Thermann 26NG50C User manual

GAS CONTINUOUS FLOW
WATER HEATERS
(Residential Outdoor Unit)
TO BE USED BY A LICENSED
PLUMBER ONLY
SERVICE MANUAL
Model:26NG50C/26LP50C
26NG60C/26LP60C

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Table of Contents
1. General Outline of Appliance
1 - 1 Specications .............................................................................................................................. 3
1 - 2 Performance................................................................................................................................ 4
1 - 3 GeneralConstruction(PartsNames) .......................................................................................... 5
1 - 4 MainComponentStructures ....................................................................................................... 6
1 - 5 MainSafetyDevices ................................................................................................................... 8
2. Installation and Related Work
2 - 1 InstallationInstructions................................................................................................................ 9
2 - 2 Dimensions ................................................................................................................................. 13
2 - 3 GasPiping................................................................................................................................... 14
2 - 4 WaterPiping................................................................................................................................ 14
2 - 5 CondensateDrainPiping ............................................................................................................ 15
2 - 6 ElectricalConnection .................................................................................................................. 17
2 - 7 WiringRemoteController............................................................................................................ 18
2 - 8 TestingOperation ........................................................................................................................ 20
2 - 9 CascadeInstallation.................................................................................................................... 21
3. Service and Maintenance
3 - 1 OperationPrinciples.................................................................................................................... 22
3 - 2 SchematicDiagram..................................................................................................................... 24
3 - 3 FlowCharts ................................................................................................................................. 25
3 - 4 FaultFindingsandErrorCode .................................................................................................... 26
3 - 5 ReplacementofPCB................................................................................................................... 29
3 - 6 ReplacementofNeutralizer......................................................................................................... 30
3 - 7 WiringDiagram ........................................................................................................................... 31
3 - 8 CascadeFlowCharts.................................................................................................................. 32
3 - 9 ManifoldGasSettingProcedure ................................................................................................. 33
3 - 10CombustionSpecication,VariousCombinationSetting ............................................................ 34
3 - 11 Disassembling/AssemblingParts................................................................................................ 38
3 - 12ExplodedView ............................................................................................................................ 46
3- 13PartsList ..................................................................................................................................... 47

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1-1 Specications
MODEL 26
Nominalhourlygasconsumptionby
proportionalelectronicgascontrol MJ/h 173
Minimumgassupplypressure(NaturalGas) kPa 1.13
Maximumgassupplypressure(NaturalGas) kPa 5.0
Minimumgassupplypressure(Propane) kPa 2.75
Maximumgassupplypressure(Propane) kPa 7.0
TestpointpressureHigh(NaturalGas) kPa 0.84
TestpointpressureLow(NaturalGas) kPa 0.16
TestpointpressureHigh(Propane) kPa 1.27
TestpointpressureLow(Propane) kPa 0.21
Waterheatingcapacityraised40°C L/min 16.25
Minimumworkingpressure kPa 115
Maximumworkingpressure kPa 1200
Gasinjectorsdiameter(NaturalGas) mm 1.00/1.50
Gasinjectorsdiameter(Propane) mm 0.7/1.0
Inputvoltagesinglephase50Hz V240
Maximumoutputcurrent A0.66
Inletgasconnectionmalethread R3/4”(20mm)
Coldwaterconnectionmalethread R3/4”(20mm)
Hotwaterconnectionmalethread R3/4”(20mm)
Reliefvalvepressuresetting kPa 1400
Weightdry kg 20.5
Dimensions(DxWxH) mm 205x366x573
IAPMOApprovalcerticateno.GMK10408.WatermarkCerticateofcomplianceWM-000506
1. General Outline of Appliance

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1-2 Performance
Performance-Capacitycharacteristiccurves.
Inlet water temperature
5C
15 C
25 C
Water flow rate [L/min]
37
0
5
2.2(Minimum)
22.0(Maximum)
10
15
20
25
7550 60
Outlet water temperature [
C]

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1-3 GeneralConstruction(PartsNames)
No. PARTS NAME
1PCB(Natural Gas)
PCB(Propane)
2ManifoldAssy(NaturalGas)
ManifoldAssy(Propane)
3GasControlValve
4Electrode
5FlameRod
6HeatExchangerAssy
aPrimaryHeatExchangerAssy
b SecondaryHeatExchangerAssy
7OverHeatThermostat
No. PARTS NAME
8 Fan Motor
9TemperatureSensor
10 Anti-Frost Heaters
11 Ignitor
12 PressureReliefValve
13 WaterFlowControlValve(withSensor)
14 Water Filter
15 AmbientTemperatureSensor
16 NeutralizerAssy
c Neutralizer
dAnti-FrostHeaterforNeutralizer
a
7
10
5
4
10
b
6
14d 10
11
1
15
2
10 12 13
c
8
9
9 3

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1-4 MainComponentStructures
1. GasControlValve
•Feedsthenecessaryamountofgastoheatwatertoasettemperature,basedonthe
amountofwaterowinginthroughtheinletmeasuredbytheWaterFlowSensorand
thewatertemperaturecalculation.
UP34-47R
LP/NG
4D00001
11DC0697
0
1
2
OUT2OUT1
Main Gas Valve
Gas Valve 1
Filter
Gas Control Valve
Gas Valve 1
(No.1)
Main Gas Valve
(No.0)
Gas Valve 2
(No.2)
IN
2. WaterFlowControlValvewithSensor
*Measuresthewaterowasitsrotor(bladedwheel)spinswiththepassingwater.
Therotationoftherotorisdetectedbythesensorrotor(bladeequippedwitha
magnet)ofthewheelandtheHallelementwhichcalculatesthewaterquantity.
*Whenwaterowsmorethanwaterheatercapacity,hotwatertemperaturebecomes
lowerthanthesetting.TheWaterFlowControlValveautomaticallyreducesthe
waterowtopreventsuchtemperaturedrops.
Inlet
Main Body
Water Flow Sensor
Hall Element IC
Sealant
Valve Body
Water Flow
Control Valve
Rotor

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Gas
Gas Valve 2
Gas Valve 1
Electrode
2burners 5burners 10burners
Flame Sensor
Gas Control
Valve
Main Gas Valve
Gas Valve 3
Fan Motor
3. CombustionControlofRichandLeanBurners
1) Ignitionstart
AftertheMainGasValve,GasValve1,GasValve2openrespectivelyasrequired,
theGasControlValve,beingheldattheslowignitionposition(withgassupplyata
constantrate),operatestoigniteBurners.
2) Duringcombustion
Dependingontherequiredheatingcapacity,eachGasValveopensorcloses.
The combinations are below,
Gas valve 1&2&3 open
1&2
2
1
Higher
Lower

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1-5 Main Safety Devices
1. WaterFlowSensor(Boil-dryprotection)
WhentheWaterFlowSensordetectstheowrateissetforstartingignition(ignition
waterow)orhigher,thewaterheaterstartsoperation.
 Ignitionwaterow:2.7L/min.
 Extinctionwaterow:2.2L/min.
2. FlameSensor(Flamefailuredetection)
Electricsignalsaretransmittedtotheamedetectioncircuittoconrmthenormal
combustionwhentheFlameSensordetectstherecticationofnormalcombustion
ame.Therefore,ifthecombustionoftheBurnersisnotnormal,thesignalsarenot
sentviatheFlameSensor.Thegascontrolassembliesareclosedwithoutthesignals
andtheerrorcode"111"or"121"isdisplayedontheremotecontrollers.
3. ThermalFuse(Over-temperatureprotectionsystem)
TheThermalFuseisplacedaroundthePrimaryHeatExchangerAssembly.Ifthe
ambienttemperatureinsidethewaterheaterbecomesextremelyhigh,thefusewill
meltdowntobreakthepowercircuit.Insuchacase,asnopowerissuppliedtothe
gascontrolassemblies,thegassupplyisstoppedandthecombustionisstopped.
(Thesystemisactivatedtoblowthefuseat169°C.)
4. OverHeatThermostat(residual)
EvenifthePrimaryHeatExchangerAssemblyisoverheatedbyno-watercombustion,
everygaspathisclosedtoavoidrisks.Atthistime,theerrorcode"141"isdisplayed
ontheremotecontrollers.
(Theswitchisprovidedwithaauto-restorationfunctionandturnsOFFat100°C.)
5. FanRevolutionDetectionDevice(HallIC)
Thedevicedetectsthefanrevolutionspeedtocontroltheairsupplynecessaryfor
normalcombustion.Ifthefanrevolutionisoutofthepresetstandardrange,thegas
controlassembliesareclosedtostopthecombustionbeforecombustionfailure
occurs.Inthiscase,theerrorcode"611"isdisplayedontheremotecontrollers.
6. FreezeProtectionSystem(Anti-FrostHeaters)
Topreventfreezinginthehotwatersupplycircuit,Anti-FrostHeatersareprovidedat
majorpointsofwaterowpathsintheunit.TheheatersareactivatedbytheAmbient
TemperatureSensorintheunit.
(ThesystemturnsONat3°CandOFFat13°C.)

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2. Installation and Related Work
2-1 Installation Instructions
•Thecasesshownbelowareclassiedbythedegreeofriskanddamage.
Besuretofollowtheinstructionsforyoursafety.
Eachmarkindicates:
TheWaterHeatermustbeinstalledinaccordancewiththefollowing:
1. Theseinstructions.
2.NationalConstructionCodeandLocalauthorityregulations.
3. AS/NZS3500.4PlumbingandDrainage-HeatedWaterServices.
4. TheAustralianstandardforgasinstallationsAS/NZS5601.
5. Anyotherstatutoryregulationthatmayapply.
6. AnoticeofintentiontoinstallshallbelodgedwiththerelevantlocalGasAuthorityprior
to installation.
INSTALLAION MUST BE CARRIED OUT ONLY BY AN AUTHORISED AND
APPROPRIATE LICENSED PERSON
Installationrequirements
“Danger”indicatesthatseriousinjuriesorevendeathmayresultfrom
theimproperinstallationduetonegligenceoffollowingtheinstructions.
“Warning”indicatesthepossibilitythatseriousinjuriesorevendeath
mayresultfromtheimproperinstallationduetonegligenceoffollowing
theinstructions.
“Caution”indicatesthepossibilitythatsomeinjuriesormaterialdamage
mayresultfromtheimproperinstallationduetonegligenceoffollowing
theinstructions.
Generalprohibited
Neverfailtodo.
Ground
Neverinstalltheunitindoorsasitisexclusivelyforoutdooruse.
Donotinstallitinthebathroom.Electricshockorleakagemayresult.

-10- - 11 -
•Makesuretheunittobeinstalledsuitstheintendeduseandapplication.
•Donotuseanygasotherthanspeciedonthesticker.
•Donotoperatewithanypowersource(voltage/frequency)otherthanspeciedonthe
sticker.
Vericationoftheunit.
Before installation.
Locationoftheunit.
Decidewheretoinstalltheunitbyconsideringcustomer’srequestandclearances.
Ventilation
•Installtheunitwherethereisenoughspaceforventilation.
•Donotinstalltheunitwhereammablessuchasgasoline,benzene,andadhesiveare
handled.
•Thisunitdoesnotallowtheuseofextendedexhaustpipes.
•Installtheunitasfaraspossible,awayfromanythinginfrontoraboveevenifitisnon-
combustibleinordertopreventexhaustgasrecirculation,andstainingofsurfaces.
•Takepreventivemeasuresagainstsnowdriftsforairinletandexhaustoutlettostay
unaffectedincasethereisapossibilitythattheymaybeblockedbysnowfall.

-10- - 11 -
•Reinforcethewallifnecessaryasthisunitweighsabout20.5kg.
1. Fix1screw(forwallhanging)intothewallleavingabout4mmlengthtohookon.
2.Hookthecenterholeofthewallhangingbracketontothescrewandsecurelyxthe
unitwith4screws.
Installation.
Screw
(for wall hanging)
Wall hanging bracket
Screw
(for wall hanging) Wall hanging bracket
4mm
599mm
Screw
(for wall hanging)
Screw
(for wall hanging)
Screw
(for wall hanging)

-12- - 13 -
•Checkifadjacentwallorceilingisreresistantandallowssafedistanceforre
prevention.
•Thiswaterheaterissuitableforresidentialwater(potable)heatingonly.Donotusethis
waterheaterforspaceheating,combinationspaceheating/domesticwaterheating,or
commercialwaterheatingapplications.
•TheWaterHeaterisnotsuitableforuseinpoolorspaapplications.
•Maintainproperspacearoundtheunitforproperservicingandoperation.Minimum
clearancesfromcombustiblematerialsarelistedbelow.
Topofheater 30cm
Frontofheater 60cm
Sidesofheater 15cm
Backofheater 0cm
Floor 30cm
•Secureenoughspacesothattheinspectionandrepairscanbedoneeasily.
•Securespacenotonlyinfrontbutalsoundertheunit.
•Donotinstalltheunitoverothercombustionappliances.
OilresidueanddustintheaircanadheretotheBurnerandthePrimaryand
SecondaryHeatExchangerresultingindeformation,lossofefciency,ordamageto
electroniccomponents.
•Donotinstalltheexhaustoutletneartheoutletsoftheotherappliances.
Installtheairinletsawayfromthewindpathasthewindmaycauseimperfect
combustion.
•Donotinstalltheunitwherecommercialchemicalsareused.
Thosechemicalsareammonia,sulfur,chloride,ethylenecompoundandacidswhich
areusedatbeautyshop,laundry,factoryandsoforth.
•Donotinstalltheunitoverfoodordishes.
•Pipepressurerelieftoadrainoroutsideenvironment,orwithin100mmoftheoor.
Pipepressurereliefdischargetoadrainoroutsideenvironment.
•Theapplianceshouldbelocatedinanareawhereleakagefromtheunitorconnections
willnotresultindamagetotheareaadjacenttotheapplianceortoloweroorsofthe
structure.Whensuchlocationscannotbeavoided,itisrecommendedthatasuitable
drainpan,adequatelydrained,beinstalledundertheappliance.Thepanmustnot
restrictcombustionairow.

-12- - 13 -
2-2 Dimensions
68mm68mm
68mm68mm
637mm
573mm 25mm
366mm
599mm 12mm
15mm
205mm21mm
143mm
103mm
83mm
145mm
72mm
350mm
260mm
208mm
174mm
143mm
46mm
POWER CABLE ENTRY
DRAIN OUTLET
COLD WATER INLET
R3/4 /20
PRESSURE RELIEF VALVE
HOT WATER OUTLET
R3/4 /20
GAS SUPPLY INLET
R3/4 /20
WATER INLET FILTER

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•InstallthemanualgasvalveinthegasinletconnectionoftheWaterHeater.
•Aunionshouldbeusedtoconnecttheunitandthegaspipe.
•Checkthegastypeandthegasinletpressurebeforeconnecting.
•Removethescrewfromthetestplugbeforecheckingthegasinletpressure.
Connectthemanometertotheplugwiththesilicontubeandmeasurethegasinlet
pressureandconrmfromtheratinglabelontheappliance.
•Putthescrewbackinthetestplugandfastentightly.
•Makesuretoconductgasleakagetestbeforeoperatingthe
Water Heater.
2-3 Gas Piping
2-4 WaterPiping
•InstallamanualwatervalveinthewaterinletconnectionoftheWaterHeater.
•Aunionshouldbeusedonboththehotandcoldwatersupplylinesforconnection.
•Purgethewaterlinestoremovealldebrisandair.
•Makesureboththehotandcoldwatersupplylinesareconnectedcorrectly.
•Alterisplacedatthewatersupplyinlettoremovedebris.
Cleanthelterregularly.
Donotoperatetheunitwithoutthelterinplace.
Inareasofheavydebris,suchaswithsomewells,installawholehousewaterlterinline
beforetheunit.

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2-5 Condensate Drain Piping
Thisunitgeneratescondensatecontinuouslyatarateofupto5litresperhourasa
by-productofthehighlyefcientgasburnersystem.
Thiscondensatemustbedrainedviaapipetoasuitablepointofdischarge.Asthe
condensateisaby-productofgascombustion,itismildlyacidic.
Forthisreason,coppertubeandttingsMUSTNOTbeused,astheywillcorrode.
Theunithasanin-builtcondensateneutralizertomakethecondensatesafefordischarge.
ItisrecommendedtouseDN15highpressurePVCpipeandttingsforthecondensate
drain line.
IMPORTANT CONSIDERATIONS FOR THE CONDENSATE DRAIN PIPE
ThecontentofAS/NZS3500‘Temperature/PressureReliefandExpansionControlValve
DrainLines’hasbeenusedasaguideinpreparingtheseconsiderations.
Condensatedrainoutletconnection,R1/2"(15mm)BSPmalenylon.
Note:thewhiteplasticshippingcapMUSTBEremovedfromthecondensatedrainoutlet
priortowaterheateroperation.Inthecasethatwhite-ishstonepieces(calciumcarbonate)
comesoutoftheneutralizerwhenthecapisremoved,theyshouldbediscarded.
Thecondensatedrainlinemusthaveacontinuousfall(ofatleast2°)fromthewater
heatertothedischargepoint.Lengthsandbendsmustbeinaccordancewith'Lengthand
changesofdirection'diagrambelow.
Drainage of condensate water
Lengths and changes of direction
Maxreliefdrainlength(m) 9876
Maxnumbersofchangesofdirection(greaterthan45°) 3456
Drain outlet
2° fall
Fix with pipe clip
PVC piping

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1. ThedrainlineMUSTNOTdischargeontoelectricalconnections,earthstakes,copper
pipes,concretepathsorintoapond.
2.Thepointofdischargefromeachdrainlineshallbelocatedsothatthereleaseof
condensatedoesnotcauseanuisance,isreadilydiscernableandincursnoriskof
damagetothebuilding.
Condensatedrainlinesfrommultiplewaterheatersmaybejoinedtogetherprovidedthey
conformwiththe'Installationrequirements'onpage9.
Whereindividualwaterheatersareinstalledinamulti-storybuilding,thecondensatedrain
linemaydischargeintoacommonstack,subjecttothefollowing:
(a) Thedischargefromthecommonstackistoatundish,havingadischargelinethatis
notlessthanthesizeofthecommonstack,directlyconnectedtoaxturetrap,and
installedinconnectionwithanyadjacentsoilorwastestack.
(b) Thedischargepointofthecommonstackissuchthatanydischargeisreadilyvisible
andnotcauseanynuisance.
(c)Thecommonstackisventedbyextendingthepipeupwardsabovetherooflevel.
ThedrainlinefromanytundishshallnotbelessthanDN20orlessthanonesizelarger
thanthatofthelargestdrainlinedischargingintothetundish.Tundishdrainlinesshall
complywiththe’Installationrequirements’onpage9.
Inareaswherewaterpipesarepronetofreezing,thedrainpipefromanyvalveshallbe
insulatedandnotexceed300mminlength.Itshalldischargeintoatundishthroughan
airgapofnotlessthan75mmandnotmorethan150mmmeasuredfromtheoutletofthe
drainpipetotherimofthetundish.
Installation
Interconnection of condensate drain lines
Commonstackdischarge
Tundish drain lines
Areas subject to freezing
Inviewof(1)and(2),suitablepointsofdischargearedeemedtobedrainsorsewers.
3. Thereshallbenotap,valve,orotherrestrictionsinanyline.
4. Thedrainlineshallfallcontinuouslytotheapprovedpointofdischarge.
5. Wheredischargingoveratundishorgullytrap,drainlinesshallhaveanairgapofa
sizeatleasttwicethediameterofthedrainline.
PLEASE NOTE
Thewarrantywillnotcoveranyfailuresoroperatingdifcultiesduetothefollowing:
•improperinstallationandmaintenance(includingbutnotlimitedto):
•condensatedamageoranyotherconsequentiallosseitherdirectlyorindirectly
•removaloftheneutralizer
•notreplacingtheneutralizerattheendofit’slife

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2-6 Electrical Connection
•TheWaterHeaterrequires240VACat50Hz.
Disconnectthepowersupplyiftheunitisnotinuseforalongtime.
•Removeresidualwaterintheunitwhenthepowersupplyisoffbecausethefreeze
preventionintheunitwillnotactivate,resultinginpossiblefreezingdamage.
•Labelallwirespriortodisconnectionwhenservicingcontrols.Wiringerrorscancause
improperanddangerousoperation.
Verifyproperoperationafterservicing.
Fieldwiringtobeperformedattimeofapplianceinstallation.
•Completelyturnoffthepowerbeforestartingthework.
Donotturnthepoweronuntiltheelectricwiringisnishedandallworkiscompleted.
Otherwiseelectricshockorpersonalinjurymayresult.

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2-7 WiringRemoteController
1. Numberofcontrollers
One,twoorthreeremotecontrollerscanbeinstalledasoptionalextras.
2. RemoteControllerlocations
Theremotecontrollersallowthewatertemperaturetobesetfromthevarious
locationswheretheyareinstalledatkitchen,laundry,bathroomandensuite.
3. Connectionofcabletothethermannunit
(1)Removethefrontcoverfromtheunit.
(2)InstallthecabletotheThermannmainunitusingconduitorbyconcealingthe
cablesinthewallcavity.
(3)Installthecableintothecabinetthroughtheconduitinaccordancewiththetablein
nextpage.
(4)Basedon“Howtoxthecables”,attachthecabletotheplateadjacenttothe
terminalblock,usingthecableclampprovided.
(5)Attachthecablestotheterminalsfortheremotecontrollers.
(6)Replacethefrontcoverofthewaterheater.

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L SM SMS
180mm
270mm
KNOT
KNOT
180mm
KNOT
180mm
KNOT
KNOT
270mm
KNOT
270mm
KNOT
KNOT
How to fix the cables (Remote controller cable(s) and cascade cable)
Number of cable
How to tie the
cable(s) at the
power cable
entry
Required cable
clamp
How to fix the
cable(s)
The length
between the knot
and the cable
terminal
How to connect
the cable(s) to
the terminal
1 2 3 4*
Make a knot Tie two cables
Tie two cables and
make a knot on the
rest cable
Tie the cables
two by two
Clamp (small) Clamp (medium) 1 cable:clamp (small)
2 cables:clamp (medium)
1 cable:clamp (small)
3 cables:clamp (large)
180mm 180mm 1 cable:270mm
2 cables:180mm
2 cables:270mm
2 cables:180mm
Attach the cable to
underside of terminal
Attach the cables to
underside of terminal
Attach the cable(180mm)
to underside of terminal
Attach the cables(270mm)
to upperside of terminal
Attach the cables(180mm)
to underside of terminal
Attach the cables(270mm)
to upperside of terminal
* Up to three remote controller can be installed. In this case, three remote controller cables and one cascade cable shall be connected.

-20- -21-
2-8 TestingOperation
•Followthestepsbelow,toensuretheWaterHeaterhasbeenproperlyinstalled.
1. Fullyopenthewatersupplymainvalve.
2.Flushoutthewatersupplypipingtocleanoutanyinstallationdebris,cleanoutlter.
3. Turnonpowertounitandopengassupplyvalve.
4. Operatetheremotecontrollersaccordingto“INITIAL SETTING REMOTE
CONTROLLERS”intheinstallationinstructions.
1. Operatetheunitaccordingto"OperationofRemoteController”intheoperating
instructions.
2.Makesuretheunitoperatesnormally.
•DoestheBurnerigniteandshutoffproperly?CheckthecombustionlamponthePCB.
TheBurnermaynotigniteatrstuntiltheairinthegassupplypipeisdrivenout.
Repeattheprocedureuntilitignites.
•Istemperaturesettingworkable?
Checkifthetemperaturecanbeadjustedasdesired.
•Iftheresidenceisnotreadyforhabitationortheunitwillnotbeusedforanextended
time,theresidualwaterintheunitandthepipemayfreezeanddamagetheunit,orthe
residualwaterinthePrimaryandSecondaryHeatExchangermaydeteriorate.
Besuretoremovethewaterintheunitandthepipe.
1. Closethegassupplymainvalve.
2.Closethewatersupplymainvalve
3. Takeoffthewaterlterandpressurereliefvalve(drainstopper),andremovethewater.
Takethisprocedurewhentheunitcoolsdownafterthetestingoperation.
4. Disconnectthepower,orturnoffthepowersupply.
5. Openthetapandshowertap(ifany)andremovethewater.
6. Leavetheunitinthisconditionuntilreadytouse.
Filloutthewarrantyformwiththecustomer.
Explainthe“RemoteController“sectionoftheoperatinginstructionstothecustomer.
Preparation for testing operation.
Testing operation.
Procedure after testing operation.
Explanationtocustomers.