Takagi T-H3S-DV User manual

Gas Tankless Water HeaterTM
Suitable for potable water heating and space-heating
Please refer to local codes for space-heating compliance.
540 (T-H3)
model only
If you have any questions, please
call or write to:
500 Tennessee Waltz Parkway
Ashland City, TN 37015
Toll Free: 1-877-737-2840
WARNING
- Do not store or use gasoline or other
flammable vapors and liquids in the vicinity
of this or any other appliance.
- WHAT TO DO IF YOU SMELL GAS
 • Donottrytolightanyappliance.
 • Donottouchanyelectricswitch,donot
use any phone in your building.
 • Immediatelycallyourgassupplierfrom
a neighbor's phone. Follow the gas
supplier's instructions.
 • Ifyoucannotreachyourgassupplier,call
the fire department.
- Installation and service must be performed
by a qualified installer, service agency or the
gas supplier.
On-Demand Water Heater
Installation Manual and Owner’s Guide
ANSI Z21.10.3 and CSA 4.3
If the information in these
instructions is not followed
exactly, a fire or explosion may
result causing property damage,
personal injury or death.
FEATURING
 • ENDLESSHOTWATER
 • ON-DEMANDUSAGE
 • COMPACT,SPACESAVING
 • ENERGYCONSERVATION
 • COMPUTERIZEDSAFETY
 • NOPILOTLIGHT
 • Satisfiesthe2012SCAQMDRule
1146.2 for Ultra-Low NOx
Emissions
 • EASY-LINKSYSTEMAND
MULTI-UNIT SYSTEM
(540 (T-H3) model only)
Models
• 240Outdoor(T-H3J-OS)
• 340Outdoor(T-H3S-OS)
• 540Outdoor(T-H3-OS)
• 240Indoor(T-H3J-DV)
• 340Indoor(T-H3S-DV)
• 540Indoor(T-H3-DV)

2Page
CONTENTS
Installation Manual
SPECIFICATIONS.......................................................................................................................... 4
INTRODUCTION .......................................................................................................................... 5
SAFETY GUIDELINES.................................................................................................................... 6
INSTALLATION............................................................................................................................. 7
General.....................................................................................................................................7
Clearances................................................................................................................................9
Included accessories................................................................................................................9
Optional items..........................................................................................................................9
Warning for installations........................................................................................................11
High-altitudeinstallations......................................................................................................12
Ventinginstructions...............................................................................................................13
Gas supply and gas pipe sizing...............................................................................................25
Water connections................................................................................................................27
Condensate drain..................................................................................................................28
Electrical connections............................................................................................................30
Temperature remote controller............................................................................................31
Easy-Link System....................................................................................................................33
Multi-UnitSystem..................................................................................................................37
APPLICATIONS............................................................................................................................38
INITIAL OPERATION...................................................................................................................40
Owner's Guide
OPERATING SAFETY .................................................................................................................. 42
NORMAL OPERATION ............................................................................................................... 44
Temperature controller and Remote controller.....................................................................44
General...................................................................................................................................44
Temperaturesettings.............................................................................................................45
Temperature table of controller.............................................................................................45
Additionalfeatures.................................................................................................................46
Temperature settings on the PCB (Without remote controller)............................................47
Flow.......................................................................................................................................48
Freeze protection system.......................................................................................................48
Maintenance and service.......................................................................................................49
Unit draining and filter cleaning............................................................................................49
TROUBLESHOOTING...................................................................................................................50
General...................................................................................................................................50
Error codes............................................................................................................................52
COMPONENTSDIAGRAM...........................................................................................................55
PARTS LIST.....................................................................................................................................59
OUTPUT TEMPERATURE CHART..................................................................................................62
LIMITED WARRANTY..................................................................................................................63
Contents

3Page
Installaon Manual
Installation Manual
CONGRATULATIONS
Congratulations and thank you for choosing our tankless water heater.
Before use, we recommend that you read through this safety manual
carefully. Please refer to the back of the manual for details about the
warranty. Keep this manual for future reference.
If you lose the manual, contact the manufacturer or your local
distributor. When you call, please tell us the model number and the
serial number of your unit written on the rating plate of the water
heater.

4Page
Specicaons
Installaon Manual
SPECIFICATIONS
*40 psi or above is recommended for maximum flow.
** The Manifold Pressure is the factory setting and generally should not need adjustment.
NOTE:
• Checktheratingplatetoensurethisproductmatchesyourspecifications.
• InaccordancewithANSIZ21.10.3,COemissiondoesnotexceed400PPMfornormalinput.
• The manufacturer reserves the right to discontinue, or change at any time, specifications or designs
without notice and without incurring obligation.
Model 240
Indoor
(T-H3J-DV)
240
Outdoor
(T-H3J-OS)
340
Indoor
(T-H3S-DV)
340
Outdoor
(T-H3S-OS)
540
Indoor
(T-H3-DV)
540
Outdoor
(T-H3-OS)
Natural Gas Input
(Operating Range) BTU/h Min.:15,000 Max.:160,000
Min.:15,000
Max.:180,000
Min.:15,000
Max.:199,000
Propane Input
(Operating Range) BTU/h Min.:13,000 Max.:160,000
Min.:13,000
Max.:180,000
Min.:13,000
Max.:199,000
Gas Connection 3/4" NPT
Water Connections 3/4" NPT
Water Pressure* psi
(MPa) 15-150(0.1-1)
Natural gas
Inlet Pressure
" W.C.
(kPa)
Min.5.0(1.24)
Max.10.5(2.61)
Propane
Inlet Pressure
" W.C.
(kPa)
Min.8.0(1.99)
Max.14.0(3.48)
Manifold
Pressure**
Natural
Gas
" W.C.
(Pa)
1.50
(373)
1.70
(423)
2.45
(610)
2.1
(523)
2.95
(734)
2.70
(672)
Propane " W.C.
(Pa)
2.10
(523)
1.90
(473)
2.7
(672)
2.55
(635)
3.3
(821)
3.15
(784)
Weight lbs. (kg) 58(26.3) 58(26.2) 58(26.3) 58(26.2) 59(26.8) 59(26.9)
Dimensions inch H22.4xW17.7xD10.7
H570xW450xD272
mm
Ignition Electric Ignition
Electric
Supply VAC / Hz 120/60
Consumption
Operation W / A 72.7/0.61 78.2/0.65 89.0/0.74
Standby W / A 3.1/0.03 3.1/0.03 4.2 / 0.04
Freeze-
Protection W / A 174/1.5 174/1.5 175/1.5

5Page
INTRODUCTION
• This manual provides information necessary for the installation, operation, and maintenance
of the water heater.
• The model description is listed on the rating plate which is attached to the side panel of the
water heater.
• Please read all installation instructions completely before installing this product.
• If you have any problems or questions regarding this equipment, consult the manufacturer or
its local representative.
• This equipment is an on-demand, tankless water heater designed to efficiently supply endless
hot water for your needs.
• These high efficiency models have a built-in secondary heat exchanger that absorbs latent
heat from the exhaust gas.
• The 240 Indoor (T-H3J-DV), 340 Indoor (T-H3S-DV) and 540 Indoor (T-H3-DV) models are
onlytobeinstalledindoors.The240Outdoor(T-H3J-OS),340Outdoor(T-H3S-OS)and540
Outdoor (T-H3-OS) models are only to be installed outdoors.
• The principle behind tankless water heaters is simple:
*This diagram illustrates tankless water heater design concepts only and does not accurately
represent the water heater’s physical description.
1. A hot water tap is turned on.
2. Water enters the heater.
3. The water flow sensor detects the water flow.
4. The computer initiates the fan motor and sends a signal to the igniter to create an ignition spark.
5. The gas ignites and flames appear within the burner chamber.
6. Water circulates through the heat exchanger and then gets hot.
7. Using thermistors to measure temperatures throughout the water heater, the computer modulates
the gas and water valves to ensure proper output water temperature.
8. When the tap is turned off, the unit shuts down.
Introducon
Installaon Manual
Exhaust
Secondary
heat exchanger
Intake port
Condensate
drain port
Cold water inlet
Gas
Hot water outlet
Computer board Fan motor
Gas valves
Thermistor
Thermistor
Bypass valve
Primary
heat exchanger
Exhaust thermistor
Water control valve
Thermistor
Flow sensor
Burners

6Page
SAFETY GUIDELINES
SAFETY DEFINITION
GENERAL
1. Follow all local codes, or in the absence of local codes, follow the most recent edition of the National
FuelGasCode:ANSIZ223.1/NFPA54intheUSAorCAN/CSAB149.1NaturalGas,PropaneInstallation
Code in Canada.
2. Properly ground the unit in accordance with all local codes or in the absence of local codes, with the
NationalElectricalCodes:ANSI/NFPA70intheUSAorCSAstandardC22.1CanadianElectricalCode
Part1inCanada.
3. Carefully plan where you intend to install the water heater. Please ensure:
•Yourwaterheaterwillhaveenoughcombustibleairandproperventilation.
•Locateyourheaterwherewaterleakagewillnotdamagesurroundingareas.(Pleasereferto
p.8.)
4. Check the rating plate for the correct GAS TYPE, GAS PRESSURE, WATER PRESSURE and ELECTRIC
RATING.
*If this unit does not match your requirements, do not install and consult with the manufacturer.
5. If any problem should occur, turn off all hot water taps and turn off the gas. Then call a trained
technician or the Gas Company or the manufacturer.
WARNING
Indicates an imminently hazardous situation which, if not avoided, could result
in death or serious injury.
CAUTION
Indicates an imminently hazardous situation which, if not avoided, could result
in minor or moderate injury.
Safety Guidelines
Installaon Manual
Indicates an imminently hazardous situation which, if not avoided, will result in
death or serious injury.
DANGER
WARNING
• 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.
• Do not store or use gasoline or other flammables, vapors, or liquids in the
vicinity of this appliance.
• Do not reverse the water and/or gas connections as this will damage the gas
valves and can cause severe injury or death. Follow the diagram on p. 27
when installing your water heater.
• Do not use this appliance if any part has been in contact with or been
immersed in water. Immediately call a licensed plumber, a licensed gas
fitter, or a professional service technician to inspect and/or service the unit if
necessary.
• Do not disconnect the electrical supply if the ambient temperature will drop
below freezing. The Freeze Protection System only works if the unit has
electrical power. The warranty will not be covered if the heat exchanger
is damaged due to freezing. Refer to the section on the Freeze Protection
Systemonp.48formoreinformation.

7Page
INSTALLATION
GENERAL
1. Follow all local codes, or in the absence of local codes, follow the most recent edition of the National
FuelGasCode:ANSIZ223.1/NFPA54intheUSAorCAN/CSAB149.1NaturalGas,PropaneInstallation
Code in Canada.
2. All gas water heaters require careful and correct installation to ensure safe and efficient operation.
This manual must be followed exactly. Read the “Safety Guidelines” Section.
3. The manifold gas pressure is preset at the factory. It is computer controlled and should not need
adjustment.
4. Maintain proper space for servicing. Install the unit so that it can be connected or removed easily.
Refertothe"Clearances"Sectiononp.9forproperclearances.
5. The water heater must be installed in a location where the proper amount of combustible air will be
available to it at all times without obstructions.
6. The electrical connection requires a means of disconnection, to terminate power to the water heater
for servicing and safety purposes.
7. Do not install the unit where the exhaust vent is pointing into any opening in a building or where the
noise may disturb your neighbors. Make sure the vent termination meets the required distance by
local code from any doorway or opening to prevent exhaust from entering a building. (Refer to p. 22.)
8. Particles from flour, aerosols, and other contaminants may clog the air vent, build up and reduce
the functions of the rotating fan, cause improper burning of the gas, or cause damage to the water
heater. Regularly ensure that the area around the unit is dust- or debris-free. Regular maintenance is
recommended for these types of environment.
9. The240Indoor(T-H3J-DV),340Indoor(T-H3S-DV),and540Indoor(T-H3-DV)aretobeinstalled
indoors only. These units are equipped with a thermistor and hi-limit switch for the exhaust gas,
detecting excess temperatures within the flue and enabling the unit to safely stop operations if
needed. These components are always monitoring exhaust gas conditions in order to prevent heat
damage to ABS, PVC, CPVC, or polypropylene (Plastic) venting if ABS, PVC, CPVC, or polypropylene
isused.Iftheexhaustgastemperatureexceeds140°F,thesecomponentswillenabletheunitto
safely stop operations. These components are not installed on the outdoor models since the exhaust
vent is built-in.
•The Indoor model requires a 3 in. or 4 in. make-up intake air supply pipe. The intake pipe must
be sealed airtight.
•Air supply pipe can be made of ABS, PVC, CPVC, polypropylene, corrugated stainless steel, or
Categorylll/IVstainlesssteel.Regardingexhaustpipe,refertop.13and15.
•Sidewall venting is recommended for the Indoor model. Vertical venting (roof termination) is
acceptable.
•The manufacturer recommends running the exhaust vent and the intake pipe as parallel as possible.
10.The240Outdoor(T-H3J-OS),340Outdoor(T-H3S-OS),and540Outdoor(T-H3-OS)modelsonlytobe
installed outdoors and only in the area with mild, temperate climates.
The Outdoor model shall be wall-mounted or mounted on a stand. Locate the Outdoor model in an
open, unroofed area and maintain the following minimum clearances:
There is a 2 in. clearance from the left and right sides of the unit to combustible and
non-combustible surfaces.
Installaon
Installaon Manual

8Page
INCLUDED ACCESSORIES
OPTIONAL ITEMS
• Installation and service must be performed by a qualified installer (for
example, a licensed plumber or gas fitter), otherwise the warranty will be
void.
• The installer (licensed professional) is responsible for the correct installation
of the water heater and for compliance with all national, state / provincial,
and local codes.
• The manufacturer does not recommend installing the water heater in a pit or
location where gas and water can accumulate.
• Do not have the vent terminal pointing toward any operating window, door, or
opening into a building.
• Do not install next to any source of airborne debris, such as a clothes dryer,
that can cause debris to be trapped inside the combustion chamber, unless the
system is direct-vented.
• The manufacturer does not recommend installing the water heater in an attic
due to safety issues. If you install the water heater in an attic:
• Make sure the unit will have enough combustion air and proper
ventilation.
• Keep the area around the water heater clean. When dust collects on the
flame sensor, the water heater will shut down on an error code.
• Place the unit for easy access for service and maintenance.
• A drain pan, or other means of protection against water damage, is
required to be installed under the water heater in case of leaks.
WARNING
• The warranty will not cover damage caused by water quality.
• Only potable water or potable water / glycol mixtures can be used with
this water heater. Do not introduce pool or spa water, or any chemically
treated water into the water heater.
• Waterhardnesslevelsmustnotexceed7grainspergallon(120ppm)for
single family domestic applications or more than 4 grains per gallon (70
ppm) for all other types of applications. Water hardness leads to scale
formation and may affect / damage the water heater. Hard water scaling
must be avoided or controlled by proper water treatment.
• WaterpHlevelsmustbebetween6.5and8.5
• Well water must be treated.
• Do not install the unit where water, debris, or flammable vapors may get into
the flue terminal.
• Although the water heater is designed to operate with minimal sound, the
manufacturer does not recommend installing the unit on a wall adjacent to a
bedroom, or a room that is intended for quiet study or meditation, etc.
• Locate your heater close to a drain where water leakage will not do damage
to surrounding areas. As with any water heating appliance, the potential for
leakage at some time in the life of the product does exist. The manufacturer
will not be responsible for any water damage that may occur. If you install a
drain pan under the unit, ensure that it will not restrict the combustion air flow.
CAUTION
Installaon
Installaon Manual

9Page
Maintain all clearances around
the water heater.
CLEARANCES
Installaon
Installaon Manual
Model Top Bottom Front Back Sides
240 Indoor (T-H3J-DV)
340 Indoor (T-H3S-DV)
540Indoor(T-H3-DV)
12in.
(305mm)
12in.
(305mm)
4 in.*
(102mm)
0.5in.
(13mm)
2 in.
(51mm)
240 Outdoor (T-H3J-OS)
340 Outdoor (T-H3S-OS)
540Outdoor(T-H3-OS)
36in.
(914mm)
12in.
(305mm)
24 in.
(610mm)
0.5in.
(13mm)
2 in.
(51mm)
*24 inches recommended for maintenance.
OPTIONAL ITEMS
Back
Side
Front
Side
Top
Boom
INCLUDED ACCESSORIES
Check that these items below are included with the water heater.
Installation manual
and owner’s guide
Temperature remote controller kit*
Outdoor models only
Bird screen
Indoor models only
Communication cable
540 (T-H3) model only
Qty:1 Qty:1
Qty:1
*Refertop.31.
Qty: 2
#Model
240
Indoor
(T-H3J-DV)
240
Outdoor
(T-H3J-OS)
340
Indoor
(T-H3S-DV)
340
Outdoor
(T-H3S-OS)
540
Indoor
(T-H3-DV)
540
Outdoor
(T-H3-OS)
1. Temperature remote
controller ✓ ✓ ✓ ✓ ✓ ✓
2. Pipe cover ✓ ✓ ✓ ✓ ✓ ✓
3. Neutralizer kit ✓ ✓ ✓ ✓ ✓ ✓
4.
Sidewall vent
terminator (Hood)
and Wall thimble ✓ ✓ ✓
5. 3" PVC concentric
termination ✓ ✓ ✓
6. Non-return valve ✓ ✓ ✓

10 Page
Installaon
Installaon Manual
3. Neutralizer kit: 9007607005 (TH-NT01)
The neutralizer assembly neutralizes the condensate (acidic water) that forms in the
secondary heat exchanger of the water heater.
It connects to the condensate drain port of the water heater by using connectors
includedwiththeneutralizerkit.(Refertop.29.)
The temperature remote controller
has two functions. It allows the
output temperature from the water
heater to be adjusted within the range
of100°Fto185°F,anditalsoworks
as a diagnostic tool that will give a
concise error code whenever there is
a problem with the unit.
1. Temperature remote controller:
9008172005 (TM-RE40)
5. 3" PVC concentric termination: 9007611005 (TH-CVPVC33)
Used when terminating direct-vent (sealed combustion)
systems,withIndoormodelsthatrequirea3in.(76mm)intake
anda3in.(76mm)exhaust.
The pipe cover protects the plumbing pipes to
the water heater from unexpected adjustments.
This pipe cover is fixed to the bottom of the water
heater, which hides the plumbing and improves
the visual aspects of the whole installation for
the water heater.
2. Pipe cover: 9008331005 (TH-PC03)
4. Sidewall vent terminator (Hood) and Wall thimble:
They are used when venting out through the wall. These terminations are special stainless steel vents
for gas appliances and are UL listed as Category II, III and IV. For different wall thicknesses, there
are two ranges of lengths available. (Refer to the NovaVent brochure for details.) Install these vent
terminations in accordance with their installation instructions and any applicable local codes.
Covering wall thicknesses Part#
Terminator Hood 9007999005
Wall Thimble 4 - 7 in. 9008345005
WallThimble5-10in. 9008346005
Termination + Thimble 4 - 7 in. 9008004005
Termination+Thimble5-10in. 9008005005
Wall Thimble
Terminator Hood
6. Non-return valve: 9008847005
It is a must-have item for common venting system. It prevents
the escape of combustion gas through non-operating appliances.
(Refertop.20and21.)
The temperature options are 100 °F, 105 °F, 110
°F,115°F,120°F,125°F,130°F,135°F,140°F,145
°F,150°F,155°F,160°F165°F,175°Fand185°F.
See the Troubleshooting Section for information on
possible error codes.
This concentric termination provides the convenience of only having to make one penetration through a
sidewall instead of two separate penetrations for the intake and exhaust piping. The termination includes
a bird screen, restricting small animals, pests, and foreign objects from entering into the vent system.

11 Page
WARNING FOR INSTALLATIONS
FOR YOUR SAFETY, READ BEFORE INSTALLATION:
Do not install the heater where water, debris or
flammable vapors may get into the flue terminal.
This may cause damage to the heater and void the
warranty.
Do not have the vent terminal pointing toward
any opening into a building. Do not locate your
heater in a pit or location where gas and water
can accumulate.
Do not install this water heater under an
overhanglessthan3ft.(914mm)fromitstop
or eaves. The area under an overhang must be
open to three sides (Outdoor models only).
Do not install the water heater vent terminator
within1ft.(305mm)in the USA of any air intake
or building opening, and within 3 ft. (914 mm)
in Canada of any air intake or building opening
(Outdoor models only, refer to p. 22).
Do not install next to a dryer or any source
of airborne debris that can be trapped inside
the combustion chamber, unless the system is
direct-vented.
ProhibitedProhibited
3 ft.
(914mm)
1ft.(305mm)USA
3ft.(914mm)Canada
1ft.(305mm)USA
3ft.(914mm)Canada 1ft.(305mm)USA
3ft.(914mm)Canada
Installaon
Installaon Manual

12 Page
HIGH-ALTITUDE INSTALLATIONS
Check the elevation where your water heater is installed. Set DIPswitches shown in the table below
depending on the altitude.
WARNING
DO NOT adjust any DIPswitches on the upper bank for the 540 (T-H3)
model.
Installaon
Installaon Manual
NOTE: The dark squares indicate the direction the DIPswitches should be set to.
540 (T-H3) model
Computer board
Lower bank of DIPswitches
Outdoor models
0 to 2,000 ft.
(DEFAULT)
2,000 to
4,000 ft.
4,000 to
6,000 ft. Over 6,000 ft
240 (T-H3J) and
340 (T-H3S) models No. 3 : OFF
No. 4 : OFF
No. 5: OFF
No. 3 : OFF
No. 4 : OFF
No. 5: ON
No. 3 : ON
No. 4 : OFF
No. 5: ON
Consult our
Technical
Services
at1-877-
737-2840
540(T-H3)model
(Lower bank of
DIPswitches) No. 2 : OFF
No. 3 : OFF
No. 4 : OFF
No. 2 : OFF
No. 3 : OFF
No. 4 : ON
No. 2 : ON
No. 3 : OFF
No. 4 : ON
OFF
ON
1 2 3 4 5 6 7 8 9 10
OFF
ON
12345678910
OFF
ON
1 2 3 4 5 6 7 8 9 10
OFF
ON
1 2 3 4 5 6
OFF
ON
1 2 3 4 5 6
OFF
ON
1 2 3 4 5 6
Bank of DIPswitches
240 (T-H3J) and 340 (T-H3S) models
Computer board
Indoor models
0 to 2,000 ft.
(DEFAULT)
2,000 to
3,000 ft.
3,000 to
5,000 ft.
5,000 to
7,500 ft.
7,500 to
10,100 ft.
240 (T-H3J) and
340 (T-H3S) models No. 3 : OFF
No. 4 : OFF
No. 5: OFF
No. 3 : OFF
No. 4 : ON
No. 5: OFF
No. 3 : OFF
No. 4 : OFF
No. 5: ON
No. 3 : OFF
No. 4 : ON
No. 5: ON
No. 3 : ON
No. 4 : ON
No. 5: ON
540(T-H3)model
(Lower bank of
DIPswitches) No. 2 : OFF
No. 3 : OFF
No. 4 : OFF
No. 2 : OFF
No. 3 : ON
No. 4 : OFF
No. 2 : OFF
No. 3 : OFF
No. 4 : ON
No. 2 : OFF
No. 3 : ON
No. 4 : ON
No. 2 : ON
No. 3 : ON
No. 4 : ON
OFF
ON
1 2 3 4 5 6 7 8 9 10
OFF
ON
1 2 3 4 5 6 7 8 9 10
OFF
ON
12345678910
OFF
ON
12345678910
OFF
ON
1 2 3 4 5 6
OFF
ON
1 2 3 4 5 6
OFF
ON
1 2 3 4 5 6
OFF
ON
1 2 3 4 5 6
Altitude
DIPswitches
OFF
ON
12345678910
OFF
ON
1 2 3 4 5 6

13 Page
VENTING INSTRUCTIONS
For the 240 Indoor (T-H3J-DV), 340 Indoor (T-H3S-DV) and 540 Indoor (T-H3-DV) models
-General-
The Indoor models must be vented in accordance with the section “Venting of Equipment" of the latest
editionoftheNationalFuelGasCode:ANSIZ223.1/NFPA54intheUnitedStatesand/orSection7ofthe
CAN/CSAB149.1NaturalGasandPropaneInstallationCodeinCanada,aswellasapplicablelocalbuilding
codes.
The use of venting materials approved for Category III/IV appliances is recommended whenever possible.
However, the Indoor models may also be vented with plastic pipe materials such as ABS, PVC, CPVC, or
polypropylene. For details, please refer to the Exhaust Vent (ABS, PVC, CPVC, or Polypropylene Vent)
Section on p. 15. Vent installations in Canada which utilize plastic vent systems must use venting that
complieswithULCS636.
General rules for venting water heaters are:
• Place the water heater as close as possible to the vent termination.
• The vent collar of the water heater must be fastened directly to an unobstructed vent pipe.
• Do not weld the vent pipe to the water heater’s vent collar.
• Do not cut the vent collar of the unit.
• The vent must be easily removable from the top of the water heater for normal service and
inspection of the unit.
• The water heater vent must not be connected to any other gas appliance or vent stack except an
approvedcommon-ventingsystem.(Refertop.20and21.)
• Avoid using an oversized vent pipe or using extremely long runs of the pipe unless it is part of an
approved common vent system.
• For rooftop venting, a rain cap or other form of termination that prevents rain water from
entering into the water heater must be installed.
• Do not terminate vent into a chimney. If the vent must go through the chimney, the vent must
run all the way through the chimney with approved vent pipe.
General rules for vent terminations:
• Avoid locating the water heater vent termination near any air intake devices. These fans can
pick up the exhaust flue products from the water heater and return them to the building. This
can create a health hazard.
• Locate the vent termination so that it cannot be blocked by any debris, at any time. Most codes
require that the termination be at least 12 in. (305 mm) above grade, but the installer may
determine if it should be higher depending on the job site condition and applicable codes.
• A proper sidewall termination is recommended when the water heater is vented through a
sidewall.
• Regarding the clearances from the exhaust termination to the air inlet or opening, refer to p. 22
to 24.
• Improper venting of this appliance can result in excessive levels of carbon
monoxide which can result in severe personal injury or death.
• Improper installation can cause nausea or asphyxiation, severe injury or death
from carbon monoxide and flue gases poisoning. Improper installation will
void product warranty.
DANGER
When installing the vent system, all applicable national and local codes must be
followed. If you install thimbles, fire stops or other protective devices and they
penetrate any combustible or noncombustible construction, be sure to follow all
applicable national and local codes.
CAUTION
Installaon
Installaon Manual

14 Page
-DIPswitch settings for Vent length-
4" venting
Vent length 240 Indoor (T-H3J-DV)
340 Indoor (T-H3S-DV)
540 Indoor (T-H3-DV)
(Upper bank of DIPswitches)
5 to 50 ft.
(DEFAULT) No.6:ON
No. 7 : OFF
No. 3 : ON
No. 4 : OFF
51 to 100 ft.
No.6:OFF
No. 7 : OFF
No. 3 : OFF
No. 4 : OFF
OFF
ON
1 2 3 4 5 6 7 8
OFF
ON
1 2 3 4 5 6 7 8
OFF
ON
1 2 3 4 5 6 7 8 9 10
OFF
ON
1 2 3 4 5 6 7 8 9 10
3" venting
Vent length 240 Indoor (T-H3J-DV)
340 Indoor (T-H3S-DV)
540 Indoor (T-H3-DV)
(Upper bank of DIPswitches)
5 to 20 ft.
(DEFAULT) No.6:ON
No. 7 : OFF
No. 3 : ON
No. 4 : OFF
21 to 40 ft.
No.6:OFF
No. 7 : OFF
No. 3 : OFF
No. 4 : OFF
41 to 70 ft.
No.6:ON
No. 7 : ON
No. 3 : ON
No. 4 : ON
OFF
ON
1 2 3 4 5 6 7 8
OFF
ON
1 2 3 4 5 6 7 8
OFF
ON
1 2 3 4 5 6 7 8 9 10
OFF
ON
1 2 3 4 5 6 7 8 9 10
OFF
ON
1 2 3 4 5 6 7 8
OFF
ON
1 2 3 4 5 6 7 8 9 10
Set DIPswitches shown in the tables below depending on the vent length.
3" venting
Vent length 240 Indoor (T-H3J-DV)
340 Indoor (T-H3S-DV)
540 Indoor (T-H3-DV)
(Upper bank of DIPswitches)
5 to 45 ft.
(DEFAULT) No.6:ON
No. 7 : OFF
No. 3 : ON
No. 4 : OFF
46 to 70 ft.
No.6:OFF
No. 7 : OFF
No. 3 : OFF
No. 4 : OFF
OFF
ON
1 2 3 4 5 6 7 8
OFF
ON
1 2 3 4 5 6 7 8
OFF
ON
1 2 3 4 5 6 7 8 9 10
OFF
ON
1 2 3 4 5 6 7 8 9 10
Set DIPswitches shown in the table below depending on the vent length.
<Single pipe with room-air intake installaon>
<Two-pipe, direct-vent installaon>
Installaon
Installaon Manual
Refertop.16fordetails.
Refertop.17fordetails.

15 Page
-Exhaust vent (ABS, PVC, CPVC, or polypropylene vent)-
The Indoor models can be vented with ABS, PVC, CPVC, or polypropylene (temperature rated up to
149°F).VentmaterialcertifiedtoULCS636standardsisrecommendedintheUSA.InCanada,plastic
ventingmustbecertifiedtoULCS636standards.
• Themaximumlengthofexhaustventpipingmustnotexceed70ft.(21.3m)for3”venting,which
dependsontheelevationwherethewaterheaterisinstalled,and100ft.(30.5m)for4”venting
(deducting5ft.(1.5m)foreachelbowused intheventing system).Donotusemorethan5
elbows. See the table below.
• Whenthehorizontalventrunexceeds5ft.(1.5m),supporttheventrunat3ft.(0.9m)intervals
with overhead hangers.
Installaon
Installaon Manual
Item Material United States Canada
Exhaust pipe and
Fittings
Schedule 40 PVC ANSI/ASTMD1785
ULCS636Certified
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
NOTE: Do NOT Use Cellular Foam Core Pipe
Diameter Max. No. of Elbows Max. Vertical and Horizontal (Total) Vent Length
3in.(76mm) 5 70ft.(21.3m)
4in.(102mm) 5 100ft.(30.5m)
*For each elbow added, deduct 5 ft. (1.5 m) from max. vent length.
No. of Elbows
Max. Vertical or Horizontal (Total) Vent Length
3" venting 4" venting
Up to 3,000 ft Up to 6,000 ft Up to 10,100 ft Up to 10,100 ft
070ft.(21.3m) 40ft.(12.2m) 25ft.(7.6m) 100ft.(30.5m)
1 65ft.(19.8m) 35ft.(10.7m) 20ft.(6.1m) 95ft.(29.0m)
260ft.(18.3m) 30ft.(9.1m) 15ft.(4.6m) 90ft.(27.4m)
355ft.(16.8m) 25ft.(7.6m) 10ft.(3.0m) 85ft.(25.9m)
450ft.(15.2m) 20ft.(6.1m) N/A 80ft.(24.4m)
5 45ft.(13.7m) N/A N/A 75ft.(22.9m)
Excludes vent terminators, termination elbows, or rain caps.
Fordetailsontheventconnection,refertop.16andp.17.

16 Page
-Two-pipe, direct-vent illustraons-
For details of the optional items, refer to the Installation manual for each optional item.
<How to install intake and exhaust venting (two-pipe, direct-vent) with the indoor models>
3" vent connecon
From 3" to 4" vent connecon
Installaon
Installaon Manual
3” coupling
Exhaust vent collar
(Female)
3” straight pipe
3” coupling
Intake vent collar
(Female)
3” straight pipe
1. Connect3"couplingsdirectlyonthe
exhaust and intake vent collar
of the water heater.
2. Connect3”straightpipestothe
couplings.
1. Connect3"x4"increasers
directly on the exhaust and intake
vent collar of the water heater.
2. Connect4”straightpipesto
the increasers.
4” straight pipe
3"x4" increaser
Exhaust vent collar
(Female)
Intake vent collar
(Female)
4” straight pipe
3"x4" increaser
Typical installaons using PVC, ABS, or polypropylene vent
Vercal Installaon
Roof
ashing
Roof
Fire stop
Horizontal Installaon
Wall
Connect between exhaust vent collar and piping.
Seetheinstruconsbelow.
Hanger
Hanger

17 Page
-Single pipe with room-air intake illustraons-
For details of the optional items, refer to the Installation manual for each Optional item.
<How to install single vent with the indoor models>
3" vent connecon
From 3" to 4" vent connecon
Installaon
Installaon Manual
1. Connecta3"elbowdirectly
on the intake vent collar of the
water heater.
2. Connecta3"coupling directly
on the exhaust vent collar of the
water heater.
3. Connecta3”straightpipeto
the coupling.
Typical installaons using PVC, ABS, or polypropylene vent
1. Connecta3"elbowdirectly
on the intake vent collar of the
water heater.
2. Connecta3"x4"increaser directly
on the exhaust vent collar of the
water heater.
3. Connecta4”straightpipetothe
increaser.
3” coupling
3” straight pipe
Exhaust vent collar
(Female)
3” elbow with
bird screen
Intake vent collar
(Female)
4” straight pipe
3"x4" increaser
Exhaust vent collar
(Female)
3” elbow with
bird screen
Intake vent collar
(Female)
Horizontal Installaon Vercal Installaon
Roof
Fire stop
Connect between exhaust vent collar and piping.
Seetheinstruconsbelow.
Roof
ashing
Elbow
Elbow
Wall
Hanger

18 Page
-Exhaust vent (Stainless steel vent)-
This is a Category IV appliance and must be vented accordingly. The vent system must be sealed airtight.
All seams and joints without gaskets must be sealed with high heat resistant silicone sealant or UL listed
aluminumadhesivetapehavingaminimumtemperatureratingof160°F.Forbestresults,aventsystem
should be as short and straight as possible.
• The Indoor models are a Category IV appliance and must be vented accordingly with any 4” vent
approved for use with Category III/IV or Special BH type gas vent.
• The manufacturer recommends the NovaVent line. However, the following are also UL listed
manufacturers: ProTech Systems Inc. (FasNSeal), Metal-Fab Inc., and Heat-Fab Inc. (Saf-T Vent).
• Follow the vent pipe manufacturer’s instructions when installing the vent pipe.
• Themaximumlengthofexhaustventpipingmustnotexceed100ft.(30.5m)(deducting5ft.(1.5
m)foreachelbowusedintheventingsystem).Donotusemorethan5elbows.
• Whenthehorizontalventrunexceeds5ft.(1.5m),supporttheventrunat3ft.(0.9m)intervals
with overhead hangers.
Installaon
Installaon Manual
Diameter Max. No. ofElbows Max. Vertical and Horizontal (Total) Vent Length
4in.(102mm) 5 100ft.(30.5m)
*For each elbow added, deduct 5 ft. (1.5 m) from max. vent length.
Excludes vent terminators, termination elbows, or rain caps.
No. of Elbows Max. Vertical or Horizontal Vent Length
0100ft.(30.5m)
1 95ft.(29.0m)
290ft.(27.4m)
385ft.(25.9m)
480ft.(24.4m)
5 75ft.(22.9m)

19 Page
-Direct-vent and single vent Illustraons-
<How to install stainless steel vent with the indoor models>
• Regarding the clearances from the exhaust terminal to the air inlet or opening, refer to p. 22
to 24.
• Follow all vent system manufacturer’s instructions and all local codes.
• Use 4” Category III/IV approved or Special BH, single or double wall stainless steel vent pipe.
Vercal Installaon
Roof
Roofashing
Fire stop
Rain cap
4" vent connecon for direct-vent installaon
4” stainless steel
vent straight pipe
Exhaust vent collar
of the Indoor models
(Female)
Intake vent collar
(Female)
4” stainless
steel vent
straight pipe
Installaon
Installaon Manual
Typical installaons using stainless steel vents
Exhaust vent collar
of the Indoor models
(Female)
4” stainless steel
vent straight pipe
Intake vent collar
(Female)
4” elbow with
bird screen
1. Connecta4"stainlesssteelvent
straight pipes directly on the
exhaust vent collar of the
water heater.
2. Connecta4"elbowdirectly
on the intake vent collar of the
water heater.
1. Connect4"stainlesssteelvent
straight pipes directly on the
exhaust/intake vent collar of the
water heater.
4" vent connecon for single vent installaon
• The diagram above shows direct-vent installations. For single vent installation, connect a 4" elbow
directly on the intake vent collar instead of a straight pipe. See the instructions below for the detail.
• For details of the optional items, refer to the Installation manual for each Optional item.
Horizontal Installaon
Wall
Sidewall vent
terminaon
Hanger
Hanger

20 Page
-Common-venng system-
The Indoor models can be vented together using the same exhaust and intake venting.
• Upto8waterheaterscanbecommon-ventedtogether.
• Anon-returnvalve(PartNo.9008847005)mustbeusedforeachwaterheaterthatispartofthesystem.
• The water heaters must all be direct-vented.
• For common-venting pieces and components, the manufacturer recommends
Centrotherm's vent line.
Typical common-vent installaon examples
Only the models listed in the table above can be common-vented together.
Different models cannot be common-vented.
CAUTION
Allowable models for common-venting
240 Indoor (T-H3J-DV)
340 Indoor (T-H3S-DV)
540Indoor(T-H3-DV)
For details on the installation of a common-vent system, please refer to the vent manufacturer's
instructions.
Installaon
Installaon Manual
Intake
wall
Exhaust
Roof
Condensate drain port
Non-Return Valve
Exhaust
wall
Roof
Intake
Non-Return Valve
Condensate drain port
Exhaust
Intake
wall
Roof
Non-Return Valve
Condensate drain port