressure
Natural Gas:
Min 3.5 in W.C. (0.87 kPa)
Max. 10.5 in W.C. (2.62 kPa)
Propane:
Min 8.0 in W.C. (1.99 kPa)
Max. 13.0 in W.C. (3.24 kPa)
Size the gas pipe appropriately to
supply the necessary volume of gas
pressure, and allowable pressure drop
required for the water heater using
gas piping manufacturer 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.
• 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 all other gas appliance(s)
served by the same gas line are in
full operaon.
• Inlet gas pressure must not exceed
the maximum values in Table 12; gas
pressure above the specied range
will cause dangerous operang con-
dions and damage to 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 is at least 3 (1 m) of
piping between the regulator outlet
and the water heater's inlet gas
connecon.
Gas Connecons
1
Use a 1/2 in union to connect
gas piping to the water
heater's 1/2 in male NPT
connection.
2
Install a readily accessible
manual shut-o valve in the
gas supply line as
recommended by the local ulity.
Know the locaon of this valve and
how to turn o the gas to this unit.
3
Install a Sediment Trap as
shown in .”TYPICAL
INSTALLATIONS” on page 5 The
Sediment Trap must be no less than
three inches long for the accumulaon
of dirt, foreign material, and water
droplets.
4
When the gas connections
are completed, it is necessary
to perform a gas leak test
either by applying soapy water to all
gas fittings and observing for bubbles
or by using a gas leak detection
device.
• The water heater and its
individual shuto 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 iso-
lated from the gas supply piping
system by closing its individual
manual shuto 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).
5
Always purge the gas line of
any debris and/or water
before connecng to the gas
inlet.
6
Install a ground joint union
between the gas control valve
and the manual gas shut-o
valve. This is to allow easy removal of
the gas control valve.
7
Turn the gas supply on and
check for leaks. Use a small,
so-bristled brush to apply a
hand dishwashing soap and water
mixture (1 part soap to 15 parts
water) or children’s soap bubbles to
all connecon points of the gas piping.
Saturate all the connecons and check
for gas leaks (which will appear as
small bubbles). If any leaks are
detected, ghten the appropriate
connecon(s) and re-check.
Natural Gas Supply Piping
Maximum delivery Capacity in Cubic
Feet of Gas per Hour (based on IPS
Commercial Gas Tankless Water Heater Use and Care Guide • 39
INSTALLATION
Pipe carrying Natural Gas with 0.60 Specic Gravity with a Pressure Drop of 0.5 in W.C.).
Based on Energy Content of 1,000 BTU/
3
: The water heater requires 199
3
/h for the CTH-199M.
The following tables are from ANSI Z223.1/NFPA 54. (Unit: Cubic feet per hour)
Table 13: Natural Gas Table
Pipe Size Length
Diameter
10 ft
(3.0 m)
20 ft
(6.1 m)
30 ft
(9.1 m)
40 ft
(12.2 m)
50 ft
(15.2 m)
60 ft
(18.3 m)
70 ft
(21.3 m)
80 ft
(24.4 m)
90 ft
(27.4 m)
100 ft
(30.5 m)
125 ft
(38.1 m)
150 ft
(45.7 m)
200 ft
(61.0 m)
1/2 in 172 118 95 81 72 65 60 56 52 50 44 40 34
3/4 in 360 247 199 170 151 137 126 117 110 104 92 83 71
1 in 678 466 374 320 284 257 237 220 207 195 173 157 134
1-1/4 in 1,390 957 768 657 583 528 486 452 424 400 355 322 275
1-1/2 in 2,090 1,430 1,150 985 873 791 728 677 635 600 532 482 412
2 in 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 (LP) supply piping
Maximum Capacity of Propane (LP) Based on 11 in W.C. supply pressure at a 0.5 in W.C. pressure drop. (Unit: kBTU per hour)
Table 14: Propane Gas Table
Pipe Size Length
Diameter
10 ft
(3.0 m)
20 ft
(6.1 m)
30 ft
(9.1 m)
40 ft
(12.2 m)
50 ft
(15.2 m)
60 ft
(18.3 m)
70 ft
(21.3 m)
80 ft
(24.4 m)
90 ft
(27.4 m)
100 ft
(30.5 m)
125 ft
(38.1 m)
150 ft
(45.7 m)
200 ft
(61.0 m)
1/2 in
268 184 148 126 112 101 93 87 82 77 68 62 53
3/4 in 567 393 315 267 237 217 196 185 173 162 146 132 112
1 in 1,071 732 590 504 448 409 378 346 322 307 275 252 213
1-1/4 in 2,205 1,496 1,212 1,039 913 834 771 724 677 630 567 511 440
1-1/2 in 3,307 2,299 1,858 1,559 1,417 1,275 1,181 1,086 1,023 976 866 787 675
2 in 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
Water heater
199,000 BTU/h
Dryer
35,000 BTU/h
Gas meter
Furnace
120,000 BTU/h
Range
65,000 BTU/h
A
B
C
10' (3 m)Length
1/2" Pipe size
15' (4.6 m)Length
1/2" Pipe size
15' (4.6 m)Length
1" Pipe size
10' (3 m)Length
3/4" Pipe size
10' (3 m )Length
1" Pipe size
5' (1.5 m) Length
1-1/4" Pipe size
10' (3 m)Length
1/2" Pipe size
5' (1.5 m)Length
1-1/4" Pipe size
Gas sizing example
(Natural Gas)
Based on Energy Content of 1,000 BTU/
3
:
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, look in the above gas chart to properly size the line.
For secons of the gas line supplying gas to more than one appliance (Ex: Point A to Point B), add up the cubic 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 requirements and
dividing by 1,000 yields a
3
/hr requirement of 220
3
of gas per hour. The farthest appliance is the range, which is 50 away
from the meter. Looking at the above chart, and under the column of 50 , Secon A to B needs to be 1 in in order to supply
220
3
.
INSTALLATION
Gas Conversion
Restricon
The water heater is set only for
natural gas at the factory. No eld gas
conversion is allowed.
WARNING! An improper eld
conversion could cause potenally
dangerous condions that may
cause an explosion or re resulng
in property damage, bodily injury or
both.
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!
NOTICE: Do not reverse the hot
outlet and 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 building. Use ngs
appropriate for the type of pipe
in your building (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 systems. 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 shuto valve must be
installed on the cold water inlet to
the water heater between the main
water supply line and the water
heater.
• Install Thermostac Mixing Valves
to regulate the temperature of the
water supplied to each point-of-use
(for example, kitchen sink, bath-
room sink, bath, shower). Install and
adjust the mixing valve according to
its manufacturer’s instrucons.
WARNING! Even if the water
heater’s thermostat is set to a
relavely low temperature, hot
water can scald. Install Thermostac
Mixing Valves at each point-of-use
to reduce the risk of scalding (see
Table 3).
BACKGROUND: A Thermostac Mix-
ing Valve, installed at each point-of-
use, mixes hot water from the water
heater with cold water to more
precisely regulate the temperature
of hot water supplied to xtures. If
you are not sure if your plumbing
system is equipped with properly
installed and adjusted Thermostac
Mixing Valves at each point where
hot water is used, contact a quali-
ed person.
• Water expands when heated, and
the increased volume of water
must have a place to go, or thermal
expansion will cause large increas-
es in water pressure (despite the
use of a Pressure Reducing Valve
in the home’s main water supply
line). The Safe Drinking Water Act
of 1974 requires the use of back-
ow preventers and check valves
to restrict water from your home
reentering the public water sys-
tem. Backow preventers are oen
installed in water meters and may
not be readily visible. As a result,
most all plumbing systems today are
now “closed,” and almost all homes
now need a Thermal Expansion Tank
Expansion tanks are pre-charged
with a minimum of 12 psi air charge.
The expansion tank’s air pressure
must be adjusted to match the inlet
pressure of your home but must not
be higher than 80 psi.
• Connect the cold water supply using
3/4 inch Naonal Pipe Thread “NPT”
to the ng marked COLD.
• For ease of removing the water
heater for service or replacement,
connect the water pipes with a
union. We recommend using a di-
electric-type union (available at your
local plumbing supplier). Dielectric
unions can help prevent corrosion
caused by ny electric currents
common in copper water pipes and
can help extend the life of the water
heater.
• 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.
• In addion, a manual shuto valve is
also recommended on the hot water
outlet.
• Double check to make sure the hot
and cold water pipes are connected
to the correct hot and cold water
ngs on the water heater.
• If needed, install (or adjust) the
building’s Pressure Reducing Valve.
• Before installing the water heater,
ush the water line to remove all
debris, and aer installaon is com-
plete, purge the air from the line.
Failure to do so may cause damage
to the heater.
• There is a wire mesh lter within
the cold inlet to trap debris from en-
tering your heater. This will need to
be cleaned periodically to maintain
opmum ow.
• 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.
• If water hammer is evident install
water hammer arrestors on the inlet
side.
• 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 building has copper water
pipes, you can solder the water pipe
connecons or use compression
ngs which don’t require soldering.
Compression ngs are easier to
40 • Commercial Gas Tankless Water Heater Use and Care Guide
INSTALLATION
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:
• Solder a short length of pipe (about
a foot or so) to a threaded adapter
using only 95/5 n anmony or
equivalent solder.
• Aach the threaded adapters to the
water heater’s connecons (using
thread sealant tape or pipe joint
compound). Connect the building’s
water pipes by soldering, keeping
the connecons at the water heater
cool with wet rags.
Recirculaon
External Pump
When installing an external
recirculaon pump, care must be
taken to properly size the pump
for the applicaon. Sizing must
be performed by the installing
contractor or engineer. The following
requirements need to be observed
when sizing:
• Size the recirculaon pump to ow
no less than 2 gpm (7.6 l/m) and no
more than 4 gpm (15.1 l/m) per ac-
vated heater. The manufacturer’s
suggested ow rate is 3 gpm (11.4
l/m). Refer to the water heater’s
pressure drop chart on its specica-
on sheet for losses at other ow
rates. Head loss at 3 gpm is approxi-
mately 16.9 . of head (7.3 psi) 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). NOTE: Running the
pump connuously will reduce the
warranty of the water heater.
• 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. Note that
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.
Below is a suggested piping
diagram. Check with local codes and
ordinances for addional installaon
requirements. Refer to the water
heater manufacturer’s website for
addional layouts.
Thermostac mixing valves may be
used with tankless water heaters.
Consult with the mixing valve
manufacturer for the appropriate
mixing valve for the applicaon. Refer
to the thermostac mixing valve
manufacturer for proper installaon
when recirculaon is in use.
To reduce the risk of scalding,
install Thermostac Mixing Valves
(temperature liming valves) at each
point of use.
X3
CARTRIDGE
COLD
WATER
SUPPLY
EXPANSION
TANK
CHECK
VALVE
HOT WATER TO FIXTURES
BUILDING RETURN
PUMP
TEMP. PROBE
GAS
SHUT OFF
VALVE
NOTE: X3 cartridge MUST have a return loop
temperature LESS than 120°F.
PRODUCT
PRESERVER
BYPASS
CARTRIDGE
COLD
WATER
SUPPLY
EXPANSION
TANK
CHECK
VALVE
HOT WATER TO FIXTURES
BUILDING RETURN
PUMP
TEMP. PROBE
GAS
SHUT OFF
VALVE
Figure 34 - Recirculaon Loop Typical Conguraons
Commercial Gas Tankless Water Heater Use and Care Guide • 41
42 • Commercial Gas Tankless Water Heater Use and Care Guide
INSTALLATION
Combinaon Potable
Water and Space
Heang
WARNING! This water heater
is suitable for combinaon water
(potable) heang & space heang,
and not suitable for space heang
applicaons only.
• This water heater shall not be
connected to any heang system
or component(s) previously used
with non-potable water where any
chemicals were added to the water
heang appliances.
• Toxic chemicals used in boiler treat-
ments such as alcohol, glycerol, and
glycol groups must not be intro-
duced into the water system.
• When the system requires water
for space heang at temperatures
higher than required for other uses,
thermostac mixing valves must be
installed at each point-of-use. Wa-
ter temperatures over 125°F (52°C)
can cause severe burns instantly or
death from scalding. Failure to ob-
serve these warnings could result in
severe personal injury or death.
Care must be taken by the installing
contractor or design engineer to
size the components of the system
appropriately for ow rate and
temperature. In addion to sizing
the water heater for the domesc
potable water, the installer must size
the water heater to provide the ow
rate required by the manufacturer
of the air handler. Refer to the air
handler manufacturer’s instrucons
and specicaon documents for this
ow rate. The pump, eld supplied
or provided by the air handler
manufacturer, must be able to provide
this minimum ow rate.
When sizing the pump, the installer
must take into account the pressure
drop of the following:
• Hydronic Air Handler. Refer to the
manufacturer for this informaon.
• Water Heater. Refer to the water
heater’s specicaon sheet for pres-
sure drop informaon. At 3 gpm, the
approximate head loss is 16.9 . of
head (7.3 psi).
• Water Tubing Size, Length, and
Material. Refer to the water tubing
manufacture for pressure drop
informaon as it diers from one
material to the next and at dierent
sizes. There may be addional
applicaon requirements by the
water tubing manufacturer.
• Fings: Refer to the ng
manufacturer for pressure drop
informaon.
Addional consideraons are:
• Installing an air eliminaon device
to remove air that may cause
cavitaon in the pump.
• A priority control device, such as a
ow switch, to priorize the domes-
c water system over the heang
system.
• Thermostac mixing valves at each
point-of-use. Refer to the mixing
valve manufacturer for proper selec-
on and installaon.
Figure 35 is a suggested piping
layout. The installer must properly
install the system per manufacturer’s
instrucons and local codes.
GAS
AIR HANDLER
TEMPERED HOT
WATER TO FIXTURE
EXPANSION
TANK
COLD
WATER
SUPPLYCHECK
VALVE
SHUT OFF
VALVE
PUMP
THERMOSTATIC MIXING
VALVE
CHECK
VALVE
NOTE: X3 cartridge MUST have a return loop
temperature LESS than 120°F.
Figure 35 - Air Handler/Recirculaon Loop Conguraons
Commercial Gas Tankless Water Heater Use and Care Guide • 43
INSTALLATION
Dual Purpose Water
Heang for the State of
Massachuses
• This secon applicable to
Massachuses (USA) installaons
only. Not applicable in Canada.
• Priority Control Devices such as a
ow switch, an Aquastat or other
electronic controller can be used to
priorize the domesc water system
over the heang system.
• Follow all local codes, or in the
absence of local codes, follow the
current edion of the Naonal Stan-
dard Code, ANSI Z21.10.3, CSA 4.3.
• The illustraon below is a concept
design only. The reference to
the 1/8-inch hole in the check
valve is only required in the State
of Massachuses. There are
a wide variety of variaons to
the applicaon of controls and
equipment presented. Designers
must add all the necessary safety
and auxiliary equipment to conform
to code requirements and design
pracce. For more details, contact
the manufacturer or local code
authority.
120 VAC
switch or
outlet
Hot water outlet
Check valve
Electronically controlled
every 6 hours for 60
seconds. Wire to
product approved pump
(used with air-handler)
Cold water supply
Discharge must
comply with local and
state codes. Cannot
be common vented
with other appliances
An approved temperature and pressure
water heater model used
Check valve will have
1/8-inch hole drilling
Atmospheric
vacuum
breaker
valve
Pressure
gauge
Apply correct thermal
expansion tank-size
Check valves
Cold water inlet
Gas inlet
Water
Drain
plug
Hot water
supply and
return to
System installed with reverse
Suggested but not required by
248 CMR
50’-0” maximum distance from
water heater to fan coil.
(Developed length) Not including
NSF-61 product
approved pump
must be installed below
the top of the water heater
as per manufacturer’s
Piping loop
between water
heater and fan
coil shall be in
compliance with
248 CMR
Tempered water to
meet temperature
requirements of 248 CMR
All water piping should be insulated
in accordance with 780 CMR
The recirculaon pump is to provide no less than 2 GPM (7.5 L/min) and no more than 4 GPM (15 L/min) through
each acvated unit in the system.
Ball
Valve
Isola�on
Valve
Unions
Figure 36 - Diagrammac Layout of Radiant Heang and Domesc Water Heater
INSTALLATION
Water Quality
The performance, eciency, and
service life of a tankless water heater
depends heavily on the quality of
the water supplied to the unit. For
safe, reliable, long-life operaon, the
tankless water heater should only be
connected to a potable water source
that meets drinking water standards.
Water should be free of corrosive
chemicals, aggressive cleaning agents,
or other contaminants that can cause
premature deterioraon of internal
components, reduce heat exchanger
eciency, and lead to avoidable
maintenance issues and premature
failure. Untreated or contaminated
water may result in damages not be
covered under warranty.
In regions with hard water,
addional treatment such as
soening, condioning, or ushing/
descaling may be required to
prevent scale accumulaon within
the heat exchanger. Excess mineral
content signicantly aects system
performance and will increase
maintenance frequency and should be
properly managed. Consult a qualied
technician familiar with water quality
in your area to formulate a plan for
roune maintenance.
Ensuring appropriate water quality
is a crical part of protecng the
equipment, maintaining warranty
compliance, and achieving long-term,
trouble-free operaon.
Table 15: Secondary Maximum
Contaminant Levels For Public
Water Systems
Contaminant Maximum Level
Total Hardness
Up to 200 mg/L
(12 gpg)
Aluminum Up to 0.2 mg/L
Chloride Up to 250 mg/L
Copper Up to 1.0 mg/L
Iron Up to 0.3 mg/L
Manganese Up to 0.05 mg/L
pH 6.5 to 8.5
Sulfate Up to 250 mg/L
Total Dissolved
Solids (TDS)
Up to 500 mg/L
Zinc Up to 5 mg/L
Source: EPA Part 143 - Naonal Secondary
Drinking Water Regulaons
44 • Commercial Gas Tankless Water Heater Use and Care Guide
Table 16: Water Hardness & Suggested Maintenance Matrix
Hardness
Classification
MG/L
Grains Per
Gallon
Water Treatment Method
Commercial Flushing
Maintenance Frequency
So 0 - 60 0 - 3.5
Water Soener or Product Preserver
(PP-AS20) Recommended
Once/Year
Moderately Hard 61 - 120 3.5 - 7.0
Water Soener or Product Preserver (PP-AS20) or X3 Scale Prevenon Cartridge*
Highly Recommended
Twice/Year**
Hard 121 - 180 7.0 - 10.5
Extremely Hard 181 - 250 10.5 - 14.5
Water Soener or Product Preserver (PP-AS20)or X3 Scale Prevenon Cartridge*
Required
*X3 Scale Prevenon cartridge (100368986) replaces the commercial CTH-199M Bypass Cartridge to add an addional layer
of scale prevenon to the heater in extreme hard water condions. The X3 Scale Prevenon cartridge is suitable for use in
commercial applicaons with or without recirculaon as long as the return water temperature does not exceed 120°F. Not
suitable for commercial recirc systems with dedicated return lines where returning water temperatures may exceed 120°F.
**Frequency of ushing maintenance may need to be increased dependent on a variety of factors including water treatment
methods employed, set point water temperature, water usage, and local water hardness. Consult a qualied professional
familiar with local water condions and commercial applicaons for guidance on maintenance scheduling to maintain opmal
performance.
INSTALLATION
Pressure Relief Valve
NOTICE: A Pressure Relief Valve is NOT
provided with the water heater and
must be eld supplied by the installer.
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.
6” (152.4 mm)
Maximum
Discharge Pipe
Figure 37 - Discharge Pipe
The water heater has a high-
temperature shuto switch built in
as a standard safety feature (called a
Hi-Limit switch) therefore a “pressure
only” relief valve is required.
• The discharge piping for the pres-
sure relief valve must be directed
so that the hot water cannot splash
outward and cause damage or per-
sonal injury.
• The pipe must also be able to with-
stand 210°F without distoron. Use
only copper or CPVC pipe approved
for discharge use. Do not use any
other type of pipe, such as PVC,
iron, exible plasc pipe, or any type
of hose.
• Aach the discharge tube to the
pressure relief valve and run the end
of the tube to within 6 in (152 mm)
from the oor for US installaons
and 12 in (305 mm) for Canadian in-
stallaons. This discharge tube must
allow free and complete drainage
without any restricons.
• In cold climates, terminate the
discharge pipe inside the building to
an adequate drain. Outside drains
could freeze and obstruct the drain
line — protect the discharge pipe
from freezing.
• If the pressure relief valve discharg-
es 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. Do not plug the pressure
relief valve.
The pressure relief valve must be
manually operated annually to
check for correct operaon. Before
operang the valve manually, check
that it will discharge in a place for
secure disposal.
• No valve must be placed between
the relief valve and the water heater.
• If another pressure relief valve is
used or needs to be replaced, it
must meet the following:
• The pressure relief valve must
conform to local codes.
• The discharge capacity must be
at least 199,000 BTU/h for the
CTH-199M model,
• The pressure relief valve needs
to be rated for a maximum of
150 psi (1 MPa).
Condensate Drain
• Follow all code requirements of the
local authority on condensate neu-
tralizers and whether or not they are
required for the installaon.
• Discharge condensate (acidic water)
in accordance with all local codes
and common safety pracces.
• Install minimum 1/2 in corrosion
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
atmospheric 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 eecvely
neutralized if the neutralizer
elements have been completely
consumed. If this happens,
condensate will remain acidic and
can possibly 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 manufacturer 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.
Commercial Gas Tankless Water Heater Use and Care Guide • 45
INSTALLATION
Electrical Connecons
WARNING! Working on an
energized circuit can result in severe
injury or death from electrical
shock.
1
The water heater must be
electrically grounded. Do
not attach the ground wire
to either the gas or the water
piping.
2
The water heater requires a
120 VAC, 60 Hz electrical
power supply that is
properly grounded.
• A proper disconnect (i.e. on/
o switch, power plug, etc.)
controlling the main power
to the water heater must be
provided for service reasons.
(Must comply with local
codes.)
• This water heater comes
equipped with a SJWT rated
cord which is weather resistant
and rated for outdoor use.
3
The water heater can be
hardwired or plugged into an
outlet with the correct voltage
listed above using the supplied power
cable already attached.
4
The use of a surge protector
is recommended in order to
protect the unit from power
surges.
Plug-in Connecon
1
The water heater should be
plugged into a 120VAC, 60
HZ ground electrical outlet.
Hard Wired Connecon
NOTE: Follow the steps below if the
power supply must be hardwired
to the water heater. Otherwise, you
may skip this section.
1
Remove and keep the
screws securing the front
cover, then remove it.
2
Remove and keep the screw
in the upper le corner of
the printed circuit board.
3
Depress the latch in the
upper right corner of the
printed circuit board and
lower it.
4
Locate the system power
cord using Figure 388. Cut
the wires at the locaon
shown in Figure 388.
Figure 38 - System power cord cut locaon.
5
Remove the screws securing
the power cord to the
boom of the water heater.
6
Remove the power cord
from the boom of the
water heater and install a
strain relief connector in the
opening.
7
Make the electrical
connecon to the water
heater. Follow all local
codes or in the absence of local
codes, with the Naonal Electrical
Codes: ANSI/NFPA 70 in the USA.
8
Verify all electrical
connections are secure.
9
Replace the front cover and
turn on power to the water
heater.
10
Follow the instructions in
the Getting Started section
of this manual.
46 • Commercial Gas Tankless Water Heater Use and Care Guide
Commercial Gas Tankless Water Heater Use and Care Guide • 47
INSTALLATION
Cascade System
The Cascade System allows up
to 12 heaters of the same input
to be linked in a Parent/Child
conguraon. Do not link heaters of
dierent input rates together.
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. Contact the
heater manufacturer for addional
informaon.
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 configured with the
Parent water heater as
either the first or last in the series of
water heaters connected to the cold
water supply. The Child units will
follow sequentially. See Figure 40.
2
Before proceeding,
disconnect electrical power
to all water heaters in the
Cascade configuration.
3
Remove the front cover and
keep the two screws from
the Parent and from each
Child water heater for re-installaon.
4
On the Parent water heater
lift the plastic clip locking
the control panel in place
and lower it down out of the way.
5
Remove and keep the clear
plasc shield material that
covers the Printed Circuit
Board (PCB) for re-installaon.
6
On the boom of the water
heater locate the rubber
access grommet. 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 39 - Boom of water heater -
Grommet.
7
Use Figure 40 as a reference
to locate the connection
point for the Parent
Cascade Unit. Use the single harness
end of the Cascade Linking Cable to
make the initial connection.
8
Follow steps 4-6 to route
the double harness end of
the Cascade Linking Cable
to the printed circuit board on the
first 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 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 40.
10
Once all connections are
made, the water heaters
must be assigned their
position in the system. Turn on the
power supply to all of the water
heaters, making sure there is no
water flow.
11
On the Parent water heater
simultaneously press and
hold the SETTING and UP
buons unl C00 appears. See Table
21 on page 56.
OPERATION
12
Press the UP arrow button to
reach the C13 option, then
press SETTING button to
enter that option.
NOTE: C13 defines the number of
Child water heaters that will be
connected to the parent unit.
Enter the number of Child water
heaters attached to the parent water
heater and press Settings 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
button again to return to normal
operation.
13
After the Parent water heater
is configured, the Child water
heaters must be configured.
Perform the following steps on each
Child water heater.
14
On each Child unit’s UIM,
press and hold both the
SETTING and UP buttons until
C00 appears.
15
Press the UP arrow button to
reach the C14 option, then
press the SETTING button to
enter that option.
NOTICE: C14 defines the number
assigned to each Child water heater
connected to the parent water heater.
16
Enter number 2 for the first
Child water heater and press
the SETTING button to load
the number to memory. Repeat this
step assigning a sequencial number at
each additional Child water heater.
17
Press and hold the SETTING
button again to return to
normal operation. NOTICE: A
maximum 31 Child water heaters can
be connected to a Cascade System of
32 total water heaters.
18
Verify all electrical
connections and conduit
connections are secure.
19
Follow the instructions in the
Getting Started section of
this manual.
48 • Commercial Gas Tankless Water Heater Use and Care Guide
Parent Unit
Child UnitChild Unit
Child Unit
CWS
HWS
Gas
Supply
Building Return
Cascade
Linking
Cable
Parent Unit
Child Unit
Single
Harness
End
Double
Harness
End
Figure 40 - Mul Unit Cascade Conguraon
Commercial Gas Tankless Water Heater Use and Care Guide • 49
Accessory Connecons
This system supports up to three
accessories connected in series.
NOTE: If mulple water heaters are
used in a Cascade conguraon, all
accessories must be connected in
series to the parent unit.
Follow the accessory kit instrucons
to access the control board.
Each accessory has a both a ve pin
female connector and a secon of
cable with a ve pin male connector
on the end. See Figure 41 The male
connector connects to the control
board or to the next accessory in the
series. The ve pin female connector
allows another accessory to connect
and create a series. Reference the
gure below when creang a series
of accessories. If the length of the
accessories 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 communicaon cable to the
ve pin female connector on the
accessory. The maximum wire length
from the water heater (parent in
a Cascade System) to the furthest
accessory is 100 (30 m).
OPERATION
Wi-Fi Module
Remote
Controller
Outdoor Wall
Indoor Wall
Accessories can be installed
indiviudually or in a series
conguration as shown above.
5-Pin Accessory
Connector
Accessory
5-Pin Female
Accessory
5-Pin Male
Figure 41 - Accessories installed in series
OPERATION
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
supplier, call the re department.
• Failure to observe these warnings
could lead to re or an explosion,
resulng in severe injury or death.
D Check the GAS and WATER CON-
NECTIONS for leaks before ring
unit for the rst me.
D 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 qualied service technician.
Forced repair may result in a re
or explosion due to gas leaks.
D Be sure to check for the pres-
ence of leaking gas toward the
boom of the unit because
some gases are heavier than air
and may sele towards the oor.
D Check the GAS PRESSURE. Refer
to “Gas Supply and Gas Pipe
Sizing” on page 38.
D Check for PROPER VENTING and
COMBUSTIBLE AIR to the water
heater.
D Purge the GAS and WATER LINES
to remove any air pockets.
D Do not use this appliance if
any part has been under water.
Immediately contact a qualied
installer or service agency to re-
place 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 the water heater.
Check the data 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 that
for which the heater is congured.
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
activate the breaker/
disconnect, if the water heater is
hardwired.
3
The user interface will display
the current temperature set-
ting. The default is 120°F.
4
To change the set
temperature press the “UP”
or “DOWN” buttons to raise
or lower the temperature. See
“Temperature Adjustment/Setting the
Temperature” on page 53.
Shut-Down Instrucons
1
Press the “ON/OFF” button
and wait for the display to
shut-off.
NOTICE: The power button on the
water heater and remote DOES NOT
disconnect power to the water heater.
You must physically disconnect power
to the water heater.
Emergency Shut-Down
Should overheang occur or the gas
supply fail to shut o follow these
steps.
1
Turn off gas supply to the
water heater at the manual
shut-off valve.
2
Press the “ON/OFF” button
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.
50 • Commercial Gas Tankless Water Heater Use and Care Guide
Commercial Gas Tankless Water Heater Use and Care Guide • 51
OPERATION
Figure 42 - Lighng Instrucons
OPERATION
DISPLAY OVERVIEW
ON/OFF
DOWN
UP SETTING
E
F
G
H
B
A
C
D
Figure 43 - User Interface Display Diagram
Table 17: User Interface Display
Item Descripon
A Water Flow Detected
B Flame Detected
C Up Buon
D Down Buon
E Display
F Standby Mode
G Sengs Buon
H Operaon ON/OFF Buon
52 • Commercial Gas Tankless Water Heater Use and Care Guide
Commercial Gas Tankless Water Heater Use and Care Guide • 53
Temperature Adjustment/Seng the Temperature
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 in increments
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 below.
WARNING! Higher temperatures increase the risk of scalding, but even at 120°F, hot water can scald. Install
Thermostac Mixing Valve(s) at each point-of-use to reduce the risk of scalding.
OPERATION
Operaon
Screen on the Controller
Built-in Controller
1 Turn on the 120 VAC power supply to the water heater.
2 Press the DOWN buon to decrease the water temperature.
3
Press the UP button to increase the water temperature.
WARNING! Higher temperatures increase the risk of scalding, but even at 120 °F
(50 °C), hot water can scald (See Table 3).
NOTE: You can only increase the water temperature to 125°F. Addional steps are
required to increase the temperature above 125°F.
4
To raise the temperature above 125°F, press and hold the SETTING button for 5
seconds then release. The display will alternately flash A00 and 125°F.
4a Press the SETTING button again. The temperature setting will flash. You can
increase the temperature above 125°F.
4b Press the UP button to set the desired temperature.
4c Press the SETTING buon once to lock in the selecon, then hold the SETTING
buon to return the display to normal operaon. The new set temperature will
appear in the selected unit
(Example: 130°F).
4d The display should show the updated temperature.
Unit Conversion Mode
Table 18: Water Heater Temperature Set Points
°F
100 102 104 106 108 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185
°C
38 39 40 41 42 43 46 49 52 54 57 60 63 65 68 71 74 77 79 82 85
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 19: Unit Conversion
Operaon
Screen on the Controller
Built-in Controller
1. Turn on the 120 VAC power supply to the water heater.
2. Press the ON/OFF buon on the controller in order to turn the controller on.
3
The set point temperature will display as shown in the picture on the right (Example:
120°F).
4 Press and hold the SETTING buon for 5 seconds to access the water heater A Mode.
5
The display will show code A00. Press the UP buon once to display code A01. Press
the SETTING buon to show the current temperature seng. The temperature will
ash.
6 Press the UP buon to alternate between F (Fahrenheit) and C (Celsius).
7 Press the SETTING buon to execute the change.
8
Press and hold the SETTING buon to return the display to normal operaon. The
new set temperature will appear in the selected unit
(Example: 49°C).
OPERATION
54 • Commercial Gas Tankless Water Heater Use and Care Guide
Conguraon Mode (A Mode)
You can congure the water heater to accommodate your applicaon from A Mode. Follow the procedure below to access A
Mode:
1. Press and hold the SETTING buon for 5 seconds to access A Mode.
2. Press the UP buon or the DOWN buon to search for the desired A Code.
3. If applicable, press the SETTING buon to adjust the value. When the seng ashes, use the UP or DOWN arrows to change
the seng.
4. Press the SETTING buon again to conrm the new value selected is correct.
5. Press and hold the SETTING buon for 5 seconds to return the display to normal operaon.
Table 20: A Table Sengs
CODE DESCRIPTION OPTIONS
A00 Set Temperatures above 120°F/49°C
°F
°C
120 130 140 145 150 155 160 165 170 175 180 185
49 54 60 63 65 68 71 74 77 79 82 85
A01 Temperature Unit
°F
°C
°F, °C
OPERATION
Commercial Gas Tankless Water Heater Use and Care Guide • 55
OPERATION
Conguraon Mode (C Mode)
You can congure the water heater to accommodate your applicaon from C Mode. Follow the procedure below to access C
Mode:
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. If applicable, press the “SETTING” buon to adjust the value of the C Code using the “UP” and “DOWN” buons. The
value will ash.
4. Press the “SETTING” buon again to conrm the new value selected is correct.
5. Press and hold the “UP” buon and the “DOWN” buon for 5 seconds to return the display to normal operaon.
Table 21: C Table Sengs
CODE DESCRIPTION OPTIONS
C01 Elevaon Sengs in Feet (meters)
0:
1:
2:
3:
0 – 1,999 (default) (0 - 609)
2,000 – 5,399 (610 - 1,645)
5,400 – 7,699 (1,646 - 2,347)
7,700 – 10,100 (2,347 -3,078)
C03 Gas Type
0:
1:
Natural Gas (default)
Propane
C07 Power Frequency 60: 60Hz (default)
C08
Vent material selecon for high
temperature applicaon
0:
1:
Allowable outlet temperature less than 145°F (default)
Allowable outlet water temperature more than 145°F
C13
Number of Child Units in Cascade
System
0:
1-31:
No Cascade System (default)
Idenfy Number of Child Units. This acvates the Cascade System
C14 Cascade System Heater ID Number
1:
2-32:
Parent Heater (default)
Individually set each child unit per user preference
C15 Descaling Mode
O:
dScL:
No Descale (default)
Acvate Descale Mode
C19 Common Vent
0:
1:
Disable (default)
Enable
C20 Main Valve Controlled by Manual
0:
1:
Fully open. (default)
1 Completed Close.
NOTE This product is set to use PVC as the default vent pipe material. If the return water temperature for the applicaon is higher than 140°F (60°C) to
circulate back to the water heater, C08 must be set to ‘1’. Otherwise, the water heater will control maintain the exhaust and DHW temperatures below
149°F (65°C) and 140°F (60°C) respecvely. Note When C08 is set to ‘1’ (factory default is ‘0’), CPVC, PP, or SS vent must be used for the exhaust pipe.
56 • Commercial Gas Tankless Water Heater Use and Care Guide
Commercial Gas Tankless Water Heater Use and Care Guide • 57
OPERATION
Conguraon Mode (P Mode)
You can congure the water heater to accommodate your applicaon from P Mode. Follow the procedure below to access P
Mode:
1. Press and hold the “UP” buon and “DOWN” buon for 5 seconds to access P Mode.
2. Press the “UP” buon or the “DOWN” buon to search for the desired P Code.
3. Press and hold the “UP” buon and the “DOWN” buon for 5 seconds to return the display to normal operaon.
Table 22: P Table Sengs
CODE DESCRIPTION
P00
Heat Exchanger water outlet
temperature
Heat Exchanger water outlet temperature
P01 Domesc water outlet temperature
Water outlet temperature
P02 Domesc water inlet temperature
Water inlet temperature
P03 Domesc water ow
0.1*Gallon/min OR 0.1*L/min
P04 Fan speed
Real-me Fan speed
P05 Not applicable for this unit
Not applicable for this unit
P06 Not applicable for this unit
Not applicable for this unit
P07 Bypass Water Valve posion
The real-me posion of bypass valve
P08 Main Water Valve posion
The real-me posion of main valve
P09 AD value of ame
The value to reect ame combuson condion (the ame sensing needle
detects this value)
• Less than 140 when no ame
• Bigger than 180 when am exist. The larger the value, the greater the
boiler load
P10 Venturi Stepper motor posion
Venturi Stepper motor posion
P11 Not applicable for this unit
Not applicable for this unit
P12 1st recent historical faults
The 1st recent error code
P13 2nd recent historical faults
The 2nd recent error code
P14 3rd recent historical faults
The 3rd recent error code
P15 Flue-gas temperature
ue-gas temperature
P16 Display Soware Version No.
Front Board Soware Version
P17 Controller Soware Version No.
Main Board Soware Version
P18 Not applicable for this unit
Not applicable for this unit
P19 Model Number
199
P20 Combuson me
8-digital,2 screen display (Hour)
P21 Ignion mes record
8-digital,2 screen display
P22 Not applicable for this unit
Not applicable for this unit
P23 Not applicable for this unit
Not applicable for this unit
58 • Commercial Gas Tankless Water Heater Use and Care Guide
MAINTENANCE
CODE DESCRIPTION
P24 Venturi 0 posion combuson me
5-digital,2 screen display (Hour)
P25 Venturi 200 posion combuson me
5-digital,2 screen display (Hour)
P26 Venturi 380 posion combuson me
5-digital,2 screen display (Hour)
P27
Integrang water ow during
combuson
8-digital,2 screen display (100L)
P28 380 MAX
The corrected value
P29 380 MIN
The corrected value
P30 200 MAX
The corrected value
P31 200 MIN
The corrected value
P32 0 MAX
The corrected value
P33 0 MIN
The corrected value
P36 Number of child machines
Default (0: Parent)
Number of Children
P37 Child machine ID
Default (Parent)
Child Unit ID Number
P38 BMS acve
0 Inacve
1 Acve
Commercial Gas Tankless Water Heater Use and Care Guide • 59
MAINTENANCE
THIS PAGE INTENTIONALLY LEFT BLANK
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:
IMPORTANT! Failure to perform
required or recommended
maintenance as described in the
following secons may void the
warranty.
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 damage. Replace any damaged
secon of venng and clear any
blockage.
• 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 annually to
check for correct operaon. Before
operang the valve manually, check
that it will discharge in a place for
secure disposal.
Note that a dripping Pressure
Relief Valve is usually caused by
the building’s water pressure being
too high and/or lack of a Thermal
Expansion Tank.
• The condensate drain system must
be inspected regularly that it drains
properly in accordance with local
codes or the manufacturer’s instruc-
ons.
• The screen on the rain protecon
tray should be inspected annually
and cleaned if needed.
Rain
Protection
Tray
Figure 44 - Rain Protecon tray
Freeze Protecon System
This unit comes equipped with
heang blocks as well as the auto-
re mode 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 has to 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. .
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 “Unit
Draining & Power Outage
(Freeze Protecon)” on page 61.
2
Disconnect power to your
water heater.
60 • Commercial Gas Tankless Water Heater Use and Care Guide
Commercial Gas Tankless Water Heater Use and Care Guide • 61
Unit Draining & Power
Outage
(Freeze Protecon)
1. Close the manual gas shuto
valve.
2. Disconnect power to the wa-
ter 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
building. When the residual water
ow has ceased, close all hot
water taps.
5. Drain the Bypass Cartridge: Have
a bucket or pan to catch water
from the By-Pass Cartridge. To
remove the By-Pass 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 By-Pass Cartridge
with 3 screws removed earlier.
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 shuto to
the water heater.
12. If the set temperature is not
displayed, press the ON/OFF
buon.
13. NOTE: If any errors occur shuto
the water immediately.
Condensate Drain
• Inspect the drain lines for any clogs
and clear.
• Check the drain lines for a down-
ward slope. Correct any lines where
water does not drain freely.
• Inspect the built-in condensate trap
drain lines for debris. Disconnect
the lines and drain to remove the
debris.
• If a neutralizer is installed, check the
pH. Replace the neutralizer if the pH
of the outlet water is below 6.0.
Inlet Water Filter
If this lter is clogged, water will
not be supplied to the water heater
properly.
1. Close the manual gas shuto
valve.
2. Disconnect power to the wa-
ter 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
building. When the residual water
ow has ceased, close all hot
water taps.
5. Drain the By-Pass Cartridge: Have
a bucket or pan to catch water
from the By-Pass Cartridge. To
remove the By-Pass 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. For detailed instrucons
see “Bypass Cartridge Removal”
on page 64.
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 By-Pass Cartridge
with 3 screws removed earlier.
For detailed instrucons see
“Bypass Cartridge Installaon” on
page 64.
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
62 • Commercial Gas Tankless Water Heater Use and Care Guide
MAINTENANCE
Descaling (Flushing)
During operaon, a tankless water
heater (supplied with hard water)
accumulates hard water deposits
on the interior surfaces of the heat
exchanger. These deposits make it
dicult to transfer heat into the
water, lowering the water heater’s
eciency and causing excessive wear
to the components. Removing any
deposits is essenal to the proper
operaon and longevity of the water
heater. The X3 model should not
require descaling, however, if you
choose to descale the water heater
you must use the Bypass cartridge. A
Bypass cartridge can be ordered from
the manufacturer, p/n: 100374700.
NOTICE: DO NOT descale the water
heater using the X3 cartridge as this
may damage the cartridge media.
Tools and Materials:
• Submersible transfer pump
• 3 gallons of 5% acidity white vinegar
(food grade), available from most
grocery stores
• Washing machine hoses (2)
• Five gallon bucket
• Water heater isolaon valve kits,
installed on both the cold water
inlet and hot water outlet of the
water heater X3 Bypass Cartridge
(See Figure 46)
The water heater has a descaling
mode that will do the following to
help descale the water heater:
• Locks out the heater ring operaon
so the heater remains in standby.
• The ow control valve will stay in
the fully open posion
• The bypass water valve will move to
the fully closed posion to force the
descaling soluon through the heat
exchanger.
• The freeze protecon system will
not be acve.
1. Close the isolaon valves (C & D) to
stop the main inlet/outlet ow of
water to the house. See Figure 46.
2. Pour the white vinegar (3 gallons)
into the five gallon bucket. See
Figure 47.
3. Connect inlet hose to the transfer
pump’s discharge outlet.
Connect its opposite end to the
inlet hose connection at the cold
water inlet’s isolation valve. See
Figure 47.
4. Place the pump in the bucket
of vinegar.
5. Connect the second hose to the
outlet hose connection at the hot
water outlet. Place its loose end
into the bucket with the vinegar.
See Figure 47.
6. Open the hot and cold service
valves (A & B). See Figure 47..
7. Activate the water heater’s descaling
mode by entering the C mode.
A. Simultaniously press and hold
the UP arrow and Seng
buon for approximately 6
seconds.
A. The display will ash C00.
B. Press the UP buon or DOWN
buon to cycle to C15.
C. Press the SETTING buon
D. The display will ash OFF.
E. Press the UP buon or DOWN
buon to cycle to dScl
Figure 45 - UIM display
F. Press the SETTING buon to
acvate the descaling mode.
7. Turn power to the pump on and let it
run for approximately 45 minutes.
8. Shut off power to the pump when
descaling is complete.
9. Close service valves A & B.
See Figure 47.
10. If possible connect the outlet hose to
a drain or outside in order to flush the
water heater. If unable, go to step 12.
11. Open valve A to flush the water
heater and remove loose scale and
vinegar. Suggested flush time is
approximately 10 minutes.
Go to step 14.
12. If unable to relocate the outlet hose
to a drain or outside, confirm valves A
and B are closed.
13. Open valves C & D.
14. Open the nearest hot water fixture
to flush the water heater of any
remaining vinegar. Suggested flush
time is approximately 10 minutes.
NOTICE: DO NOT use a combined
hot and cold fixture typically found in
a shower.
15. When flushing is complete, close all
valves and remove all hoses.
16. Press the SETTING button on the
water heater’s controller.
17. Use the UP button or DOWN button
to change the display from dScL to
OFF.
18. Press the SETTING button on the
water heater’s controller.
19. Simultaniously press and hold the
UP arrow and Seng buon for
approximately 6 seconds to enter
normal operating mode.
20. Turn on the gas supply valve.
21. Open valves C & D.
22. Open the nearest hot water fixture
for a short time to test fire the heater
and make sure there are no issues.
Commercial Gas Tankless Water Heater Use and Care Guide • 63
MAINTENANCE
Expansion
Tank
Isolation Valve (C)
Isolation Valve (D)
CWS
NOTE: Condensate Drain not shown for clarity.
Water
Shutoff
Valve
HWS
Gas Line
Bypass Cartridge
Bypass
Cartridge
X3
Cartridge
DO NOT descale the water
heater using the X3 cartridge.
Inlet Hose
Connection
Outlet Hose
Connection
(B)
(A)
Figure 46 - Descaling the water heater
Isolation
Valve (C)
Isolation
Valve (D)
Hot
Service
Valve (A)
Cold
Service
Valve (B)
Outlet Hose
Connection
Inlet Hose
Connection
5 Gallon
Bucket
Submersible
Pump
3 Gallons
White Vinegar
(Food Grade)
Outlet
Hose
Inlet Hose
Figure 47 - Isolaon valve connecon points
Bypass Cartridge
The Bypass cartridge comes
pre-installed in the water heater.
WARNING! DO NOT operate water
heater without the Bypass cartridge
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.
The Bypass Cartridge must be installed
into the manifold located on the
underside of the heater cabinet prior
to operaon of the unit
X3
®
Cartridge
Bypass
Cartridge
Figure 48 - Bypass Cartridges
Bypass 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 building. When the
residual water ow has
ceased, close all hot water taps.
4
Remove the two long
(M4-25mm) screws
B
and
one short (M4-12mm) screw
A
securing the Bypass Cartridge to
the manifold located on the underside
of the water heater cabinet. Set the
screws aside in a safe place for
re-installaon. Place a bucket under
the water heater cabinet to collect
any residual water. Note the order of
the screws when removing them.
Reference Figure 49.
5
Pull down to remove the
Bypass Cartridge from the
water heater.
NOTICE: The Bypass Cartridge will be
full of water. Use cauon not to lt
the cartridge unl the water has been
drained.
A BB
AB
B
ALIGN
X3
®
CARTRIDGE
MANIFOLD
Figure 49 - Bypass Cartridge Installaon
Bypass Cartridge Installaon
1
Locate the three (3) screws
removed earlier. Set the one
M4-12mm screw
A
and two
M4-25mm screws
B
aside in a safe
place for re-installaon.
2
Locate the Bypass Cartridge.
NOTICE: Inspect o-rings for
damage or debris. Handle
with care and verify lubricant has
been properly applied to o-rings.
3
Insert the Bypass Cartridge
into manifold and secure with
the two long screws and one
short screw previously set aside in
Step 1.
NOTICE: When inserng the cartridge,
push up unl the screw holes align.
Some resistance is normal. See Figure
49.
Insert and snug all three screws by
hand. Use a screwdriver to ghten the
two
B
screws rst and lastly ghten
screw
A
. DO NOT use a drill or
impact driver to ghten the screws.
MAINTENANCE
64 • Commercial Gas Tankless Water Heater Use and Care Guide
Commercial Gas Tankless Water Heater Use and Care Guide • 65
General Troubleshoong
Table 23: Troubleshoong Chart
PROBLEM SOLUTIONS
Temperature and Amount of Hot Water
It takes a long me to
get hot water at the
xtures.
• The me 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.
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 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 operaon 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 open fully?
• 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?
• Is there enough gas in the tank / cylinder? (For Propane models)
The hot water turns
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 open fully?
• 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 supply gas pressure sucient?
• Check for cross connecon between the cold water lines and hot water lines.
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 for the lter on the cold water inlet.
• Check for reverse connecon and cross connecon.
• If you use the remote controller and/or built-in controller, is the power buon
turned on?
• Check if the inlet temperature is too high. If it is too close to the set temperature,
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
in order to re-ignite quickly, as well as purge all the
exhaust gas out of the ue.
Unit sounds abnormal
while in operaon
• Contact Technical Support Department.
TROUBLESHOOTING
66 • Commercial Gas Tankless Water Heater Use and Care Guide
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. The display will ash E and the three digit number. It will show leading zeros. Example: E002
Error codes in the cascade system are dierent. The heater number and E### (three digit number) will alternately ash on the
parent unit’s user interface module (UIM) and temperature remote controller. The child unit in error will ash the E### (three
digit number) on it’s UIM.
Consult the the table below for the descripon of each error code.
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 24: Error Code Fault Analysis
Error
Code
Error Type Procedure
E002 Hi-Limit Switches
1. Manual Hi-Limit Switch on water outlet tripped. Check the switch for proper
operaon. Press the reset buon (center of the switch), to reset it. NOTE: You
will hear and feel the switch click when reseng it.
If the high limit switch connues to trip contact a qualied service technician.
2. Automac Hi-Limit Switch on burner door tripped. If the automac Hi-limit
switch trip has occurred, it cannot be reset and must be replaced. Contact a
qualied service technician.
E006 PCB Hardware Fault
1. Check PCB wiring for loose, damaged, or cut wires/connectors. Correct any loose
connecons and replace any damaged wires/connectors. If all wires/connectors
are intact, replace the PCB.
E010 Frequency Fault
1. PCB has detected an incorrect power supply frequency. Note the default fre-
quency is 60 Hz. Conrm that C07 is set to the correct frequency of the supply
power. See Table 21 to access modes
2. If the seng is correct and the error sll occurs contact a qualied service
technician.
E011 PCB - Memory
1. The water heater will connue to operate while in this error code is ashing,
however, the recirculaon pump will be disabled. If this heater is part of a cas-
cade 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.
1. Check the ame 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.
TROUBLESHOOTING
Commercial Gas Tankless Water Heater Use and Care Guide • 67
Error
Code
Error Type Procedure
E037 False Flame Detecon
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 con-
necon and replace any damaged wire/connector. If the error sll occurs, contact
a qualied service technician.
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 and igniter wire for a short or disconnecon. Cor-
rect any loose connecons 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 Emery cloth. If the thermistor is damaged, replace it.
2. Check the 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.
E050 Inlet Thermistor Failure
1. Remove the 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.
2. Check the 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.
E051 Outlet Thermistor Failure
1. Remove the thermistor (do not lose the o-ring) and check for any dirt or debris
clean with Emery cloth. If the thermistor is damaged, replace it.
2. Check the 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.
E052
Heat Exchanger Thermistor
Failure
1. Remove the thermistor (do not lose the o-ring) and check for any dirt or debris
clean with Emery cloth. If the thermistor is damaged, replace it.
2. Check the 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.
TROUBLESHOOTING
TROUBLESHOOTING
Error
Code
Error Type Procedure
E383 Inlet Water Over-Temp.
1. Verify the inlet water temperature is not above the water heater’s set tempera-
ture.
2. Remove the inlet thermistor (do not lose the o-ring) and check for any dirt or
debris. Clean with Emery cloth. If the thermistor is damaged, replace it.
3. Check the 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.
E384 False Flame Detecon
WARNING! Working on an energized circuit can result in severe injury or death from
electrical shock.
1. Look through the sight glass for a ame. If the ame is present, immediately
shut o the gas to the water heater. Contact a qualied service technician before
aempng to use the water heater.
2. If no ame is present and the ame LED on the display is lit, Check the ame
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.
E385 Gas Valve - SV1
1. The PCB detects an incorrect voltage from the gas valve solenoid valve 1 (SV1).
Correct any loose connecons and replace any damaged wire/connector. If the
error sll occurs, contact a qualied service technician to replace the gas valve.
E388 Bypass Valve
1. Correct any loose connecons and replace any damaged wire/connector.
2. Follow the draining procedure on page 61 to properly drain the water heater.
Remove the Bypass valve and inspect for any debris or damage. Replace if
needed.
E392 Fan - False Start
1. Check the fan motor wiring. Correct any loose connecons and replace any
damaged wire/connector. If the error sll occurs, contact a qualied service
technician.
E393 Fan - Signal Loss
1. Check the fan motor wiring. Correct any loose connecons 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 connecons 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.
3. If the error sll occurs, contact a qualied service technician.
E400 Communicaon Fault with UIM
1. Check the UIM wiring. Correct any loose connecons and replace any damaged
wire/connector. If the error sll occurs, contact a qualied service technician.
68 • Commercial Gas Tankless Water Heater Use and Care Guide
Commercial Gas Tankless Water Heater Use and Care Guide • 69
Error
Code
Error Type Procedure
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
damaged wire/connector.
2. Cycle the heater’s power o/on if the cascade wiring was disconnected while the
system sll had power.
3. If the error sll occurs, contact a qualied service technician.
E403 Fan - Low Speed
1. Check the fan motor wiring. Correct any loose connecons 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.
3. If the error sll occurs, contact a qualied service technician.
E411
Heat Exchanger - Water
Overheang.
1. Remove the heat exchanger 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.
2. Check the 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.
E412 Flame Signal Fault
1. Remove the ame sensor (do not lose the gasket) and check for any dirt or debris
on the surface of ame sensor rod, also inspect inside of the installaon hole of
the heat exchanger. Remove any debris on the surface and inside the hole.
2. Reinstall install the ame sensor rod (secure with two screws).
3. If the error sll occurs, contact a qualied service technician.
E413 Flame Sensor
1. Check the ame sensor wire for a short or disconnecon. Correct any loose con-
necons 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 Combuson
and Venng Installaon secon in the manual.
4. Check the installaon area for corrosive elements, reference the see Installaon
Environment secon in the manual.
5. If the error sll occurs, contact a qualied service technician.
TROUBLESHOOTING
TROUBLESHOOTING
Error
Code
Error Type Procedure
E414 PCB-Flame Sensor Circuit
1. Check the ame sensor wire for a short or disconnecon. Correct any loose con-
necons and replace any damaged wire/connector.
2. If the error sll occurs, contact a qualied service technician to replace the PCB.
E415 Gas Valve Fault
1. Check the gas valve wiring for a short or disconnecon. Correct any loose con-
necons and replace any damaged wire/connector.
2. If the error sll occurs, contact a qualied service technician.
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.
E417 Flame Sensor Fault
1. Check the ame sensor wire for a short or disconnecon. Correct any loose con-
necons and replace any damaged wire/connector.
2. Check the inlet & heat exchanger thermistor sensor wires for a short or discon-
necon. Correct any loose connecons and replace any damaged wire/connec-
tor.
3. Remove the inlet & heat exchanger thermistors (do not lose the o-ring) and
check for any dirt or debris. Clean with an Emery cloth. If the either thermistor is
damaged, replace it.
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 exhaust thermistor (do not lose the o-ring) and check for any dirt or
debris clean with Emery cloth. If the thermistor is damaged, replace it.
3. If the error sll occurs, contact a qualied service technician.
E420 Gas Valve - SV2
1. PCB detects an incorrect voltage from the gas valve’s SV2. Correct any loose
connecons and replace any damaged wire/connector. If the error sll occurs
contact a qualied service technician to replace the gas valve.
E421 Pressure Switch
1. Check the pressure switch wires for a short or disconnecon. Correct any loose
connecons and replace any damaged wire/connector.
2. Check the pressure tube for loose connecons, debris, or blockages. Correct any
issue immediately.
3. With the water heater power disconnected, check the exhaust vent and air
intake piping for any blockages. Remove any blockages.
4. If the error sll occurs, contact a qualied service technician.
E422 Venturi Assembly
1. Check the venturi assembly wires for a short or disconnecon. Correct any loose
connecons and replace any damaged wire/connector.
2. If the error sll occurs, contact a qualied service technician.
70 • Commercial Gas Tankless Water Heater Use and Care Guide
Commercial Gas Tankless Water Heater Use and Care Guide • 71
Error
Code
Error Type Procedure
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. Remove
any blockages.
3. With the water heater o, check the condensate trap for any blockages. Remove
any blockages.
4. Check the condensate drain wires for a short or disconnecon. Correct any loose
connecons and replace any damaged wire/connector.
5. Verify the condensate drain line is installed correctly, reference “Condensate
Drain” on page 45.
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 but-
ton 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 con-
necons 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.
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.
E430
Combuson Suspended Due To
High Flue-Gas Temperature
1. Vent material selected for high-temperature applicaons and set C08 = 1 in
C-mode. Refer Table 7: Plasc Vent Pipe Table
TROUBLESHOOTING
TROUBLESHOOTING
1
18
22
3
20
4
6
21
14
24
13
2
7
12
33
27
72 • Commercial Gas Tankless Water Heater Use and Care Guide
Commercial Gas Tankless Water Heater Use and Care Guide • 73
COMPONENT LIST
18
22
3
5
6
4
27
20
14
26
12
10
23
25
21
16
8
9
15
19
7
COMPONENT LIST
18
3
5
6
20
14
7
12
10
21
16
22
15
23
74 • Commercial Gas Tankless Water Heater Use and Care Guide
Commercial Gas Tankless Water Heater Use and Care Guide • 75
COMPONENT LIST
28
17
31
30
29
32
COMPONENT LIST
76 • Commercial Gas Tankless Water Heater Use and Care Guide
Commercial Gas Tankless Water Heater Use and Care Guide • 77
COMPONENT LIST
Replacement parts may be ordered through your local distributor or by calling our Technical Assistance Hotline which is
listed on your warranty. When ordering parts, always give the following informaon:
1. Model and serial numbers. This info should be on the le side of the water heater
2. Part(s) descripon
Item
No.
Component List
1 AIR PRESSURE SWITCH
2 CONDENSATE TRAP
3 BURNER DOOR HI-LIMIT
4 FLAME SENSOR
5 HEAT EXCHANGER THERMISTOR
6 HI-LIMIT SWITCH (MANUAL RESET)
7 GAS VALVE
8 USER INTERFACE
9 PRINTED CIRCUIT BOARD
10 INLET FILTER
11 X
3
CARTRIDGE (Not Shown)
12 BYPASS CARTRIDGE
13 OUTLET WATER TUBE
14 BYPASS WATER TUBE
15 HEAT EXCHANGER OUTLET WATER TUBE
16 INLET WATER TUBE
17 CASE (FRONT COVER NOT SHOWN FOR CLARITY)
18 EXHAUST THERMISTOR
19 IGNITER RODS
20 BURNER ASSEMBLY
21 FAN
22 IGNITER
23 FLOW SENSOR/FLOW CONTROL VALVE ASSEMBLY
24 BYPASS VALVE
25 INLET THERMISTOR
26 OUTLET THERMISTOR
27 VENTURI ASSEMBLY
28 CASE FRONT COVER
29 MOUNTING BRACKETS
30 EXHAUST PORT
31 INLET PORT
32 OUTDOOR VENT CAP
33 HEAT EXCHANGER ASSEMBLY
78 • Commercial Gas Tankless Water Heater Use and Care Guide
CHAPTER HEADER
FLOW RATE CAPACITY CHART
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 de-
rate approximately 3% (NG) or 4.5% (LP) 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)
CTH Flow Rate Capacity Chart
THR-199
Temperature Rise (°F)
Commercial Gas Tankless Water Heater Use and Care Guide • 79
GPM VS PRESSURE LOSS CHART
GPM vs Pressure Loss Chart
GPM vs Pressure Loss Chart
Gpm Vs Pressure Loss Chart
Pressure Loss (PSI)
GPM (Flow Rate)
NOTES
NOTES
NOTES
NOTES
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