Installation Manual

ManualsBrandsTakagi ManualsCooling & Air QualityT-H2-DV Tankless Water Heater, Direct Vent (Propane)

NormalOperation

39│Page

Onlypipeswithinthewaterheaterareprotectedbythefreezeprotection

system.Anywaterpipes(hotorcold)locatedoutsidetheunitwillnotbe

protected.Properlyprotectandinsulatethesepipesfromfreezing.

HouseholdFlowRates

TakenfromUPC2006



FLOW

• TheflowratethroughtheT‐H2‐DV/T‐H2‐OSislimitedtoamaximumof9.0GPM.

• Thetemperaturesetting,alongwiththesupplytemperatureofthewaterwilldeterminetheflow

rateoutputoftheunit.

• Pleaserefertothetemperaturevs.gallonsperminutechart

onp.50todeterminethelikelyflow

ratesbasedonyourlocalgroundwatertemperatureandyourdesi redoutletwatertemperature

combination.

• BasedontheUnitedStatesDepartmentofEnergy

methodoftestingwaterheateroutput,theT‐H2‐DV/T‐

H2‐OSisratedfor285gallonsper

hour(GPH)or4.8

gallonsperminute(GPM)forNaturalGas,and285GPH

or4.8GPMforLiquidPropane,whenraisingthewater

temperatureby77°F(from58°Fto135°F).

• Refertothecharttotheri ghtfortypicalhousehold

plumbingfixtureflowratestodetermine

whattheT‐H2‐

DV/T‐H2‐OScandoinahouseholdapplication.



FREEZEPROTECTIONSYSTEM

• Thisunitcomesequippedwithheatingblockstoprotectitagainstdamagesasso ciatedwithfreezing.

• Forthisfreezeprotectionsystemtooperatetherehastobeelectricalpowertotheunit.Damageto

the heat exchanger caused by freezing temperatures due to po wer loss is not covered under the



warranty.Incaseswherepowerlossescanoccur,considertheuseofabackuppowersupply.

• Thefreezeprotectionsystemwill activatewhenthesurrounding and/or outside temperaturesdrop

below36.5°F(2.5°C).

• Inanyareassubjecttofreezingtemperatures,TAKAGIhighlyrecommendsanindoorinstallationwith

theT‐

H2‐DVmodel.Insuchaninstallation,freezing issuescanonlyoccur ifcoldairentersthrough

theventingintotheheatexchanger,whetherbynegativepressureswithintheinstallationlocationor

by strong outside winds.It is the installer’s responsibility to be aware of these issues and take all

preventative

measures.TAKAGIwillnotbe responsible  foranydamageto theheatexchangerasa

resultoffreezing.

• TAKAGIalsohighlyrecommendstheuseofabackflowventdampertominimizetheamountofcold

airenteringthroughtheexhaustventingwhenthewaterheaterisoff.

•

Ifyouwillnotbeusingyourheaterforalongperiodoftime:

1. Completelydraintheunitofwater.Refertop.40.

2. Disconnectpowertoyourheater.

Thiswillkeepyourunitfromfreezingandbeingdamaged.



Appliance/Use FlowRate(GPM)

LavatoryFaucet 1.0

BathTub 4.0–10.0

Shower 2.0

KitchenSink 1.5

Dishwasher 1.5

Washingmachine 4.0

CAUTION