Takagi T?H2?DV User manual


TH2DV/TH2OS
OnDemandCondensingWaterHeater
InstallationManualandOwner’sGuide

FEATURING
xENDLESSHOTWATER
xONDEMANDUSAGE
xCOMPACT,SPACESAVING
xENERGYCONSERVATION
xCOMPUTERIZEDSAFETY
xNOPILOTLIGHT
xEASYLINKSYSTEM
WARNING
WARNING
GasTanklessWaterHeater
ModelTH2DVandTH2OS
Suitableforpotablewaterheatingandspaceheating 
TAKAGIIndustrialCo.USA,Inc.
5Whatney
Irvine,CA92618
TollFree:(888)8825244USA
TollFree:(877)8774953CANADA



This product must be installed and
serviced by a licensed plumber, a
licensedgasfitter,oraprofessional
service technician. Improper
installation and/or operation, or
installation by an unqualified
person,willvoidthewarranty.
Iftheinformationinthismanualis
notfollowedexactly,afireor
explosionmayresult,causing
propertydamage,personalinjury,or
death.

Contents
2Page
CONTENTS SPECIFICATIONS
TH2DVandTH2OS
NaturalGasInput
(OperatingRange)
Min:13,000Btu/h
Max:199,000Btu/h
LPGInput
(OperatingRange)
Min:13,000Btu/h
Max:199,000Btu/h
GasConnection ¾”NPT
WaterConnections ¾”NPT
CondensateDrainPort
Connection ½”NPT
WaterPressure 15150psi*
NaturalGasPressure
Inlet
Min.5.0”WC
Max.10.5”WC
LPGas
PressureInlet
Min.8.0”WC
Max.14.0”WC
ManifoldPressureof
theTH2DVNatural:3.2”WC
Propane:5.5”WC
ManifoldPressureof
theTH2OS
Natural:2.7”WC
Propane:4.6”WC
Weight 73lbs.(TH2DV)
70lbs.(TH2OS)
Dimensions H25.6”xW18.5”xD12.4”
Ignition ElectricIgnition
Electric
Supply 120VAC(60Hz)
Consumption
Operationof
theTH2DV
152W
(1.27A)
Operationof
theTH2OS
102W
(0.85A)
Standby 8.2W
(0.07A)
Freeze
Protection
207W
(1.73A)

SPECIFICATIONS………………………………...
INTRODUCTION……………………………….…
SAFETYGUIDELINES…………….……………..
INSTALLATION………………………………..….
General………………………………………..…
IncludedAccessories…………………..…
Optionalitems…………………………..…..
WarningforInstallations………..….....
Highaltituderegionsupportfunctions…
TH2OSInstallation…………………….…
TH2DVInstallation………..…………..…
VentingInstructions……………………....
GasSupply/GasPipeSizing………...…
WaterConnections……………..……….…
PressureReliefValve………………………
Condensatedrain…………………………..
ElectricalConnections…………….........
RemoteControllerConnection…….…
PumpControlConnection………..…….
PumpControlMode…………………….…
EasyLinkSystem…………………………....
APPLICATIONS...…………………………………
SpaceHeating……….………….……………
INITIALOPERATION..…………………….……


OPERATINGSAFETY……………………………
NORMALOPERATION…………………………
General………..……….………….……………
Temperaturesettings.…….…..…………
Flow……………………………………………….
FreezeProtectionSystem…….…………
MaintenanceandService………………
UnitDrainingandFilterCleaning……
TROUBLESHOOTING……..……………………
General………..……….………….……………
Errorcodes.…………………….…..…………
COMPONENTSDIAGRAM………………..…
PARTSLIST………………….………………………
OUTPUTTEMPERATURECHART……...…
PRODUCTREGISTORATIONAND
LIMITEDWARRANTY…………………….……
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51
Takagi reservestherighttodiscontinue,orchange
atanytime,specificationsordesignswithout
noticeandwithoutincurringobligations.
*40psioraboveisrecommendedformaximumflow
NOTE
*Checktheratingplatetoensurethisproduct
matchesyourspecifications.
*InaccordancewithANZIZ21.10.3andSCAQMD
Rule1146.2,COemissiondoesnotexceed400
PPMfornormalinput
InstallationManual
Owne
r
’sGuide

Introduction
3Page
INTRODUCTION
*Thisdiagram
illustratesTakagi’s
tanklesswaterheater
designconceptsonly
anddoesnot
accuratelyrepresent
totheTH2DV/TH2
OS’sphysical
description.
xThis manual provides information necessary for the installation, operation, and
maintenanceoftheTH2DV/TH2OSwaterheater.
xThemodeldescriptionislistedontheratingplatewhichisattachedtothesidepanelof
thewaterheater.
xPleasereadallinstallationinstructionscompletelybeforeinstallingthisproduct.
xIfyouhaveanyproblemsorquestionsregardingthisequipment,consultwithTakagior
itslocalrepresentative.
xTheTH2DV/TH2OSWaterHeaterisanondemand,tanklesswaterheaterdesigned
toefficientlysupplyendlesshotwaterforyourneeds.
xTheprinciplebehindtheTH2DV/TH2OSWaterHeaterissimple:














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automaticallyignitestheburner.
5. Watercirculatesthroughtheheatexchangerandthengetshot.
6. Thecomputerwillmodulatethegassupplyvalveandwaterflowtoproducetheright
amountofhotwateratthecorrecttemperature.
7.
When

the

tap

is

turned

off,

the

unit

shuts

down.
xThe TH2DV/TH2OS are high efficiency models with an inbuild secondary heat
exchangerthatabsorbslatentheatfromtheexhaustgas.
Burner
Condensate
drainport
Secondaryheatexchanger
Thermistor
Thermistor
GasValve
Flowsensor
Watercontrolvalve
B
yp
assvalve
Intake
p
ort Exhaust
Fanmotor
Primaryheat
exchanger
Thermistor
PCB
HotWaterOutlet ColdWaterOutlet
Gas

SafetyGuidelines
4Page

x
xWatertemperaturesover125°Fcancausesevereburnsinstantlyordeathfromscalding.The
watertemperatureissetat120°F(49°C)fromthefactorytominimizeanyscaldingrisk.Before
bathingorshoweringalwayscheckthewatertemperature.
xDonotstoreorusegasolineorotherflammables,vapors,orliquidsinthevicinity
ofthisappliance.
xDo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.19when
installingyourwaterheater:
xDo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.
xDonotdisconnecttheelectricalsupplyiftheambienttemperaturewilldrop
belowfreezing.TheFreezePrevention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PreventionSystemonp.39formore
information.
SAFETYGUIDELINES

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CanadaElectrical
CodePart1inCanada.
3. CarefullyplanwhereyouintendtoinstallyourTH2DV/TH2OSWaterHeater.Pleaseensure:
xYour water heater will have enough combustible air and proper
ventilation.
xLocate your heater where water leakage will not damage
surroundingareas(pleaserefertop.5).
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TAKAGI.
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.


Prohibited
WARNING
RATINGPLATE

Installation
5Page
xInstallation and service must be performed by a qualified installer (for
example,alicensedplumberorgasfitter),otherwisethewarrantybyTakagi
willbevoid.
xTheinstaller(licensedprofessional)isresponsibleforthecorrectinstallation
ofyourTH2DV/TH2OSWaterHeaterandforcompliancewithallnational,
state
/p
rovincial
,
andlocalcodes.
xThewarrantywillnotcoverdamagecausedbywaterquality.
x
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.
x
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.
x
WaterpHlevelsmustbebetween6.5and8.5
x
Wellwatermustbetreated.
xAlthough the TH2DV/TH2OS is designed to operate with minimal sound,
TAKAGI 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.
xLocate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.Takagi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.
xTH2DV/TH2OS are high efficiency products that create condensation. A
condensation drain tube must be installed with the TH2DV/TH2OS to
dischargecondensateintoadrainoutlet.Formoreinformation,refertop.20.
xTAKAGIdoesnotrecommendinstallingtheTH2DVinanatticduetosafety
issues.IfyouinstallyourTH2DVinanattic:
xMake sure your unit will have enough combustion air and proper
ventilation.
xKeeptheareaaroundyourTH2DVclean.Whendustcollectsontheflame
sensor,thewaterheaterwillshutdownonerrors.
xLocateunitforeasyaccessforserviceandmaintenance.
xA drain pan, or other means of protection against water damage, is
requiredtobeinstalledunderthewaterheaterincaseofleaks.
INSTALLATION


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atthebeginningofthismanual.



WARNING
WARNING
CAUTION
PLEASEREADTHISMANUALCAREFULLYANDFOLLOWALLDIRECTIONS.

Installation
6Page

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. Themanifoldgaspressureispresetatthefactory.Itiscomputercontrolledandshouldnot
needadjustment.

3. Maintainproperspaceforservicing.Installtheunitsothatitcanbeconnectedorremoved
easily.Refertop.8,p.9andp.10forproperclearances.

4. Theelectricalconnectionrequiresameansofdisconnection,toterminatepowertothewater
heaterforservicingandsafetypurposes.

5. Ifyouwillbeinstallingtheunitinacontaminatedareawithahighlevelofdust,sand,flour,
aerosolsorothercontaminants/chemicals,theycanbecomeairborneandenterandbuildup
withinthefanandburnercausingdamagetotheunit.

6. Particles from flour, aerosols, and other contaminants may clog the air vent or reduce the
functionsoftherotatingfanandcauseimproperburningofthegas.Regularlyensurethatthe
area around the unit is dust or debrisfree; regular maintenance is recommended for these
typesofenvironment.

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.15).
INCLUDEDACCESSORIES

Checkthattheinstallationmanual,thecommunicationcable,thewarrantycardandtheTHPA01PVC
adaptorareincludedwiththeunit(theadaptorcomeswiththeTH2DVmodelonly).
Fordetailsonhowtoconnecttheadaptor,refertoP.14.
1.Manual


2.Communicationcable

3.WarrantyCard

4.THPA01PVCadaptor
(TH2DVmodelonly)

Q
t
y
:1
Qty:1
Q
t
y
:1
Qty:1

Installation
7Page

OPTIONALITEMS
1.TMRE30TemperatureRemoteController
The TMRE30 Temperature Remote Controller has two functions.
ItallowstheoutputtemperaturefromtheTH2DV/TH2OS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. 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,170°F,175°F,180°Fand185°F.
Seethetroubleshootingsectionforinformationonpossibleerror
codes.
2.THPC02Pipecover
TheTHPC02PipecoverprotectstheplumbingpipestotheTH2
DV/TH2OSfromunexpectedadjustments.Thispipecoveris
fixedtothebottomoftheTH2DV/TH2OS,whichhidesthe
plumbingandimprovesthevisualaspectsofthewholeinstallation
forthewaterheater.
3.TKKPWL4andTKKPWH4TVentWallthimblewithTermination

Theseterminationsareusedwhenventingoutthroughthewalland
arecompatiblewiththeTVentpipesystem.
Theseterminationsarespecialstainlesssteelventsforgasappliances
andareULlistedasCategoryII,IIIandIV.Therearetwotypesof
terminations:theLouverterminationandtheHoodtermination.For
differentwallthicknesses,thereare3rangesoflengthsavailable
(refertotheTVentbrochurefordetails).
Installtheseventterminationsinaccordancewiththeirinstallation
instructionsandanyapplicablelocalcodes.
4.THNT01Neutralizerkit

TheTHNT01Neutralizerassemblyneutralizesthecondensate
(acidicwater)thatformsinthesecondaryheatexchangerofthe
TH2DV/TH2OS.
ItconnectstothecondensatedrainportoftheTH2DV/TH2OS
byusingconnectorsincludedwiththeneutralizerkit.Refertop.
21forthedetails.


TKKPWL4

Louver
Termination
TKKPWH4

Hood
Termination

Installation
8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feetfromitstoporeaves.
Theareaunderanoverhangmustbeopento
threesides.(TH2OSonly)

Do not install the water heater vent terminator
within1ft.intheUSAofanyairintakeorbuilding
opening, and with in 3 ft. in Canada of any air
intakeorbuildingopening.(TH2OSonly)(Refer
top.15)

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.
Prohibited Prohibited
FORYOURSAFETY,READBEFOREINSTALLATION:

Installation
9Page
Thedarksquaresindicatethedirectionthe
dipswitchesshouldbesetto.
Leftbankofdipswitches
Leftbankofdipswitches
xThere is a 3” clearance from
the left and right sides of the
unit to combustible and non
combustible
surfaces. However, if any
portion or area of the surface
is exposed to the exhaust
fumes(i.e.directlytothesides
of the vent cap), that surface
mustbeatleast24”away.
xKeeptheclearances.
2,500 to4,000 ft 4,000to5,000ft
Altitude

HIGHALTITUDEINSTALLATIONS

Checktheelevationwhereyourwaterheaterisinstalled.Setdipswitchesshowninthetablebelow
dependingonthealtitude.Thesedipswitches(No.5andNo.6)areonthecomputerboardontheleft
bankonly.


 0to2,500ft
(DEFAULT)

Over5,000ft
SwitchNo.5 OFF ON OFF
Consult
TAKAGI
Technical
Dept.
at1888
8825244
SwitchNo.6 OFF OFF ON

TH2OSINSTALLATION
1. InstalltheTH2OSonlyinareaswithmild,temperateclimates.
2. The TH2OS shall be wallmounted or mounted on a stand. Locate the TH2OS in an open,
unroofedareaandmaintainthefollowingminimumclearances:







DONOTadjustanydipswitchesontherightbank.
ࣰࣱࣲ࣭࣮࣯ࣳࣴ
 
࣭ࣵ࣬
 
ࣰࣱࣲ࣭࣮࣯࣭ࣳࣴࣵ࣬
 
ࣰࣱࣲ࣭࣮࣯࣭ࣳࣴࣵ࣬
Side3”
Top36”
Side3”
Front24”
Bottom12”
Back0.5”

Installation
10Page

Improperventingofthisappliancecanresultinexcessivelevelsofcarbonmonoxide
whichcanresultinseverepersonalinjuryordeath.
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.

TH2DVINSTALLATION

TH2DV is 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 PVC
(Plastic)ventingifPVCisused.
If the exhaust gas temperature exceeds 140°F, these components will enable the unit to safely stop
operations.  (For the TH2OS model, these components are not available since there’s no exhaust
ventingrequired.)

xTH2DVrequiresa4”makeupintakeairsupply
pipe.Theintakepipemustbesealedairtight.
xAir supply pipe can be made of ABS, PVC,
galvanized steel, corrugated stainless steel,
orCategorylll/IVstainlesssteel.
xSidewallventingisrecommendedfor
the TH2DV. Vertical venting (roof
termination)isacceptable.
xTAKAGI recommends running the
exhaust vent and the intake pipe as
parallelaspossible.
xTheTHPA01adaptorisusedtomake
theconnectionbetweentheTH2DV
vent collar and PVC vent pipe easier
andformaintenancepurposes.

VENTINGINSTRUCTIONS
General
TheTH2DV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 B159.1 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,TH2DVmayalsobeventedwithplasticpipematerialssuchasPVC.Fordetails,pleaserefer
totheExhaustVent(PVCVent)sectiononp.11.VentinstallationsinCanadawhichutilizeplasticvent
systemsmustuseventingthatcomplieswithULCS636.
WARNING
Top12”
Side3”
Back0.5”
Side3”
Front4”
(24”Recommended
forMaintenance)
Bottom12”
Keeptheclearances.

Installation
11Page
Excludeselbowtermination,raincaps,orthe3”PVCConcentricTermination
FordetailsontheventconnectiontotheTH2DV
,
refertoP.14
*Foreachelbowadded,deduct5ft.frommax.ventlength.

Exhaustvent(PVC&ABSvent)

TheTH2DVcanbeconnectedwithPVCorABSventing(temperatureratedupto149°F).However,
TAKAGIrecommendsPVC(orABS)ventingcertifiedtoULCS636standards.
Item Material UnitedStates Canada
Exhaustpipe&
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
PipeCement/Primer
PVC ANSI/ASTMD2564
CPVC ANSI/ASTMF493
ABS ANSI/ASTMD2235
NOTE:DoNOTUseCellularFoamCorePipe
xThemaximumlengthofexhaustventpipingmustnotexceed50ft.for4”ventingand25ft.for
3”venting(deducting5ft.foreachelbowusedintheventingsystem).Donotusemorethan5
elbowsfor4”ventingand2elbowsfor3”venting.
xWhenthehorizontalventrunexceeds5ft.,supporttheventrunat3ft.intervalswithoverhead
hangers.

Diameter Max.No.ofElbow Max.Vertical&Horizontal(Total)VentLength
3” 2 25ft.
4” 5 50ft.

No.ofElbows Max.VerticalorHorizontalLength
3”venting 4”venting
0 25ft. 50ft.
1 20ft. 45ft.
2 15ft. 40ft.
5 N/A 25ft.








This is a Category IV appliance and must be vented accordingly. The vent system must be sealed air
tight.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.
xThe TH2DV is 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.
xTAKAGI recommends the “TVent” line manufactured by TAKAGI (Refer to Takagi’s “TVent”
brochurefordetails).However,thefollowingarealsoULlistedmanufacturers:ProTechSystems
Inc.(FasNSeal),FlexLInc.,ZFlexInc.(ZVentIII),MetalFabInc.,andHeatFabInc.(SafTVent).
xFollowtheventpipemanufacturer’sinstructionswheninstallingtheventpipe.
Exhaustvent(Stainlesssteelvent)

Installation
12Page
Improperinstallationcancausenauseaorasphyxiation,severeinjuryordeathfrom
carbonmonoxideandfluegasespoisoning.Improperinstallationwillvoidproduct
warranty.
xDonotcommonventthisappliance withanyotherventedappliance(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CategoryIII/IVapprovedorSpecialBHventpipe).
xThe maximum length of exhaust vent pipingmust not exceed 50 ft. (deducting 5 ft. for each
elbowusedintheventingsystem).Donotusemorethan5elbows.
xWhenthehorizontalventrunexceeds5ft.,supporttheventrunat3ft.intervalswithoverhead
hangars.

Diameter Max.No.ofElbow Max.Vertical&Horizontal(Total)VentLength
4” 5 50ft.

*Foreachelbowadded,deduct5ft.frommax.Ventlength.
No.ofElbows Max.VerticalorHorizontalLength
0 50ft.
1 45ft.
2 40ft.
5 25ft.


Venttermination

xTheventterminatorprovidesameansofinstallingventpipethroughthebuildingwallandmustbe
located in accordance with ANSI Z223.1/NFPA 54, or in Canada with CAN/CSAB149.1 and local
applicablecodes.
xApropersidewalldirectventterminatorisrecommendedwhenthewaterheaterisventedthrougha
sidewall.

GeneralrulesforventingtheTH2DVwaterheaterare:
1. Placethewaterheaterascloseaspossibletotheventterminator.
2. TheventcollarofthewaterheatermustbefasteneddirectlytoanunobstructedventpipeorTH
PA01adaptor.
3. Donotweldtheventpipetothewaterheatercollar.
4. Donotcuttheventcollaroftheunit.
5. Theweightoftheventstackmustnotrestonthewaterheater.
6. The vent must be easily removable from the top of the water heater for normal service and
inspectionoftheunit.
7. Thewaterheaterventmustnotbeconnectedtoanyothergasapplianceorventstack.
8. Avoidlocatingthewaterheaterventterminator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.
9. Avoidusinganoversizedventpipeorusingextremelylongrunsofthepipe.
10. Locatethevent terminator so that it cannot be blocked by any debris, at any time. Most codes
requirethattheterminatorbeatleast12inchesabovegrade,buttheinstallermaydetermineifit
shouldbehigherdependingonthejobsiteconditionandapplicablecodes.
11. Forrooftopventing,araincaporotherformofterminationthatpreventsrainwaterfromentering
intothewaterheatermustbeinstalled.
WARNING

Installation
13Page
1. ConnecttheTHPA01PVCadaptor*directlyontheexhaustventcollaroftheTH2DV.
2. Connecta4”PVCcoupler(or4x3”PVCreducer)totheTHPA01PVCadaptor.
3. Fromthecoupler(orreducer),continueontherestoftheventrunwith4”PVCpipe(or3”PVC
pipe.)
(ForExhaust)

HorizontalInstallationDiagram
(Withelbowterminations)
HorizontalInstallationDiagram
(With3”PVCConcentricTermination)
Keepa1”clearancebetweenwall
andtheintakesectionofthe
concentrictermination.Seethe
diagramtotheleft.
PVCVentingIllustrations
HowtoinstallPVCventingwiththeTH2DV
ConnectionbetweenexhaustventcollarandPVCpiping
Seethenextpageforinstructions.
Wall
ConnectionbetweenexhaustventcollarandPVCpiping
Seethenextpageforinstructions.
Wall
1” minimum
clearance
ConcentricTermination
Insertthebirdscreenincludedwith
thetermination
VerticalInstallationDiagram
Roof
RoofFlashing
Firestop

Installation
14Page
1. Connecta4”PVCStraightpipedirectlyontheintakeventcollaroftheTH2DV.
2. Connecta4x3”PVCreducertothe4”PVCStraightpipe.
3. Fromthereducer,continueontherestoftheventrunwith3”PVCpipe.
(ForIntake:4”only)
(ForIntake:3”only)


xRegardingtheclearancesfromtheexhaustterminatortothe
airinletoropening,refertothenextfewpages.
xFollow all vent system manufacturer’s instructions and all
localcodes.
xDo not common vent or connect any vent from other
appliancestotheTH2DVvent.
xUse 4” Category III/IV approved or Special BH, single or
doublewallstainlesssteelventpipe.
VerticalInstallationDiagram
HorizontalInstallationDiagram
*THPA01PVCadaptorisincludedwiththeTH2DV.
4”ventconnectionDiagram 3”ventconnectionDiagram
Stainlessstee
l
Venting
I
llustrations
1.Connecta4”PVCStraightpipedirectlyontheintakeventcollaroftheTH2DV.
3”PVCStraightpipe
4x3”PVCreducer
THPA01PVCadaptor*
Exhaustventcollarof
theTH2DV(Female)

3”PVCStraight
pipe
4x3”PVCreducer
4”PVCStraight
pipe
Intakeventcollar
Exhaustventcollarof
theTH2DV(Female)

THPA01PVCadaptor*
4”PVCcoupler
4”PVCStraightpipe
4”PVCStraight
pipe
Intakeventcollar

RoofFlashing
Roof
RainCap
Firestop
Wall
SidewallVent
Terminator

Installation
15Page

Ventclearances

Canada U.S.A
Directventand
otherthanDirect
Vent
Directvent OtherthanDirectVent
A Clearanceabovegrade,veranda,porch,deck,
orbalcony. 1foot 1foot 1foot
B Clearancetowindowordoorthatmaybe
opened. 3feet 1foot
4feetfrombeloworside
opening.1footfrom
aboveopening.
C Clearancetopermanentlyclosedwindow * * *
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terminator.
* * *
E Clearancetounventilatedsoffit * * *
F Clearancetooutsidecorner * * *
G Clearancetoinsidecorner * * *
H Clearancetoeachsideofcenterlineextended
abovemeter/regulatorassembly 3feet * *
I Clearancetoserviceregulatorventoutlet. 3feet * *
J
Clearancetononmechanicalairsupplyinlet
tobuildingorthecombustionairinlettoany
otherapplication.
3feet 1foot
4feetfrombeloworside
opening.1footfrom
aboveopening.
K Clearancetomechanicalairsupplyinlet. 6feet 3feet 3feet
L Clearanceabovepavedsidewalkorpaved
drivewaylocatedonpublicproperty. 7feet * 7feet
M Clearanceunderveranda,porchdeck,or
balcony. 1foot * *
*ForclearancesnotspecifiedinANSIZ223.1/NFPA54orCAN/CSAB149.1,pleaseuseclearancesinaccordancewith
localinstallationcodesandtherequirementofthegassupplier.

Installation
16Page
Additionalclearances
Pleasefollowalllocalandnationalcodesinregardstoproperterminationclearances.Intheabsenceof
suchcodes,thefollowingclearancescanbeusedasguidelines.Localcodessupersedetheseguidelines.
Forsidewallterminations

Exhausttermination
1ft.
1ft. 2ft.
Inside
corner
Formultiplesidewallexhaust
terminations(e.g.multiunit
systems),anexhausttermination
mustbeatleast1ft.awayfrom
anotherexhausttermination.An
exhaustterminationmustalsobe
atleast2ft.awayfromaninside
corner(iftheadjacentwallisless
than2ft.oflength,theminimum
requireddistanceawayfromthe
insidecornerwillbeequaltothe
lengthofthatadjacentwall).
Fordirectvent sidewall
terminationsthatusetwo
separatepenetrationsforthe
intakeandexhaust,distance
theintakeandexhaust
terminationsatleast3ft.away
fromeachother,nomatterthe
orientation.
Formultipleunit,directventsidewall
terminationsthatcombinetheintake
andexhaustintoasinglepenetration,
spaceeachdirectventterminationat
least1ft.awayfromeachother,no
mattertheorientation.Adirectvent
terminationmustalsobeatleast2ft.
awayfromaninsidecorner(ifthe
adjacentwallislessthan2ft.of
length,theminimumrequired
distanceawayfromtheinsidecorner
willbeequaltothelengthofthat
adjacentwall).
Formultipleunitrooftopterminations(whetherforstandardindooror
directventinstallations)spaceallexhaustandintaketerminationsin
accordancewithlocalcodes.Anexhaustterminationmustbespacedfrom
awallorsurfaceinaccordancewithlocalcodesaswell.Intheabsenceof
suchacode,anexhaustterminationmustbeahorizontaldistanceofat
least2ft.awayfromawallorsurface.
A:inaccordancewithlocalcodes
Forrooftopterminations
Airintake
Exhaust termination
A
A
A
A
A
2ft.
Airintake
Exhaust
termination
Exhaustand/ordirectvent
sidewallterminationsshould
beatleast2ft.awayfroman
oppositesurface/wall.Do
notplacethetermination
directlyinfrontofan
openingintoabuilding.
2ft.
Exhaust
termination
Airsupplyinlet
3ft.
3ft.
3ft.
Directventtermination
1ft.
1ft.
Inside
corner
2ft.

Installation
17Page



1. Turnoffallelectricpowertothewaterheaterifserviceistobeperformed.
2. Turnthemanualgasvalvelocatedontheoutsideoftheunitclockwise3totheoffposition.
xEnsure that any and all gas regulators used are operating properly and
providinggas pressures withinthespecified rangeshownbelow. Excessgas
inletpressuremaycauseseriousaccidents.
xConversion of this unit from natural gas to propane or vise versa cannot be
doneinthefield.Contactyourlocaldistributortogetthecorrectunitforyour
gas type. Conversion done by anyone other than the manufacturer or Takagi
Service Representative will void all warranty.  Takagi is not liable for any
propertyand/orpersonaldamageresultingfromunauthorizedconversions.

GASSUPPLYANDGASPIPESIZING

*Checkthatthetypeofgasmatchestheratingplatefirst.
1. Theminimumandmaximuminletgaspressuresare:
Gastype Inletgaspressure
NaturalGas Min.5.0”WC–Max.10.5”WC
PropaneGas Min.8.0”WC–Max.14.0”WC
2. Gaspressure belowthisspecified range forthe TH2DV/TH2OS and/orinsufficientgasvolume
willadverselyaffectperformance.ThesepressuresaremeasuredwhentheTH2DV/TH2OSisin
fulloperation.
3. Inletgaspressuremustnotexceedtheabovemaximumvalues;gaspressureabovethespecified
rangewillcausedangerousoperatingconditionsanddamagetotheunit.
4. Until testingofthe main gas linesupplypressure is completed, ensure thegasline to theTH2
DV/TH2OSisdisconnectedtoavoidanydamagetothewaterheater.

Measuringinletgaspressure

TheTH2DV/TH2OScannotperformproperlywithoutsufficientinletgaspressure.Beloware
instructionsonhowtochecktheinletgaspressure.THISISONLYTOBEDONEBYALICENSED
PROFESSIONAL.

1. Shutoffthemanualgasvalveonthesupplygasline.
2. Removethescrewforthepressureportlocatedonthegas
inletoftheTH2DV/TH2OSshowninthediagramtothe
right.
3. Connectthemanometertothepressureport.

WARNING
TOTURNOFFGASTOAPPLIANCE

Installation
18Page
Sizethegaspipeappropriatelytosupplythenecessaryvolumeofgasrequiredforthe
TH2DV/TH2OS(199,000BTU/hforbothNaturalGasandLiquidPropane)using
ANSI233.1/NFPA54intheUSAorCAN/CSAB149.1inCanadaorlocalcodes.
Otherwise,flowcapabilitiesandoutputtemperatureswillbelimited.

4. Reopenthemanualgasvalve.Checktoseethattherearenogasleaks.Opensomeofthefixtures
thatusethehighestflowratetoturnontheTH2DV/TH2OS.
5. Checktheinletgaspressure.WhenTH2DV/TH2OSisonmaximumburn,themanometershould
readfrom5.0”to10.5”WCforNaturalgas,from8.0”to14.0”WCforLiquidPropane.





1. InstallamanualgasshutoffvalvebetweentheTH2DV/TH2OSandthegassupplyline.
2. 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.
3. Alwayspurgethegaslineofanydebrisand/orwaterbeforeconnectingtothegasinlet.

NaturalGasSupplyPiping
MaximumDeliveryCapacityofCubicFeetofGasperHourofIPSPipeCarryingNaturalGasof0.60SpecificGravity
BasedonPressureDropof0.5”WC

BasedonEnergyContentof1000BTU/CubicFt.:TH2DV/TH2OSrequires199CubicFt./hr.
Unit:CubicFeetperHour
PipeSize LengthinFeet
Inches 10’ 20’ 30’ 40’ 50’ 60’ 70’ 80’ 90’ 100’ 125’ 150’ 200’
¾” 363 249 200 171 152 138 127 118 111 104 93 84 72
1” 684 470 377 323 286 259 239 222 208 197 174 158 135
1¼” 1,404 965 775 663 588 532 490 456 428 404 358 324 278
1½” 2,103 1,445 1,161 993 880 798 734 683 641 605 536 486 416
2” 4,050 2,784 2,235 1,913 1,696 1,536 1,413 1,315 1,234 1,165 1,033 936 801
Propane(LP)GasSupplyPiping
MaximumCapacityofPropane(LP)GasBasedon11”WCsupplypressureata0.5”WCpressuredrop
Unit:kBTUperHour
PipeSize LengthinFeet
Inches 10’ 20’ 30’ 40’ 50’ 60’ 70’ 80’ 90’ 100’ 125’ 150’ 200’
¾” 567 393 315 267 237 217 196 185 173 162 146 132 112
1” 1,071 732 590 504 448 409 378 346 322 307 275 252 213
1¼” 2,205 1,496 1,212 1,039 913 834 771 724 677 630 567 511 440
1½” 3,307 2,299 1,858 1,559 1,417 1,275 1,181 1,086 1,023 976 866 787 675
2” 6,221 4,331 3,465 2,992 2,646 2,394 2,205 2,047 1,921 1,811 1,606 1,496 1,260

Formoreinformation,pleaseseethenextpage.


Installation
19Page



Donotusethiswaterheaterifanyparthasbeensubmersedunderwater.Immediatelycalla
licensedprofessionaltoinspectthewaterheaterandtoreplaceanydamagedparts.
WATERCONNECTIONS
1. All pipes, pipe fittings, valves and other components, including soldering materials, must be
suitableforpotablewatersystems.
2. Amanualshutoffvalvemustbeinstalledonthecoldwaterinlettothewaterheaterbetweenthe
mainwatersupplylineandtheTH2DV/TH2OS.
3. Inaddition,amanualshutoffvalveisalsorecommendedonthehotwateroutletoftheunit.Ifthe
TH2DV/TH2OS is installed within, or subjected to, a closed loop water system, a thermal
expansiontankmustbeinstalled.
4. Before installing the water heater, flush the water line to remove all debris, and after
installationiscomplete,purgetheairfromtheline.Failuretodosomaycausedamagetothe
heater.
5. Thereisawiremeshfilterwithinthecoldinlettotrapdebrisfromenteringyourheater.Thiswill
needtobecleanedperiodicallytomaintainoptimumflow.
BasedonEnergyContentof1000BTU/CubicFt:

Divideeachappliance’sBTUrequirementby1000BTUtoget
theappliancesCubicFt.requirement.

Takagiintoaccountthedistancetheapplianceisfromthegas
meter,lookintheabovegascharttoproperlysizetheline.

Forsectionsofthegaslinesupplyinggastomorethanone
appliance(Ex:PointAtoPointB),addupthecubicft.
requirementsoftheappliancesthatarebeingsuppliedbythat
section,andsizetothefarthestappliance.

ForExample:ThesectionfromAtoBsuppliesgastothe
furnace,range,anddryer.AddinguptheBTUrequirements
anddividingby1000yieldsacubicft.requirementof220
cubicft.ofgas.Thefarthestapplianceistherange,whichis50
ft.awayfromthemeter.Lookingattheabovechart,and
underthecolumnof50ft.,SectionAtoBneedstobe1”in
ordertosupply220cubicft.
Donotreversethehot
outletandcoldinlet
connectionstotheTH2
DV/TH2OSWaterHeater.
Thiswillnotproperlyactive
thewaterheater.
FORYOURSAFETY,READBEFOREOPERATING:
10’Length
1”PipeSize C
GasSizingExample
(NaturalGas)
10’Length
3/4”PipeSize
15’Length
1/2”PipeSize
10’Length
1/2”PipeSize
Furnace
120,000BTU
TH2DV/
TH2OS
199,000BTU
5’Length
11/4”PipeSize
Range
65,000BTU
10’Length
3/4”PipeSize
Dryer
35,000BTU
15’Length
1”PipeSize
5’Length
11/4”PipeSize
GasMeter
B
A
CAUTION
Condensate drainport
Wateroutlet
(HOT)
Waterinlet
(COLD)
GAS inlet

Installation
20Page

PRESSURERELIEFVALVE
TheTH2DV/TH2OShasahightemperatureshutoffswitchbuiltinasastandardsafetyfeature(called
aHiLimitswitch)thereforea“pressureonly”reliefvalveisrequired.
1. Thisunitdoesnotcomewithanapprovedpressurereliefvalve.
2. Anapprovedpressurereliefvalvemustbeinstalledonthehotwateroutlet.
3. Thepressurereliefvalvemustconformto
ANSIZ21.22orCAN14.4andinstallation
mustfollowlocalcode.
4. The discharge capacity must be at
least199,000BTU/h.
5. The pressure relief valve needs to be
ratedforamaximumof150psi.
6. Thedischargepipingforthepressurereliefvalvemust
be directed so that the hot water cannot splash on
anyoneoronnearbyequipment.
7. Attach the discharge tube to the pressure relief valve and run the end of the tube to within 6"
from the floor. This discharge tube must allow free and complete drainage without any
restrictions.
8. Ifthepressurereliefvalveinstalledonthe TH2DV/TH2OSdischargesperiodically,thismaybe
duetoadefectivethermalexpansiontankordefectivepressurereliefvalve.
9. Thepressurereliefvalvemustbemanuallyoperatedperiodicallytocheckforcorrectoperation.
CONDENSATEDRAIN
xTheTH2DV/TH2OSdoesnotincludeabuiltincondensateneutralizercartridgeforreducingthe
pHlevelofcondensatewater.Iflocalcodesdictatethatcondensatemustbeneutralizedpriorto
drainage,acondensateneutralizermustbeinstalled.Asanoption,TakagiofferstheTHNT01
Neutralizerassembly(soldseparately).
xIntheabsenceofapplicablelocalcodesandregulations,TAKAGIrecommendsthatcondensatebe
disposedofintoastandarddrain.Connectadraintubefromthecondensatedrainport(shown
below)locatedonthebottomoftheTH2DV/TH2OStoastandarddrain.


Pressure
ReliefValve Hot
outle
t

Cold
inle
t

Gas
AsCloseas
Possible
xFollowallcoderequirements
of the local authority on
condensate neutralizers and
whether or not they are
requiredfortheinstallation.

Condensate drainport