Baxi 47 075 35 Release note

UKCompNo5122323Iss138/12
Installation&ServicingInstructions
DuotecCombiHEARange
GasFiredWallMountedCondensingCombinationBoiler
TheseinstructionsincludetheBenchmarkCommissioningChecklistandshouldbeleftwiththeuserforsafekeeping.
©BaxiHeatingUKLtd2012
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NaturalGas
BaxiDuotecCombi24HEA
G.C.No4707535
BaxiDuotecCombi28HEA
G.C.No4707536
BaxiDuotecCombi33HEA
G.C.No4707537
BaxiDuotecCombi40HEA
G.C.No4707538
TheBenchmarkScheme
Benchmarkplacesresponsibilitiesonbothmanufacturersandinstallers.Thepurposeistoensurethatcustomersareprovidedwiththe
correctequipmentfortheirneeds,thatitisinstalled,commissionedandservicedinaccordancewiththemanufacturer'sinstructionsby
competentpersonsandthatitmeetstherequirementsoftheappropriateBuildingRegulations.TheBenchmarkChecklistcanbeusedto
demonstratecompliancewithBuildingRegulationsandshouldbeprovidedtothecustomerforfuturereference.
Installersarerequiredtocarryoutinstallation,commissioningandservicingworkinaccordancewiththeBenchmarkCodeofPractice
whichisavailablefromtheHeatingandHotwaterIndustryCouncilwhomanageandpromotetheScheme.Visitwww.centralheating.co.uk

formoreinformation.
©BaxiHeatingUKLtd2012Allrightsreserved.
Nopartofthispublicationmaybereproducedortransmittedinanyformorbyanymeans,orstoredinanyretrievalsystemofanynature
(includinginanydatabase),ineachcasewhetherelectronic,mechanical,recordingorotherwise,withoutthepriorwrittenpermissionofthe
copyrightowner,exceptforpermittedfairdealingunderCopyrights,DesignsandPatentsAct1988.
Applicationsforthecopyrightowner'spermissiontoreproduceormakeotheruseofanypartofthispublicationshouldbemade,giving
detailsoftheproposeduse,tothefollowingaddress:
TheCompanySecretary,BaxiHeatingUKLtd,
BrooksHouse,CoventryRoad,Warwick.CV344LL
Fullacknowledgementofauthorandsourcemustbegiven.
WARNING:Anypersonwhodoesanyunauthorisedactinrelationtoacopyrightworkmaybeliabletocriminalprosecutionandcivilclaims
fordamages.
BuildingRegulationsandtheBenchmarkCommissioningChecklist
BuildingRegulations(England&Wales)requirenotificationoftheinstallationofaheatingappliancetotherelevantLocalAuthorityBuilding
ControlDepartment.From1April2005thiscanbeachievedviaaCompetentPersonsSelfCertificationSchemeasanoptiontonotifying
theLocalAuthoritydirectly.SimilararrangementswillfollowforScotlandandwillapplyinNorthernIrelandfrom1January2006.
TheHealth&SafetyExecutiveoperatesthe'GasSafeRegister',aselfcertificationschemeforgasheatingappliances.
ThesearrangementsrepresentachangefromthesituationwherebycompliancewithBuildingRegulationswasacceptedasbeing
demonstratedbycompletionoftheBenchmarkLogbook(whichwasthenleftonsitewiththecustomer).
WiththeintroductionofSelfCertificationSchemes,theBenchmarkLogbookisbeingwithdrawn.However,asimilardocumentintheform
ofacommissioningchecklistandserviceintervalrecordisincorporatedatthebackoftheseinstructions.
ThiscompanyisamemberoftheBenchmarkinitiativeandfullysupportstheaimsoftheprogramme.Itsaimistoimprovethestandards
ofinstallationandcommissioningofcentralheatingsystemsintheUKandtoencouragetheregularservicingofallcentralheating
systemstoensuresafetyandefficiency.
BuildingRegulationsrequirethatinstallationsshouldcomplywithmanufacturer'sinstructions.Itisthereforeimportantthatthe
commissioningchecklistiscompletedbytheinstaller.TherelevantsectionofBuildingRegulationsonlyrelatestodwellings.Thereforethe
checklistonlyappliesiftheapplianceisbeinginstalledinadwellingorsomerelatedstructure.
TheflowchartBelowgivesguidanceforinstallersontheprocessnecessarytoensurecompliancewithBuildingRegulations.
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InstallerNotificationGuidelines

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IMPORTANTInstallation,Commissioning,Service&Repair
Thisappliancemustbeinstalledinaccordancewiththemanufacturer'sinstructionsandtheregulationsinforce.Readtheinstructionsfully
beforeinstallingorusingtheappliance.
InGB,thismustbecarriedoutbyacompetentpersonasstatedintheGasSafety(Installation&Use)Regulations.
Definitionofcompetence:ApersonwhoworksforaGasSaferegisteredcompanyandholdingcurrentcertificatesintherelevantACS
modules,isdeemedcompetent.InIE,thismustbecarriedoutbyacompetentpersonasstatedinI.S.813"DomesticGasInstallations".
Theadditionofanythingthatmayinterferewiththenormaloperationoftheappliancewithoutexpresswrittenpermissionfromthe
manufacturerorhisagentcouldinvalidatetheappliancewarranty.InGBthiscouldalsoinfringetheGasSafety(InstallationandUse)
Regulations.
WarningChecktheinformationonthedataplateiscompatiblewithlocalsupplyconditions.

AllGasSaferegisteredengineerscarryanIDcardwiththeirlicencenumberandaphotograph.Youcancheckyourengineerisregistered
bytelephoning08004085500oronlineatwww.gassaferegister.co.uk
TheboilermeetstherequirementsofStatutoryInstrument"TheBoiler(Efficiency)Regulations1993No3083"andisdeemedtomeetthe
requirementsofDirective92/42/EEContheenergyefficiencyrequirementsfornewhotwaterboilersfiredwithliquidorgaseousfuels:
TypetestforpurposeofRegulation5certifiedby:
NotifiedBody0085.
Product/Productioncertifiedby:
NotifiedBodies0085&0086.
ForGB/IEonly.
Legislation
Thiscompanydeclarethatnosubstancesharmfultohealtharecontained
intheapplianceorusedduringappliancemanufacture.
TheapplianceissuitableonlyforinstallationinGBandIEandshouldbeinstalledinaccordancewiththerulesinforce,andonly
usedinasuitablyventilatedlocation.
InGB,theinstallationmustbecarriedoutbyaGasSafe
RegisteredInstaller.Itmustbecarriedoutinaccordancewiththerelevantrequirementsofthe:
GasSafety(Installation&Use)Regulations.
TheappropriateBuildingRegulationseitherTheBuildingRegulations,TheBuildingRegulations(Scotland),BuildingRegulations
(NorthernIreland).
TheWaterFittingsRegulationsorWaterByelawsinScotland.
TheCurrentI.E.E.WiringRegulations.
Wherenospecificinstructionsaregiven,referenceshouldbemadetotherelevantBritishStandardCodeofPractice.
InIE,theinstallationmustbecarriedoutbyacompetentPersonandinstalledinaccordancewiththecurrenteditionofI.S.813'Domestic
GasInstallations',thecurrentBuilding
RegulationsandreferenceshouldbemadetothecurrentETCIrulesforelectricalinstallation.
Allsystemsmustbethoroughlyflushedandtreatedwithinhibitor(seesection6.2).
CodesofPracticerefertothemostrecentversion
InGBthefollowingCodesofPracticeapply:
Standard Scope
BS6891 GasInstallation.
BS5546 Installationofhotwatersuppliesfordomesticpurposes.
BSEN12828 Heatingsystemsinbuildings.
BSEN14336 Installation&commissioningofwaterbasedheatingsystems.
BS6798 Installationofgasfiredhotwaterboilers.
BS5440Part1 Flues.
BS5440Part2 Ventilation.
BS7074 Expansionvesselsandancillaryequipmentforsealedwatersystems.
BS7593 Treatmentofwaterindomestichotwatercentralheatingsystems.
InIEthefollowingCodesofPracticeapply:
Standard Scope
I.S.813 DomesticGasInstallations.
Thefollowingstandardsgivevaluableadditionalinformation;
BS5546 Installationofhotwatersuppliesfordomesticpurposes.
BSEN12828 Heatingsystemsinbuildings.
BSEN14336 Installation&commissioningofwaterbasedheatingsystems.
BS7074 Expansionvesselsandancillaryequipmentforsealedwatersystems.
BS7593 Treatmentofwaterindomestichotwatercentralheatingsystems.
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SafeManualHandling
General

Thefollowingadviceshouldbeadheredto,fromwhenfirsthandlingtheboilertothefinalstagesofinstallation,andalsoduring
maintenance.
Mostinjuriesasaresultofinappropriatehandlingandliftingaretotheback,butallotherpartsofthebodyarevulnerable,particularly
shoulders,armsandhands.
Health&SafetyistheresponsibilityofEVERYONE.
Thereisno'safe'limitforonemaneachpersonhasdifferentcapabilities.TheboilershouldbehandledandliftedbyTWOPEOPLE.
Donothandleorliftunlessyoufeelphysicallyable.
WearappropriatePersonalProtectionEquipmente.g.protectivegloves,safetyfootwearetc.
Preparation
Coordinatemovementsknowwhere,andwhen,youarebothgoing.
Minimisethenumberoftimesneededtomovetheboilerplanahead.
Alwaysensurewhenhandlingorliftingtherouteisclearandunobstructed.Ifpossibleavoidsteps,wetorslipperysurfaces,unlitareasetc.
andtakespecialcareonladders/intolofts.
Technique
Whenhandlingorliftingalwaysusesafetechniqueskeepyourbackstraight,bendyourknees.Don'ttwistmoveyourfeet,avoid
bendingforwardsandsidewaysandkeeptheloadasclosetoyourbodyaspossible.
Wherepossibletransporttheboilerusingasacktruckorothersuitabletrolley.
Alwaysgriptheboilerfirmly,andbeforeliftingfeelwheretheweightisconcentratedtoestablishthecentreofgravity,repositioningyourself
asnecessary.Seethe'Installation'sectionoftheseinstructionsforrecommendedliftpoints.
Remember
Thecircumstancesofeachinstallationaredifferent.Alwaysassestherisksassociatedwithhandlingandliftingaccordingtotheindividual
conditions.
IfatanytimewheninstallingtheboileryoufeelthatyoumayhaveinjuredyourselfSTOP!!
DONOT'workthrough'thepainyoumaycausefurtherinjury.
IFINANYDOUBTDONOTHANDLEORLIFTTHEBOILEROBTAINADVICEORASSISTANCEBEFOREPROCEEDING!!
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CONTENTS
1.0Introduction
2.0GeneralLayout
3.0ApplianceOperation
4.0TechnicalData
5.0DimensionsandFixings
6.0SystemDetails
7.0SiteRequirements
8.0FlueOptions
9.0PlumeDisplacement
10.0Installation
11.0Commissioning
12.0Completion
13.0Servicing
14.0ChangingComponents
15.0SettingtheGasValve
16.0Electrical
17.0ShortPartsList
18.0FaultFinding
BenchmarkChecklist
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1.0Introduction
1.1Description
1.TheBaxiDuotecCombiHEAisafullyautomaticgasfiredwallmountedcondensingcombinationboiler.Itisroomsealedandfan
assisted,andwillservecentralheatingandmainsfeddomestichotwater.
2.Theboilerissettogiveamaximumoutputof:
24models 24kWDHW
 21kWCH(Condensing)
28models 28kWDHW
25.9kWCH(Condensing)
33models 33kWDHW
 30.3kWCH(Condensing)
40models 40kWDHW
 34.4kWCH(Condensing)
3.ItisdesignedforuseonNaturalGas(G20).
4.Theboilerissuitableforuseonlyonfullypumpedsealedheatingsystems.Priorityisgiventodomestichotwater.
5.Theboilerdatabadgegivesdetailsofthemodel,serialnumberandGasCouncilnumberandissituatedontheinnerdoorpanel.Itis
visiblewhenthecasefrontpanelisremoved(Fig.1).
6.Theboilermodelnameandserialnumberarealsoshownontheinformationlabelontheundersideofthefacia.Thisisforuser
reference.
7.Theboilerisintendedtobeinstalledinresidential/commercial/lightindustrialE.M.C.environmentsonagovernedmetersupply
only.
8.Theboilermustbeinstalledwithoneofthepurposedesignedfluessuchasthestandardhorizontaltelescopicfluekit,partno.
5118069.
9.Allsystemsmustbethoroughlyflushedandtreatedwithinhibitor(seesection6.2).
Fig.1
Important:Iftheboilerisinstalledatahighpointinthesystemitisstrongly
recommendedthatAutomaticAirVentKit720004701isfitted.
1.2OptionalExtras
Integraltimers,RFroomthermostatsetc.areavailableasoptionalextras.
1.3ContentsofPack

Thepackcontains:
Boiler
WallPlate(includingtaps)
SetofPipeConnections
Template&'QuickFit'Guide
LiteraturePack
FillingLoop
page7
2.0GeneralLayout
2.1Layout

1. ExpansionVessel
2. AutomaticAirVent
3. DHWPlateHeatExchanger
4. CirculationPump
5. DrainOffPoint
6. PressureReliefValve
7. SelectorSwitch
8. CentralHeatingSystemPressureGauge
9. PCB
10. ControlBox
11. 3WayValveAssembly
12. CondensateTrap
13. FlameSensingElectrode
14. SparkElectrode
15. PrimaryHeatExchanger
16. FanAssembly
17. On/Off/ResetSelectorSwitch
18. CentralHeatingTemperatureControl
19. HotWaterTemperatureControl
20. Venturi
21. Air/GasCollector
22. CombustionBoxCover&Burner
23. Igniter
24. BurnerOnLight
25. CentralHeatingModeLight
26. DomesticHotWaterModeLight
27. Display
28. PositionofOptionalIntegralTimer

page8
3.0ApplianceOperation
3.1CentralHeatingMode(Fig.2)

1.Withademandforheating,thepumpcirculateswaterthroughtheprimarycircuit.
2.Oncemainburnerignitesthefanspeedcontrolsthegasratetomaintaintheheatingtemperaturemeasuredbythetemperature
sensor.
3.Whentheflowtemperatureexceedsthesettingtemperature,a3minutedelayoccursbeforetheburnerrelightsautomatically(anti
cycling).Thepumpcontinuestorunduringthisperiod.
4.Whenthedemandissatisfiedtheburnerisextinguishedandthepumpcontinuestorunforaperiodof3minutes(PumpOverrun).
CentralHeatingCircuit
Fig.2
Key
1 PrimaryHeatExchanger 14 GasInlet
2 Burner 15 DomesticHotWaterOutlet
3 IgnitionElectrodes 16 HeatingFlow
4 FlameSensingElectrode 17 PressureGauge
5 GasValve 18 WaterPressureSensor
6 Pump 20 Fan
7 AutomaticAirVent 21 DiverterValveAssembly
8 PlateHeatExchanger/AutomaticBypass 22 DiverterValveMotor
9 FlowSensorwithFilter&Regulator 23 DomesticHotWaterFlowTemperatureSensor
10 PressureReliefValve 24 SafetyThermostat
11 BoilerDrainPoint 25 CentralHeatingTemperatureSensor
12 HeatingReturn 26 ExpansionVessel
13 ColdWaterInletOn/OffValveandFilter  
3.2DomesticHotWaterMode(Fig.3)
1.Priorityisgiventothedomestichotwatersupply.Ademandatataporshowerwilloverrideanycentralheatingrequirement.
2.TheflowofwaterwilloperatetheHallEffectSensorwhichrequeststhe3wayvalvetochangeposition.Thiswillallowthepumpto
circulatetheprimarywaterthroughtheDHWplateheatexchanger.
3.Theburnerwilllightautomaticallyandthetemperatureofthedomestichotwateriscontrolledbythetemperaturesensor.
4.Whenthedomestichotwaterdemandceasestheburnerwillextinguishandthedivertervalvewillremaininthedomestichotwater
mode,unlessthereisademandforcentralheating.
DomesticHotWaterCircuit

Fig.3

IMPORTANT:Whentheselectorswitchisinthe'0'(Off)positiontheelectricalsupplytotheboilerisisolated.
Theboilerwillnotoperateandtheintegraltimerwillrequireresettingoncetheselectorswitchissettoeither
Position(i)orPosition(ii).
3.3FrostProtectionMode
1.Thefrostprotectionmodeisintegraltotheapplianceandfunctionsonlywiththeselectorswitch(seeSection2.1)inthedomestic
hotwaterandcentralheatingposition.Ifthesystemtemperaturefallsbelow5°Cthentheboilerwillfireonitsminimumsettinguntil
aflowtemperatureof30°Cisreached.Furtherprotectioncanbeincorporatedbyusingasystemfrostthermostat.
3.4PumpProtection
1.Withtheselectorswitch(seeSection2.1)ineitherthecentralheatingorcentralheatinganddomestichotwaterposition,thepump
willautomaticallyoperatefor1minuteinevery24hourstopreventsticking.
page9
4.0TechnicalData
4.1DuotecCombi24,28,33&40HEA

ApplianceType C13 C33 C53
ApplianceCategory  CATI2H 
HeatInputCH (Net) Max Min
24model kW 20.5 7
28model kW 24.7 9
33model kW 28.9 9.7
40model kW 32.8 9.9
HeatInputCH(Gross) Max Min
24model kW 22.7 7.8
28model kW 27.4 10
33model kW 32.1 10.8
40model kW 36.4 11
   
HeatOutputCH (NonCondensing) Max Min
24model kW 20 6.8
28model kW 24 8.7
33model kW 28 9.4

40model kW 32 9.6
   
HeatOutputCH (Condensing) Max Min
24model kW 21 7.4
28model kW 25.9 9.5
33model kW 30.3 10.2
40model kW 34.4 12.1
HeatInputDHW (Net) Max 
24model kW 24.7 
28model kW 28.9 
33model kW 34 
40model kW 41.2 
HeatInputDHW (Gross) Max 
24model kW 27.4 
28model kW 32.1 
33model kW 37.7 
40model kW 45.7 
HeatOutputDHW  Max 
24model kW 24 
28model kW 28 
33model kW 33 
40model kW 40 
MaxGasRate (Natural(After10GasG20)mins)
24model m3/h 2.61 
28model m3/h 3.1 
33model m3/h 3.6 
40model m3/h 4.36 
SEDBUKDeclaration
Theefficiencyforallmodelsis91.1%
ThisvalueisusedintheUKGovernment's
StandardAssessmentProcedure(SAP)forenergyratingofdwellings.
Thetestdatafromwhichithasbeencalculatedhasbeencertifiedby0087.

InletPressure(NaturalGasG20) mbar20
Injector(NaturalGasG20) 7.5mm(24&28)12mm(33&40)
ElectricalSupply230V~50Hz 
(Appliancemustbeconnectedtoanearthedsupply)
PowerConsumption 155W 160W
 (24,28) (33&40)
ElectricalProtection 
 IPX0D(withtimer)
 IPX5D(withouttimer)
ExternalFuseRating 3A
InternalFuseRating F2L
CondensateDrain Toaccept21.5mm(3/4in)plasticwastepipe
FlueTerminalDimensions Diameter 100mm
 Projection 125mm
Connections coppertails
GasSupply 22mm
CentralHeatingFlow 22mm
CentralHeatingReturn 22mm
ColdWaterMainsInlet 15mm
DHWFlow 15mm
PressureReliefDischarge 15mm
OutercaseDimensions 
CasingHeight 780mm

OverallHeightIncFlueElbow 965mm
CasingWidth 450mm
CasingDepth 345mm
Clearances 
AboveCasing 200mmMin
BelowCasing 150mmMin*
Front 450mmMin(ForServicing)
Front 5mmMin(InOperation)
L.H.Side 5mmMin
R.H.Side 5mmMin(InOperation)
*ThisisMINIMUMrecommendeddimension.Greaterclearancewillaidinstallationandmaintenance.
Weights 
(24model)
PackagedBoilerCarton 48.6kg
InstallationLiftWeight 43.6kg
(28model)
PackagedBoilerCarton 49.2kg
InstallationLiftWeight 44.2kg
(33&40model)
PackagedBoilerCarton 51kg
InstallationLiftWeight 46kg

NOxClass 5   
CentralHeatingPrimaryCircuit
Pressures
bar   
SafetyDischarge 3   
MaxOperating 2.5   
MinOperating 0.5   
RecommendedOperatingRange 12   
DHWCircuitPressures bar   
MaxOperating 8   
MinOperating 0.15   
FlowRates (24) (28) (33) (40)
DHWFlowRate l/min l/min l/min l/min
@30oCRise 11.43 13.3 15.7 19.1
DHWFlowRate
@35oCRise 9.8 11.5 13.5 16.4
MinWorkingDHWFlowRate 2 2 2 2
IMPORTANT:WhereLowFlowTapsorFittingsareintendedtobeusedintheDHWsystemconnected
itisstronglyrecommendedthattheDHWflowrateDOESNOTfallbelow2.5l/min.
ThiswillensurereliableoperationoftheDHWfunction.
Pump AvailableHeadSeegraphbelow
ExpansionVessel (ForCentralHeatingonly.Integralwithappliance)
MinPrechargePressure 0.5bar  
 (24&28) (33&40)  
 litre litre  
MaxCapacityofCHSystem 125 155  
PrimaryWaterContentofBoiler (unpressurised)  
 litre litre  
 2.5 2.8  
Temperatures    
C.H.FlowTemp(adjustable) 25°Cto80°Cmax(±5°C) 
D.H.W.FlowTemp(adjustable) 35°Cto60°Cmax(±5°C) 
 dependentuponflowrate  
NOTE:Alldatainthissectionarenominalvaluesand
subjecttonormalproductiontolerances.
PumpAvailableHead

page10
5.0DimensionsandFixings
Dimensions
A780mm
B345mm
C450mm
D116mmØMin.
E185mm
 (207mmfor80/125mmfluesystems)
F145mm
G131mm
H180mm
J270mm

page11
6.0SystemDetails
6.1Information
1.TheBaxiDuotecCombiHEACondensingCombinationBoilerisa'WaterByelawsSchemeApprovedProduct'.Tocomplywith
theWaterByelawsyourattentionisdrawntothefollowinginstallationrequirementsandnotes(IRN).
a)IRN001Seetextofentryforinstallationrequirementsandnotes.
b)IRN302Byelaw14.
2.ReferencetotheWRcpublications,'Waterfittingsandmaterialsdirectory'and'Watersupplybyelawsguide'givefulldetailsof
byelawsandtheIRNs.

6.2CentralHeatingCircuit
1.TheapplianceissuitableforfullypumpedSEALEDSYSTEMSONLY.
TreatmentofWaterCirculatingSystems
Allrecirculatorywatersystemswillbesubjecttocorrosionunlessanappropriatewatertreatmentisapplied.Thismeansthatthe
efficiencyofthesystemwilldeteriorateascorrosionsludgeaccumulateswithinthesystem,riskingdamagetopumpandvalves,
boilernoiseandcirculationproblems.
Whenfittingnewsystemsfluxwillbeevidentwithinthesystem,whichcanleadtodamageofsystemcomponents.
Allsystemsmustbethoroughlydrainedandflushedoutusing,forexample,SentinelX300orX400orFernoxF3.Theyshouldbe
usedfollowingtheflushingagentmanufacturer'sinstructions.
Systemadditivescorrosioninhibitorsandflushingagents/descalersshouldcomplytoBS7593requirements,e.g.SentinelX100
andFernoxMB1whichshouldbeusedfollowingtheinhibitormanufacturer'sinstructions.
Fullinstructionsaresuppliedwiththeproducts,forfurtherinformationcontactSentinel(08003894670)orFernox(08708700362)
Failuretoflushandaddinhibitortothesystemwillinvalidatetheappliancewarranty.
Itisimportanttochecktheinhibitorconcentrationafterinstallation,systemmodificationandateveryserviceinaccordancewiththe
manufacturer'sinstructions.(Testkitsareavailablefrominhibitorstockists.)
ForinformationoradviceregardinganyoftheabovecontactTechnicalEnquiries.
6.3Bypass
1.TheboilerutilisestheprimarysideoftheDHWplateheatexchangerasanautomaticintegralbypass.
6.4SystemControl
1.Furtherexternalcontrols(e.g.roomthermostat)shouldbefittedtooptimisetheeconomicaloperationoftheboiler.
page12
6.5SystemFillingandPressurising
1.Afillingpointconnectiononthecentralheatingreturnpipeworkmustbeprovidedtofacilitateinitialfillingandpressurisingandalso
anysubsequentwaterlossreplacement/refilling.
Afillingloop&instructionsareprovidedwiththeboiler
2.Thefillingmethodadoptedmustbeinaccordancewithallrelevantwatersupplyregulationsanduseapprovedequipment.
3.Yourattentionisdrawnto:forGB:GuidanceG24.2andrecommendationR24.2oftheWaterRegulationsGuide.forIE:thecurrent
editionofI.S.813"DomesticGasInstallations".
4.Thesealedprimarycircuitsmaybefilledorreplenishedbymeansofatemporaryconnectionbetweenthecircuitandasupplypipe,
provideda'Listed'doublecheckvalveorsomeothernolesseffectivebackflowpreventiondeviceispermanentlyconnectedatthe
inlettothecircuitandthetemporaryconnectionisremovedafteruse.
IMPORTANT:Iftheboilerisinstalledatahighpointinthesystemitisstronglyrecommended
thatAutomaticAirVentKit720004701isfitted.
Fig.4

Fig.5
6.6ExpansionVessel(CentralHeatingonly)
1.Theapplianceexpansionvesselisprechargedto0.5bar.Therefore,theminimumcoldfillpressureis0.5bar.Thevesselis
suitableforcorrectoperationforsystemcapacitiesupto125litres.Forgreatersystemcapacitiesanadditionalexpansionvessel
mustbefitted.ForGBrefertoBS7074Pt1.ForIE,thecurrenteditionofI.S.813"DomesticGasInstallations".
6.7SafetyPressureReliefValve(Fig.6)
1.Thepressurereliefvalveissetat3bar,thereforeallpipework,fittings,etc.shouldbesuitableforpressuresinexcessof3barand
temperatureinexcessof100°C.
2.Thepressurereliefdischargepipeshouldbenotlessthan15mmdia,runcontinuouslydownward,anddischargeoutsidethe
building,preferablyoveradrain.Itshouldberoutedinsuchamannerthatnohazardoccurstooccupantsorcausesdamageto
wiringorelectricalcomponents.Theendofthepipeshouldterminatefacingdownandtowardsthewall.
3.Thedischargemustnotbeaboveawindow,entranceorotherpublicaccess.Considerationmustbegiventothepossibilitythat
boilingwater/steamcoulddischargefromthepipe.
4.Aremotereliefvalvekitisavailabletoenabletheboilertobeinstalledincellarsorsimilarlocationsbelowoutsidegroundlevel(kit
no.5121379).
Fig.6
page13
6.8DomesticHotWaterCircuit(Fig.7)
1.AllDHWcircuits,connections,fittings,etc.shouldbefullyinaccordancewithrelevantstandardsandwatersupplyregulations.

2.Yourattentionisdrawnto:
forGB:GuidanceG17toG24andrecommendationR17toR24oftheWaterRegulationsGuide.
forIE:thecurrenteditionofI.S.813"DomesticGasInstallations".
3.TheWaterRegulationsrecommendationsforEnglandandWalesprohibitsbackflowfromappliancesintothewholesomewater
supplyduetothermalexpansion.Howeverthistypeofinstantaneouscombinationboiler,withlessthan15litresofstoredcapacity,
doesnotrequireanybackflowpreventiondeviceasanythermalexpansionisaccommodatedwithintheappliance.Itispossiblein
certaincircumstancesthatothercoldwaterdemands(e.g.washingmachines,flushingofW.C.s)mayaffecttheDHWfunctionof
theboiler.Intheseinstancesthefittingofabackflowpreventiondeviceandexpansionvesselisrecommended.
4.Alsoifthereisanexistingcheckvalve,loosejumperedstopcock,watermeterorwatertreatmentdevicealreadyfittedtothe
wholesomewatersupplyconnectedtotheboilerdomestichotwater(DHW)inletsupplythenasuitableexpansiondevicemaybe
required.
5.Theboiler'smaximumworkingmainspressureis8bar,thereforeallpipework,connections,fittings,etc.shouldbesuitablefor
pressuresinexcessof8bar.Apressurereducingvalvemustbefittedforpressuresinexcessof8bar.Themanufacturerofany
outletfittings,suchasashowervalve,mayrequirealowermaximumpressure.Thepressurereductionmusttakeaccountofall
fittingsconnectedtotheDHWsystem.
Fig.7
6.9Showers
1.Ifashowercontrolissuppliedfromtheapplianceitshouldbeofthethermostaticorpressurebalancedtype.Thermostatictype
showervalvesprovidethebestcomfortandguardagainstwaterattoohighatemperature.Existingcontrolsmaynotbesuitable
refertotheshowervalvemanufacturer.
6.10HardWaterAreas
1.IftheareaoftheinstallationisrecognisedasaHARDWATERAREAthenasuitabledeviceshouldbefittedtotreatthemains
watersupplytotheboiler.ContactyourWaterDistributionCompanyforadviceonsuitabledevices.
page14
7.0SiteRequirements
7.1Location
1.Theboilermaybefittedtoanysuitablewallwiththefluepassingthroughanoutsidewallorroofanddischargingtoatmosphereina
positionpermittingsatisfactoryremovalofcombustionproductsandprovidinganadequateairsupply.Theboilershouldbefitted
withinthebuildingunlessotherwiseprotectedbyasuitableenclosurei.e.garageorouthouse.(Theboilermaybefittedinsidea
cupboardseeSection7.3).
2.IftheboilerissitedinanunheatedenclosurethenitisrecommendedtoleavetheON/OFFSelectorSwitchinthedomestichot
waterandcentralheatingpositiontogivefrostprotection.
3.Iftheboilerisfittedinaroomcontainingabathorshowerreferencemustbemadetotherelevantrequirements.InGBthisisthe
currentI.E.E.WiringRegulationsandBuildingRegulations.InIEreferenceshouldbemadetothecurrenteditionofI.S.813
"DomesticGasInstallations"andthecurrentETCIrules.
4.IftheboileristobefittedintoabuildingoftimberframeconstructionthenreferencemustbemadetothecurrenteditionofInstitute
ofGasEngineersPublicationIGE/UP/7(GasInstallationsinTimberFramedHousing).
*ThisistheMINIMUMrecommendeddimension.Greaterclearancewillaidinstallationandmaintenance.

Fig.8
Fig.9
7.2Clearances(Figs.8&9)
1.Aflatverticalareaisrequiredfortheinstallationoftheboiler.

2.Thesedimensionsincludethenecessaryclearancesaroundtheboilerforcaseremoval,spanneraccessandairmovement.Additional
clearancesmayberequiredforthepassageofpipesaroundlocalobstructionssuchasjoistsrunningparalleltothefrontfaceoftheboiler.
page15
7.3VentilationofCompartments
1.Wheretheapplianceisinstalledinacupboardorcompartment,noairventsarerequired.
2.BS5440:Part2referstoroomsealedappliancesinstalledincompartments.Theappliancewillrunsufficientlycoolwithout
ventilation.
7.4GasSupply
1.Thegasinstallationshouldbeinaccordancewiththerelevantstandards.InGBthisisBS6891.InIEthisisthecurrenteditionof
I.S.813"DomesticGasInstallations".
2.Theconnectiontotheapplianceisa22mmcoppertaillocatedattherearofthegasservicecock(Fig.10).
3.Ensurethatthepipeworkfromthemetertotheapplianceisofadequatesize,andthedemandsofanyothergasappliancesinthe
propertyaretakenintoconsideration.Donotusepipesofasmallerdiameterthantheboilergasconnection(22mm).
Fig.10
7.5ElectricalSupply
1.Externalwiringmustbecorrectlyearthed,polarisedandinaccordancewithrelevantregulations/rules.
InGBthisisthecurrentI.E.E.WiringRegulations.InIEreferenceshouldbemadetothecurrenteditionofETCIrules.
2.Themainssupplyis230V~50Hzfusedat3A.
NOTE:Themethodofconnectiontotheelectricitysupplymustfacilitatecomplete
electricalisolationoftheappliance
Connectionmaybeviaafuseddoublepoleisolatorwithacontactseparationofat
least3mminallpolesandservicingtheboilerandsystemcontrolsonly
Fig.A
7.6Bath&ShowerRooms

1.IftheboilerisfittedinaroomcontainingabathorshowerandNOTFITTEDwithanyoptionalintegraltimerorthermostat,itcanbe
fittedinzone2,(Figs.A&Bshowszonedimensionsforabathtub.ForotherexamplesrefertotheCurrentI.E.E.Wiring
Regulations)referencemustbemadetotherelevantrequirements.
InGBthisisthecurrentI.E.E.WiringRegulationsandBuildingRegulations.
InIEreferenceshouldbemadetothecurrenteditionofI.S.813"DomesticGasInstallations"andthecurrentETCIrules.
Fig.B
page16
7.7CondensateDrain
FAILURETOINSTALLTHECONDENSATEDISCHARGEPIPEWORKCORRECTLY
WILLAFFECTTHERELIABLEOPERATIONOFTHEBOILER.
CAREFULCONSIDERATIONMUSTBEGIVENTOTHEPOSSIBILITYOFTHE
PIPEWORKBEINGSUBJECTTOFREEZINGCONDITIONSANDAPPROPRIATE
MEASURESTAKENTOPREVENTBLOCKAGE.CORRECTINSTALLATIONIN
ACCORDANCEWITHTHISSECTIONWILLCONSIDERABLYMINIMISETHE
LIKELIHOODOFBLOCKAGEANDSUBSEQUENTBOILERLOCKOUT.
ACONDENSATEDISCHARGEPUMPANDPIPE'TRACEHEATING'ARE
AVAILABLEASACCESSORIESseeparagraphs7.7.12to7.715forfurtherdetails.
ThecondensatedischargepipeMUSTNOTRISEatanypointalongitslength.
ThereMUSTbeafallofATLEAST2.5°(50mmpermetre)alongtheentirerunEXCEPT
whenemployingasuitablecondensatepumpinbasementandcellarorsimilarapplications.
Theboilercondensatetrapincorporatesasealof75mm,thereforeitisunnecessaryto
installanairbreakandtrapinthedischargepipework.
1.Thecondensateoutletwillaccept21.5mm(3/4in)plasticoverflowpipe.Itisstronglyrecommendedthatthisdischarges
internallyintothehouseholddrainagesystem.Wherethisisnotpossible,dischargeintoanoutsidedrainispermissible
providingeverypossibleprecautionistakentopreventfreezing.
2.Ensurethedischargeofcondensatecomplieswithanynationalorlocalregulationsinforce.BS6798&PartH1oftheBuilding
Regulationsgivefurtherdetailedguidance.
3.Thedischargepipeshouldberuninaproprietarydrainpipemateriale.g.PVC,PVCU,ABS,PVCCorPP.
4.MetalpipeworkisNOTsuitableforuseincondensatedischargesystems.
5.Thepipeshouldbeaminimumof21.5mmdiameterandmustbesupportedusingsuitablyspacedclipsofthecorrectdesignto
preventsagging.
6.Itisadvisablethatthefulllengthofcondensatepipeisruninternallyandpreferablybelessthan3metres.
7.Internalrunsgreaterthan3metresorrunsincoldareasshoulduse32mmwastepipe.
8.ExternalrunsMUSTbeaMINIMUMof32mmandfullyinsulatedwithmaterialsuitableforexternaluse.
9.Iftheboilerisfittedinanunheatedlocationtheentirecondensatedischargepipeshouldbetreatedasanexternalrunandsizedand
insulatedaccordingly.
10.Inallcasesdischargepipemustbeinstalledtoaiddisposalofthecondensate.Toreducetheriskofcondensatebeingtrapped,as
fewbendsandfittingsaspossibleshouldbeusedandanyburrsoncutpiperemoved.
Examplesareshownofthefollowingmethodsoftermination:
i)toaninternalsoil&ventpipe
ii)viaaninternaldischargebranch(e.g.sinkwaste)downstreamofthetrap
iii)toadrainorgully
iv)toapurposemadesoakaway