Harman HydroFlex 60 Pellet Boiler - Installation With A Hot Air System; Electrical interconnection of the HF60 to an existing heat pump, or fuel-fired hot air furnace:

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3-90-233R24_11/13
Installation With A Hot Air System
Electrical interconnection of the HF60 to an existing heat pump, or fuel-red hot air furnace:
Interconnectionwithaheatpumpwillgenerallyrequireasecondthermostattobeinstalled.Itisrecommendedthatanew
electronicthermostatbeinstalledasclosetotheexistingthermostataspossible.Installingwithinonefootoftheexisting
thermostatisrecommendedforeaseofinterconnectionandsimilartemperaturesensingability.
Ifprogrammabilityisdesired,boththermostatsshouldhavethiscapability.Ifonlythenewthermostatisprogrammable,you’ll
needtokeeptheexistingthermostatsetseveraldegreesbelowthelowestprogrammedtemperaturesettingofthenew
thermostat.NOTE:Inthisconguration,iftheHF60cannotmaintainthedesiredthermostatsetting,theroomwillbeallowed
tocooltothelowersetpointoftheexistingthermostatbeforeallowingtheheatpumptooperate.
Specialnote:Eveniftheheatpumphasamulti-stagethermostat,itcannotbere-wiredtomaketherststagecontrolthe
HF60,andthesecondstagecontroltheheatpump.Allmulti-stageheatpumpthermostatsareinterconnectedsothatthe
compressorunitand/orthechangeoversolenoidactivatewiththerststageonly.
Controlling the existing furnace fan during overheat situation.
Followingthewiringdiagramonthenextpage,youwillneedtosupplyandinstallapieceof18/3Thermostatwirebetween
thelow-voltagecontrolterminalstripontheupperleft-handsideoftheHF60’scontrolcover,tothelow-voltagecontrolof
theexistingfurnace.
Note: Some systems may have external terminals and some may have them enclosed within the unit. If the connections
to the existing system need to be made internally, be sure to use the proper protective grommet or connector where
passing through the cabinet of the existing unit.
Ifthewiringuseddoesnotmatchthecoloringslisted,followthecorrespondingnumbersontheterminalstripstoensure
proper connection.
Step1. Disconnectelectricalpowertotheexistingheatingsystem.
Step2. Installtheabovementionedthermostatwirebetweenthetwosystems
Step3. Connectthethree(3)wirestotheHF60controlterminalstripasindicated.
Step4. Removethegreenwirewhichcomesfromtheexistingthermostatandconnectstotheterminalmarked“G”onthe
existingsystemandspliceittothegreen(or#1)wirefromtheHF60.
Step5. Connectthewhitewire(or#5)fromtheHF60tothe“G”terminaloftheexistingsystem.Thiswhitewireshouldbe
theonlywireconnectedto“G”.
Step6. Now,thered(#3)wirefromtheHF60shouldbeaddedtothe“R”terminaloftheexistingsystem.Donotremoveor
replaceanyexistingwiresfrom“R”,justaddthisonetothem.
Restorepowertotheexistingsystemonly.Usingtheexistingthermostat,increasethesettingtoverifythatthesystemworks
asitdidpriortotheinterconnection.Increaseanddecreasethethermostatafewtimestoverifyproperreaction.Inthecase
ofaheatpumpsystem,besuretheoutdoorcompressorunitisalsocycling.Notice:Mostcompressorshaveabuiltinlockout
timer(usually5minutes)soyoumayneedtowaitbetweenthermostatadjustmentstoverifyproperoperation.
Onceyouarecertainthatnothingchangedwiththeoperationoftheexistingsystem,turntheexistingsystem’sthermostat
downfarenoughthatitwon’tcomeonduringthetest.ConnectpowertotheHF60,andturnonthecircuitbreakeronthe
frontoftheunit.Withthecontrolinthe“OFF”position,turnthefeedadjusterknobto“Test”.WhentheOVERHEATSAFETY
ZONElightilluminates,thefanontheexistingsystemshouldcomeon.Besurethatthefanistheonlythingon.Thereshould
benopowertothecompressorortheoilorgasburner.