Rheem HTPG EcoNet Series - Page 3

# Remedy
Closedoortothebox.Makesuredoorremainsclosedunless/untilaccesstoboxisneeded.
Verifyatcontrollerdisplaythecurrentsuperheatandvalveposition;goto Status →Superheat/EXVCurrentPos. Ifsuperheatis
consistentlyhighandvalveisconsistentlyrunningatorcloseto100%,thesystemcouldbelowonrefrigerant.Verifyifsight
glassatcondensingunitisclear.Verifysuctionpressurewithasetofgauges.Rechargesystemasneeded,verifyifanyleaksare
presentandfixasneeded.
Verifyatcondensingunitifcompressorisshuttingdownintermittently.Troubleshootcondensingunitandverifyifhighhead
pressure,phaseloss,etc.
Verifyunderthecontrollersettingsthatthecorrectrefrigerantisselected.Onthedisplay,goto
Settings →Equipment→Refrigerant .Anincorrectrefrigerantsettingwillcauseincorrectsuperheatcalculationandthesystem
willnotoperateproperly.
VerifyifSuctionTempThermistoralarmisactive:oncontrollerdisplaygoto Service →CurrentAlarms .AlsoverifySuction
TemperaturereadingunderStatus→Sensors→SuconTemp ;ifitisreading"‐60 ⁰F",thesensorisnotmakinggoodcontactoris
missing.IfSuctionTempsensorinputismissing,theEXVwillremainatafixedpositionuntilsensorisreplaced,andalarm
"A100SuctionTempThermistorFailure" willbeactive.Ifsensorisreadingavalueotherthan‐60 ⁰F,verifythatitisnotan
erraticvalueandthatthereadingreasonablycorrespondstotheconditionsattheevaporator(forexample,ifsensorisreading
150⁰Fwhenthesuctionlineattheevaporatorisnearfreezingconditions). ReplaceSuctionTempThermistor(partno.
08219637).
VerifyifSuctionPressurealarmisactive:oncontrollerdisplaygoto Service →CurrentAlarms .AlsoverifySuctionPressure
readingunderStatus→Sensors→SuconPressure ;ifitisreading"‐14.7PSIG",thesensorismalfunctioningorisdisconnected.
Ifthecontrollerdetectsthatthepressureinputismissing,alarm "A106SuctionPressureSensorFailure" willbeactiveandthe
controllerwillattempttocalculateapproximatesuperheatbyusingEvapTemp1readinginsteadofSaturatedSuctionTempand
continuemeteringtheEXV,butthecalculatedsuperheatwillnotbeasaccurate. ReplaceSuctionPressureTransducer(partno.
08219621).
VerifyharnessconnectiontotheEXVandtothecontrollerboardissecure.SetSystemEnabletoNO,under Settings →System
Enable inordertoclosetheEXVandforceapumpdown.ConfirmthattheEXVcanbeheardmovingasitcloses.ConfirmEXV
positionunderStatus→EXV→EXVCurrentPos. is0%.Verifythatcompressorpumpsdownandshutsoffafteracoupleof
minutes;SuctionPressurereadingunderStatus→Sensors→SuconPressure shoulddecreaseasthesystempumpsdown.If
thecompressorisstillrunninganddoesnotturnoff,theEXVmaybemalfunctioningandallowingsomerefrigeranttopass
throughevenafterbeingcommandedbythecontrollertoclose. See
AddendumAformoreinformationontroubleshootingthe
EXV.ReplaceEXVifnecessary.
Makesuredoortothefreezeriskeptclosedunless/untilaccesstofreezerisneeded.
Verifythatwhencontrollerstartsadefrost,theheatersareenergizedandoperatingproperly.Amanualdefrostcanbestarted
bygoingonthedisplaytoService →DefrostControl→StartaDefrost .VerifyatthecontrollerboardthattheLED'sforthe
defrostrelaysturnONandtheirstatusisONonthedisplay( Status→Outptus→DefrostRelay#1/#2 ).IftheunitisaLow
Profileevaporator,makesurethatCoilTypeissetto"Single" (gotoSettings→Equipment andscrolldowntoverifythese
parameters),andthatEvapTemp1sensorisconnectedandhavingavalidreading.IfEvapTemp1sensorisdisconnected,the
controllerwillalarm( "A101EvaporatorTempSensorFailure" )andtheDefrostRelayswillnotturnON.IfCoilTypeis
mistakenlysettoDual,thecontrollerwillalarm( "A102EvapTemp2ThermistorFailure" )andthemissingEvapTemp2sensor
willpreventDefrostRelay#2fromturningon;thiswouldkeepthebottomheateranddrainpanheaterfromturningonduringa
defrostandwillcauseicebuilduponthebottompartofthecoil.IfbothDefrostRelaysareturningON,verifywithameterthat
theheatersaredrawingampsandarewarmingup;iftheyarenot,verifytheheaterwiringwiththewiringdiagramatthe
evaporator.Iftheheatersarewiredproperlybutstillnotheating,theymayneedtobereplaced.
Iftheheatersareverifiedtobeworkingproperly,proceedtoverifydefrostcycleduration:onthecontrollerdisplay,goto
Status →Defrost→LastDefr.Time .Also,forceadefrostandwaitforittofinishtotakenoteoftheduration.LowProfile
Evaporatorstypicallyneedbetween20to30minutesdefrostdurationtocleartheice.Ifthedefrostcycleistooshort,the
DefrostTerminationTemperature(Def.Term.Temp )andRuntimeUntilDefrost(Def.Cmp.RunTime )canbeadjustedas
neededinSettings→Equipment .Also,thepulsingonDefrostRelay#1(topheater)canbedisabledbysetting DefrostPulse
Override toYESifneeded.Iftheunitalreadyhassomeicebuiltupinthecoil,itmaytakeseveraldefrostcyclestocleartheice
aftertheparametersmentionedaboveareadjusted.
Makesuredoortothefreezeriskeptclosedunless/untilaccesstofreezerisneeded.
Verifythatwhencontrollerstartsadefrost,theheatersareenergizedandoperatingproperly.Amanualdefrostcanbestarted
bygoingonthedisplaytoService →DefrostControl→StartaDefrost .VerifyonthecontrollerboardthattheLED'sforthe
defrostrelaysturnONandtheirstatusisONonthedisplay( Status→Outptus→DefrostRelay#1/#2 ).IftheunitisaCenter
Mountevaporator,makesurethatCoilType issetto"Dual" andDefrostPulseOverride setto"YES" (goto
Settings→Equipment andscrolldowntoverifytheseparameters),andthatEvapTemp1andEvapTemp2sensorsare
connectedandhavingavalidreading.IfEvapTemp1sensorisdisconnected,thecontrollerwillalarm( "A101EvaporatorTemp
SensorFailure" )andDefrostRelay#1willnotturnON;ifEvapTemp2sensorisdisconnected,thecontrollerwilalarm( "A102
EvapTemp2ThermistorFailure" )andDefrostRelay#2willnotturnON.IftheDefrostRelaysareturningON,verifywitha
meterthattheheatersaredrawingampsandarewarmingup;iftheyarenot,verifytheheaterwiringwiththewiringdiagram
attheevaporator.Iftheheatersarewiredproperlybutstillnotheating,theymayneedtobereplaced.
OnCenterMountevaporators(
CoilType=Dual ),bothEvapTemp1(whitewires)andEvapTemp2(bluewires)areusedfor
defrosttermination.Duringadefrostcycle,whenEvapTemp1sensorreachesDefrostTerminationTemp,theDefrostRelay#1
willturnoff.SameforEvapTemp2withDefrostRelay#2;eachsidewillterminatedefrostindependently.Verifywiththe
wiringdiagramontheunitthatEvapTemp1sensorislocatedonthecoilwhoseheatersarewiredtoDefrostRelay#1.Same
goesforEvapTemp2,itshouldbelocatedonthecoilwhoseheatersarewiredtoDefrostRelay#2.
OnCenterMountevaporators(CoilType=Dual ),makesurethatDefrostPulseOverrideissettoYESsoDefrostRelay#1does
notpulseduringadefrostcycle(goto Settings →Equipment→Def.PulseOverr. andmakesureitissettoYES).
Iftheheatersareverifiedtobeworkingproperly,proceedtoverifydefrostcycleduration:onthecontrollerdisplay,goto
Status →Defrost→LastDefr.Time .Also,forceadefrostandwaitforittofinishtotakenoteoftheduration.CenterMount
Evaporatorstypicallyneedbetween20to30minutesdefrostdurationtocleartheice.Ifthedefrostcycleistooshort,the
DefrostTerminationTemperature(Def.Term.Temp )andRuntimeUntilDefrost(Def.Cmp.RunTime )canbeadjustedas
neededinSettings→Equipment .Iftheunitalreadyhassomeicebuiltupinthecoil,itmaytakeseveraldefrostcyclestoclear
theiceaftertheparametersmentionedaboveareadjusted.
Compressorcouldbeshuttingdown
intermittently.
Verifythatthecorrectrefrigerantisselected.
Doorisopen.
SuctionTempsensordisconnected(controllerwill
alarm;redLEDoncontrollerwillbeblinking),or
sensorcouldbemalfunctioning/readingerratic
value.
SuctionPressuretransducerdisconnected
(controllerwillalarm;redLEDoncontrollerwillbe
blinking),ortransducercouldbemalfunctioning.
9
10
Suctionlineatcompressorisicingup
excessively.
Systemcouldbeundercharged/leakpresentinthe
system.
12
Evaporatorcoilisicingup(CenterMount
FREEZER,electricdefrost).
UnitiscoolingbutSpaceTempnever
reachessetpoint.
Verifythatheatersareworkingwhencontroller
goesintodefrost.
Verifydurationofdefrostcycle/runtimebetween
defrosts.
Doorisbeingleftopen.
11
Evaporatorcoilisicingup(LowProfile
FREEZER,electricdefrost)
VerifyEXVisfunctioningproperly,closing
completelyforpumpdown.
VerifyEvapTemp1andEvapTemp2sensor
locations.
VerifyDefrostPulseOverrideissettoYES.
Doorisbeingleftopen.
Verifythatheatersareworkingwhencontroller
goesintodefrost.
Verifydurationofdefrostcycle/runtimebetween
defrosts.
Problem PossibleCause
Page2of4