PrecisionTemp TWINTEMP JR. Operating and installation instructions

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TWINTEMPJR.HYDRONIC
SYSTEM
2/2013
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TwinTempDescriptionofOperationandSequenceofOperation
TechnicalDescriptionofOperation‐TheTwinTempsystemsprovidequietspaceheatingutilizingliquidtoair
blowersorradiantdevices,whileproducingacontinuoussupplyofhotwater.ItsVariflamegasmodulationenablesitto
useaverysmalltankandstillmaintainefficiencywithoutrapidburnercycling.Thisgreatlyreducesstartuptimeand
standbyheatloss.UnlikeitsdieselcounterpartstheTwinTemphasaninstantonburnerandmodulatesthegasflowona
4‐1ratio.Acopperheatexchangerinsidethetankofheatedantifreezeinusedtoindirectlyheatthepotablewater.This
methodisnotonlyefficient,butwillextendthelifeofthecriticalheatexchangeelements,tankandcirculatingpumps.
SequenceofOperation
ThepowerandpropaneareturnedontotheTwinTemp.IftheTankthermostatsenseslowtanktemperature
(below190°F),itwillsend12vdcpowertothegreencontrolboardandPump1(rear)pump.Note‐theJuniorhas
onezonepumpandtheTwinTemp‐2has2zonepumps.
Anti‐freezestartstocirculatefromthebottomofthetank,throughPump1,totheburnerheatexchanger,outto
Zone1blowersandbacktotank.
Simultaneously,thecontrolboardpowersthepowerventrelaywhichactivatesthepowerventandfluingis
proofedbythepressureswitchviathe¼”hose.Thepressureswitchsends12VDCtotheignitionboard(ifflueis
blocked,burnerwillnotlight).
Thesolenoidgasvalveisenergizedandasparkiseffectedtotheigniterprobeoverburnerviatheyellowignition
wire.Theflameisproofedviathesameigniterelementandyellowwire.
Gasflowisadjustedbythegasmodulatingvalvebasedonantifreezetemperature.Temperaturereadingsare
takentwicepersecondbytheT‐MidThermistor.Assettemperature(about190°F)isapproached,thegasflowis
reducedasmuchas70%byreducingthevoltagetothegasmodulatingvalveuntilsettemperatureisachievedand
theburnergoesoff.
Whenahotwatertapisopened,coldwaterentersthecoppertankheatexchangerimbeddedinthetankandthe
heattransfertakesplace.Thehotwaterexitsthetankcoilthroughatemperingvalvethatcanbesettoany
temperaturebetween100°‐145°.Asthetankcools,theburnercyclestartsagainwhenthetankthermostatsenses
thetankisgettingcold.
Ifthezone1roomthermostatsenseslowroomtemperature,itsendspowertothezone’srelaythatthenpowers
pump1,controlboardandthezoneblowersthroughthe160degreetankswitch.
Whenthezone2(TwinTemp‐2only)thermostatcallsforheatthezone2relaysendspowertothepump2andthe
blowersinzone2areactivated.Theburnerwillbeactivatedbythetankthermostatasaboveiftheantifreeze
temperaturefallsbelowsettemperature.
TheblowerthermostatswitchwillturnofftheZone1blowersiftanktemperaturedropsbelow160°F.orwill
keepblowersoffuntiltanktemperaturereaches160‐170degreesoncoldstart.
NOTE:Theboldorangetermsareidentifiedandpicturedinthefollowingpages.
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TwinTemp Preventive Maintenance Schedule
It is recommended that the TwinTemp be inspected by a qualified service
technician at least once a year.
1.Clean interior of TwinTemp cabinet including
combustion air intake grill. ***
2.Inspect all wiring connectors for corrosion and
looseness. Tighten and or repair if needed. ***
3.Performance test heating and hot water functions.
***
4.Check interior and exterior plumbing connections
for fluid leak. **
5.Check propane connections for leaks. **
6.Check boiler antifreeze level in overflow tank.****
7.Drain and refill boiler antifreeze. ***
(Use only Rhogard boiler antifreeze or equivalent with
Aluminum tank)
8. Rotate Mixing valve knob clockwise and counter
clockwise. **
9.All faucet aerators and showerhead screens in the
coach should be cleaned regularly.***
** Bi-Annually
*** Perform every 12 months
**** Bi-Monthly
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TwinTemp2/Jr.Diagnostics&TroubleShooting
A. UseRhogardBoilerantifreezewithProtek922additiveor
equivalentwithAluminumtank.Camcoisacceptablewith
stainlesssteeltank.
1. Mixantifreeze50/50withdistilledwater
2. Totalamountofantifreezeheldinhydronicsystemofa
Newmarcoachisapproximately5.5gal.
3. Alwayscheckfluidlevelandcondition.
4. Commoncauseofcontamination;
a. Repeatedintroductionofairinclosedsystemcausing
fluidcontamination.
b. Plumbingleaks,radiatorcap,etc.
c. Donotmixwinterizingafrz.orethyleneglycolafrz.
withpropyleneglycolboilerantifreeze.
d. Effectsofcontamination,sludge,metalcorrosion.
B. Startingdiagnosticscheckbasics;power,faultcodes,etc.
thenusethesequenceofoperationtoaiddiagnostics.
1. Twocallsforignition,Antifreezetemperature(tank
thermostatswitch)andinteriorthermostat.
C. Causesandsymptomsofrestrictedflow.
1. Sludge/restrictioninplumbingloop.
2. Kinkedplumbinglinesorconnections.
3. Soundsassociatedwithrestrictedflowarerattling
knockingnoiseduringpropaneignitionwithignitiononly
lasting10‐20seconds.

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4. Monitortmidtestpoint(yellow)duringignitionfora
rapidDCvoltagedropi.e.2.0vDCdropto.5vDCin10‐30
secondsindicatingrestrictedflow.
D. Plumbingrestrictions:Supplylinehotreturnlinewarm/cool
whileinwintermode.
1. Summer/Wintervalvemayallowfluidtobleedthroughif
restrictionisinthehydronicloopcausingtheTTto
appeartooperatenormally.
E. Newmarusesrelaysmakingasinglezonesystemintotwo
zonesystembycontrollingtheheatregisterfans.
1. TheTwinTempthermostatandblowersignalgoestothe
bankofrelaysandthendistributedtothecoachwiring.
F. Summer/wintervalvepositions.
G. Electricelementoperation.
1. Usedasstandaloneforlimitedhotwaterorusedin
conjunctionwithpropanetoreducepropane
consumptionineithersummerorwinteroperation.
2. Overheatreset&electricelementECO
3. Lowfluidlevelintankwillmakeboilingnoisewhen
electricelementisinuse.
H. Hotwaterproduction
1. Mixingvalve.
2. Summerhotwaterproduction,2.25gallonsofantifreeze
heated.
3. Winterhotwaterproductiondelayeduntil5.5gallonsof
antifreezeareheatedcausingshortdelayinhotwater
production.
1. Currentvendorpartissues.NONE

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TwinTempHydronicHeating/WaterHeatingOperatingInstructions
Formaximumheatandhotwateroutput,itisrecommendedtousetheLPGmodeofoperationinadditiontothe
120voltelectricelement.Electricelementoperationshouldbeusedforminimalhotwaterdemandsuchas
washinghandsordishes.Itisnotnecessarytohavethewatersystemfilledtousethespaceheatingsystem,but
theheatingsystemmustbefilledwithanti‐freeze.
ToStartUpSystem:
Turnonthepropanesupply.
Turnon12voltpowerswitchontherightsideoftheTwinTempcabinet.
Turnon12voltpowerswitchoncoach,ifapplicable.
Burnerwillstart‐upandsystemwillbeuptooperatingtemperatureinapproximately10‐15minutes
dependingonpositionofSummer/wintervalve.
SummerOperation
PositionSummer/WintervalveinSummerposition.
WhenthespaceheatingfunctionoftheTwinTempisnotneeded,theheatedanti‐freezeshouldnotbecirculated
totheblowers.Topreventthiscirculation,theSummer/Winterby‐passvalveshouldbeturned¼turn.When
heatingisagainneeded,thisvalvehandleshouldbeturned¼quarterturnfromtheSummerpositiontothe
Winterposition.Thisadjustmentshouldonlybeneededtwiceayearforsummer/winteroperation.
  
SummerWinter
ForSpaceHeating:
PositionSummer/WintervalveinWinterposition.Turnonmaincoachthermostatandsettodesired
temperature.Whenthesystemreachessettemperaturetheblowerswillturnonandheatisdelivered.When
roomreachessettemperature,thepumpandblowersforthatzonewillgooff.Iftanktemperatureisbelowset
temperaturetheburnerwillstayonuntiltankreachessettemperature.NOTE:theheatregisterblowerswillnot
activateifthetanktemperatureisbelow160˚F.Thisassuresthatthehotwaterfunctiontakespriorityunder
heavyusageconditions.Blowerswillresumeoperationwhentankreturnstooperatingtemperature.

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ForHotWater
TwinTempunitandwatersystempumpmustbeturnedonorconnecttocitywatersystem.Turnonhotwater
tap.Note:Duringheavyheatandhotwaterdemand,thehotwatersystemtakespriorityandtheheatregister
blowersmayshutoffbrieflytomaintainhotwatersupply.Hotwatertemperatureisfactorysetatapproximately
120degrees.Tochangetemperature,consulttheoperatingmanual.
Oncethetankreachessettemperature(5‐15minutesaftersystemisturnedon),continuoushotwateris
deliveredwhenanytapisopened.Deliverytemperatureisdeterminedbythesettingoftemperingvalve
Warning:thisvalveisfactorysetatabout120˚F.adjustingtemperatureanyhighercouldresultinsevereinjury
duetoscalding.
Tankthermostatturnspump1andburneronautomaticallywhentanktemperaturestartstodrop.Anti‐freeze
circulatesfromburnerandbacktotankasitheats.Burnerremainsinhighfireandgasmodulatesburnertolow
burnuntilsettemperatureisattained.Whensettemperatureisreached,burnerandpumpshutdownand
systemreturnstostand‐bymode.
WinterModeHotWaterProduction
Duringwinteroperationifthesystemhasbeendormantformorethan20minutesturnoninteriorthermostatto
callforheat.Whentheheatregisterblowerscomeonturnoffthermostatandturnonhotwatertap.Preheating
thesystemisrequiredinwintermodeforhotwaterproductiondueto3gallonsofcoldfluidinthehydronicloop
suddenlybeingreturnedtotheTwinTemptankloweringthefluid(boilerantifreeze)temperaturerequiredforhot
waterproduction.Oncefluidtemperaturereachessettemperaturethesystemwillmakecontinuoushotwater.
ToUseWith110VoltHeatingElement
Turnon110voltelementswitchlocatedinsidecoach.Lettheunitheatupforaminimumof30‐60minutes.
Note:Inthe110voltmodeofoperationtheelectricelementsuppliestheheatuntildemandexceedsitscapacity
atwhichtimegasburnerautomaticallyignites.
TheTwinTempJr.isequippedwithone110VACelectricheatingelement.Theelementprovideslimitedamounts
ofhotwaterorspaceheating,suchaswashinghandsordishes.Theelectricelementcanbeusedwithorwithout
thepropaneburner,butforcontinuoushotwaterorspaceheat,thepropaneburnermustbeused.Tooperate,
turnthe110voltswitchoninthecoach.Forsmallamountsofhotwateronly,thereisnoneedtoturnthe12volt
powerontotheTwinTemp.However,ifspaceheatisrequiredinverycoldweather,the12voltswitchshouldbe
turnedon.Ifthereisahigherdemandforheatthanthe110voltelement(s)canprovide,thepropaneburnerwill
activateautomatically.Forbestoperation,turnthe110voltelementonabout30minutesbeforeturning12volt
switchon.Thisallowsthetanktocomeuptotemperatureutilizingtheelectricelementbeforetheburnercan
activate.Thiswillhelpconservepropane.