Ideal Boilers mini HE C24 User manual

installation and
servicing
miniHE
Whenreplacing anypartofthisappliance,useonlysparepartsthatyoucanbeassured
conformtosafetyand performancespecificationthatwerequire.Donotuse
reconditionedorcopypartsthathavenotbeenclearlyauthorised byIdealBoilers
Fordetailsofdocumentamendments,refertopage3
YourIdeal installation and servicing guide
Forusersguidesee reverseofbook
Fortheverylatestcopyofliteratureforspecificationpurposespleasevisitourwebsite
www.idealboilers.comwhereyouwill beabletodownload therelevantinformationinpdf format.
17962.1138.1 0406 64A4GB
*1796211381*
C24,C28

2miniHE --- Installation&Servicing

miniHE --- Installation&Servicing3
DOCUMENTAMENDMENTS
RelevantInstallationchangesimplementedinthisbookfromModLevel.............4905 to0406
FPages33 and37
Amendment totheillustrationoftheairpressureswitchconnection
CaradonIdealLimitedreservetheright tovaryspecificationwithoutnotice

GENERAL
4miniHE --- Installation&Servicing
Table1--- BoilerData
miniHEC24 miniHEC28
Gas supplytype&connectionII2H3PG20 20mbar,G31 37mbar,22 mm copper
Inlet/Outletconnection--- DomesticHotWater15 mm copper
Flow&returnconnection--- CentralHeating22 mm copper
Flueterminaldiametermm (in.)100 (4)
Maxworkingpressure(sealedsystem)bar(lb/in2)3.0(43.5)
MaxDHWwaterinletpressurebar(lb/in2)10.0(145.0)
MinDHWwaterinletpressurebar(lb/in2)0.3(4.4)
Electricalsupply230 Vac50 Hz
MaxpowerconsumptionW140 150
Externalfuserating3A
InternalfuseratingT2A
Watercontent--- CHlitre(gal.)2.1(0.46)2.2(0.48)
Watercontent--- DHWlitre(gal.)0.2(0.044)
Dryweightkg(lb.)42.5(93.7)44.5(98.1)
Size:Height/Width/Depthmm (in.)803 (31 5/8”)/400 (15 3/4”)/345 (13 9/16”)
Liftweightkg(lb.)37.5(82.7)39.5(87.1)
Table2--- PerformanceData--- CentralHeating
miniHEC24 miniHEC28
MaxMinMaxMin
Burnerpressure(Hot)G20
G31
mbar(in.w.g.)10.8(4.3)
35.5(14.2)
1.5(0.6)
7.7(3.1)
10.0(4.0)
36.0(14.4)
1.6(0.6)
7.7(3.1)
Inputbasedon nett CVkW(btu/h)25.0(85 295)11.0(37 530)29.0(98 942)13.0(44 353)
Inputbasedongross CVkW(btu/h)27.7(94 516)12.2(41 628)32.2(109 871)14.4(49 135)
OutputNonCondensingG20
G31
kW(btu/h)24.6(83 973)
23.7(80 894)
10.2(34 936)
10.2(34 936)
28.3(96 488)
27.4(93 599)
12.1(41 284)
12.1(41 284)
OutputCondensingG20
G31
kW(btu/h)26.6(90 754)
26.6(90 754)
11.1(37 871)
10.8(36 997)
30.7(104 602)
30.7(104 602)
13.2(44 965)
12.9(44 016)
Gasconsumption(Hot)G20
G31
l/s(ft3/h)
l/s
0.74 (93.6)
0.30
0.32 (40.9)
0.13
0.85 (108.4)
0.34
0.35 (45.2)
0.14
Seasonalefficiency*G20
G31
(SEDBUK)%BandB87.7
BandB86.9
BandB87.5
BandB87.0
NOxclassificationClass 2
*ThevalueisusedintheUKGovernment’sStandardAssessmentProcedure(SAP)forenergyratingofdwellings.
Thetestdatafromwhichithasbeencalculatedhavebeencertified byanotified body.
Table3--- PerformanceData--- DomesticHotWater
miniHEC24 miniHEC28
Maximum
Burnerpressure(Hot)G20
G31
mbar(in.w.g.)10.8(4.3)
35.5(14.2)
10.0(4.0)
36.0(14.4)
Inputbasedon nett CVkW(btu/h)25.0(85 295)29.0(98 942)
Inputbasedongross CVkW(btu/h)27.7(94 516)32.2(109 871)
OutputNonCondensingG20
G31
kW(btu/h)24.6(83 973)
23.7(80 894)
28.3(96 488)
27.4(93 599)
OutputCondensingG20
G31
kW(btu/h)26.6(90 754)
26.6(90 754)
30.7(104 602)
30.7(104 602)
Gasconsumption(Hot)G20
G31
l/s(ft3/h)
l/s
0.74 (93.6)
0.30
0.85 (108.4)
0.34
Flow35 °Ctemp.risel/m(gpm)10.1(2.2)11.7(2.6)
Domestichotwaterspecificratel/m(gpm)11.9(2.6)13.9(3.1)
Note:thegasconsumptioniscalculatedusingacalorific
valueof38.7MJ/m3(1038 Btu/ft3)gross or34.9MJ/m3(935
Btu/ft3)nett.
To obtainthegasconsumptionatdifferentcalorificvalue:---
a.FORL/S--- dividethegross heatinput(kW)bythegross
C.V.ofthegas(MJ/m3)
b.FORFT3/H--- dividethegross heatinput(Btu/h)bythe
gross C.V.ofthegas(Btu/ft3)
KeytoSymbols:
IE=Ireland,GB=UnitedKingdom(Countriesofdestination)
PMS=Maximumoperatingpressureofwater
C12 C32 C42 =aroomsealedappliancedesignedfor
connectionviaconcentricductstoahorizontalorvertical
terminalortwinfluesystem.
II2H3P=appliancedesignedforuseon2ndfamilygasgroup
Hor3rdfamilygasgroup3P
CAUTION. Toavoidthepossibilityofinjuryduringtheinstallation,servicingorcleaning
ofthisappliancecareshould betakenhandling edgesofsheetsteelcomponents.

GENERAL
miniHE --- Installation&Servicing5
miniHE
BoilersizeG.C.applianceNo.PINo.
(BenchmarkNo.)
miniHEC24 47---348---38 0694BP0384
miniHEC28 47---348---39 0694BP0384
Destinationcountries:GB,IE
CONTENTS
Airsupply9
BenchmarkCommissioningChecklist58
Boilerclearances6
Boilerexplodedview14
Electricalconnections20
Electricalsupply10
Faultfinding48
Flow wiringdiagram24
Fluefitting16
Gasconversion29
Gas safetyregulations7
Gas supply8
Installation15
Mandatoryrequirements7
Replacementofcomponents34
Safehandling7
Servicing30
Shortlistofparts55
Thermostaticradiatorvalves12
Waterconnections19
Watertreatment9
Wiringdiagrams22
ForGB,tocomplywithBuildingRegulationsPartL1(PartJinScotland)theboilershould befittedinaccordancewiththe
manufacturer’sinstructions.Self---certificationthat theboilerhasbeeninstalledtocomplywithBuildingRegulationscanbe
demonstrated bycompletingandsigningtheBenchmarkCommissioningChecklist.
BENCHMARKCOMMISSIONINGCHECKLISTDETAILS
BoilerPage
Makeandmodel5
Applianceserialno.ondatabadge14
SEDBUKNo.%4
Controls
Timeandtemperaturecontroltoheating26
Timeandtemperaturecontroltohotwater26
Heatingzonevalves26
TRV’s12
Autobypass 12
Boilerinterlock12
Forall boilers
FlushingtoBS.7593 9
Inhibitor9
Centralheatingmode
Heatinput tobecalculated
BoilerPage
Burneroperatingpressuremeasureandrecord
Centralheatingflowtemp.measureandrecord
Centralheatingreturntemp.measureandrecord
Forcombinationboilersonly
Scalereducer12
Hotwatermode
Heatinput tobecalculated
Max.operatingburnerpressuremeasureandrecord
Max.operatingwaterpressuremeasureandrecord
Coldwaterinlet tempmeasureandrecord
Hotwateroutlet temp.measureandrecord
Waterflowrateatmax.settingmeasureandrecord
Forcondensingboilersonly
Condensatedrain20
Forall boilers:complete,sign&handovertocustomer
Forassistancesee TechnicalHelplineonthebackpage
NOTETOTHE INSTALLER:COMPLETE
THE BENCHMARKCOMMISSIONING
CHECKLISTANDLEAVETHESE
INSTRUCTIONSWITHAPPLIANCE

GENERAL
miniHE --- Installation&Servicing
6
1BOILER WATER CONNECTION
400
803 700
35
257
16
31
50
65 (2 9/16”)
83 (3 1/4”)
65 (2 9/16”) 52 (2”) 64 (2 1/2”)
CHreturn
CHflow
DHWcoldinlet*
Gasinlet
DHWhotoutlet*
Wall
mounting
Plate
Condensate
drain
connection
area
PipesizeO.D.mm
CHflow22
CHreturn22
Gasinlet22
DHWcoldinlet15
DHWhotoutlet15
2BOILER CLEARANCES
All dimensionsinmm (in.)
Thefollowingminimumclearancesmustbemaintainedfor
operationandservicing.Additionalspacewill berequiredfor
installation,dependinguponsiteconditions.
25 (1”)50 (2”)
200 (7 7/8”)
200 (7 7/8”)
Bottomclearance
Thebottomclearance,afterinstallation,canbereducedto
20mm.However,200mm mustbeavailableforservicing.
Frontclearance
Theminimumfrontclearancewhenbuiltintoacupboardis
50mm (2”)fromthecupboard door.However450mm
(17 3/4”)overall clearanceis still required,withthecupboard
dooropen,toallowforservicing.
SideandRearFlue
a.Providedthat theflueholeiscutaccurately,e.g.withacore
drill,thefluecanbeinstalledfrominsidethebuildingwhere
wall thickness doesnotexceed600 mm (24”).
Wherethespaceintowhichtheboilerisgoingtobeinstalled
isless thanthelengthof fluerequiredthefluemustbefitted
fromtheoutside.
installationfrominsideONLY
b.Ifacoreboringtoolistobeusedinsidethebuildingthe
spaceinwhichtheboileristobeinstalledmustbeatleast
wide enoughtoaccommodatethetool.
190 (7 1/2”)
95 ()
273 (10 3/4”)127 (5”)

GENERAL
miniHE --- Installation&Servicing7
INTRODUCTION
miniHEC24 and miniHEC28 arewall mounted,low water
content, balanced flue,condensingcombinationgasboilers.
Centralheating(CH)outputand domestichotwater(DHW)
outputarebothfullymodulating:
--- between10.2(34 936)and24.6*(83 973)kW(btu/h)for
modelminiHEC24;
--- between12.1(41 284)and28.3*(96 488)kW(btu/h)for
modelminiHEC28.
* ouputswithG31 (propane)feedingaresligthlydifferent.
See sectionBoilerDataatpage4fordetailedfigures.
Duetothehighefficiencyoftheboileraplumeofwater
vapourwill format theterminalduringoperation.
Theboilersaresuitableforconnectiontofullypumped,
pressurisedsealedwatersystemsONLY.
Asystembypass isnotrequiredwhenTRV’sarefittedtoall
radiators(see Frame5).Theboilerincorporatesanautomatic
bypass.
Acirculatingpump,pressuregauge,safetyvalveandheating
expansionvesselareprovided.
TheCHflowtemperatureiscontrolled byathermistor.In
DHWmodetheboilermodulatestosustainanominal
adjustablewaterflowtemperatureof55 °C.
Theboilercasingisofwhitepaintedmildsteelwitha
drop--- downcontrolsaccess door.
Theboilertemperaturecontrolislocated behindthecontrol
paneldoor.
Themain heatexchangerismadeofcopper.
Thecondensingheatexchanger(recuperator)andtheDHW
heatexchangerarestainless steel.
Thesystempipeworkmustincludedraincocksinappropriate
places.Pipeworkmaybetakendownwards.
Forupwardspipeworkinstallationanadditionalframe
(optional)mustbeused(see frame18).
OPTIONALEXTRAKITS
ProgrammerKitfitsneatlywithinthecasing.Separatefitting
instructionsareincludedwiththekit.Note.Ifusingan
alternativeprogrammer readFrame25 first.
HorizontalConcentricExtensionDucts
Upto2,7m(8’10”) forall models.
Otheravailablekitsarelistedinframe9.
SAFE HANDLING
Thisboilermayrequire2ormoreoperativestomoveit toits
installationsite,removeitfromitspackagingbaseand during
movementintoitsinstallationlocation.Maneuveringtheboiler
mayincludetheuseofasacktruckandinvolvelifting,
pushingand pulling.
Cautionshould be exercised duringtheseoperations.
Operatives should beknowledgeablein handlingtechniques
whenperformingthesetasksandthefollowingprecautions
should beconsidered:
FGriptheboilerat thebase.
FBephysicallycapable.
FUsePPEasappropriate,e.g.gloves,safetyfootwear.
Duringall maneuversandhandlingactions,everyattempt
should bemadetoensurethefollowingunless unavoidable
and/ortheweightislight.
FKeep backstraight.
FAvoidtwistingat thewaist.
FAvoidupperbody/topheavybending.
FAlwaysgripwiththepalmofthehand.
FUsedesignatedhandholds.
FKeeploadasdosetothebodyaspossible.
FAlwaysuseassistanceifrequired.
DHWOPERATION
With nocall forCHtheboilerfiresonlywhenDHWisdrawn
off.Whenthereisacall forCH,theheatingsystemis supplied
at theselectedtemperatureuntilDHWisdrawnoff.The
outputisthendirected bythedivertervalvetoheat the
secondaryheatexchangerandsupplyamaximumdraw--- off
of:
miniHEC24.10.1(2.2)l/min(gpm) at35 degree rise.
miniHEC28 11.7(2.6)l/min(gpm) at35 degree rise.
ThenominalDHWtemperatureis55 °C,butwaterdrawnoff
whentheboilerhasbeenonforcentralheatingmaybehotter
thanthis,forashortperiodoftime.
GAS SAFETY
CurrentGasSafety(InstallationandUse)
Regulationsor rulesinforce
Theapplianceis suitableonlyforinstallationinGBandIEand
should beinstalledinaccordancewiththerulesinforce.
InGB,theinstallationmustbecarriedoutbyaCORGI
RegisteredInstaller.Itmustbecarriedoutinaccordancewith
therelevantrequirementsofthe:
FGasSafety(InstallationandUse)Regulations
FTheappropriateBuildingRegulationseitherTheBuilding
Regulations,TheBuildingRegulations(Scotland),
BuildingRegulations(NorthernIreland).
FTheWaterFittingsRegulationsorWaterbyelawsin
Scotland.
FTheCurrentI.E.E.WiringRegulations.
Wherenospecificinstructionsaregiven,referenceshould be
madetotherelevantBritishStandardCodeofPractice.
InIE,theinstallationmustbecarriedoutbyaCompetent
Personandinstalledinaccordancewiththecurrenteditionof
I.S.813 ”DomesticGasInstallations”,thecurrentBuilding
Regulationsandreferenceshould bemadetothecurrent
ETCIrulesforelectricalinstallation.
Detailedrecommendationsarecontainedinthefollowing
BritishStandardCodesofPractice:
BS5440:1Flues(forgasappliancesofratedinputnot
exceeding70 kW).
BS5440:2Ventilation(forgasappliancesofratedinput
notexceeding70 kW).
BS.5449 Forcedcirculation hotwatersystems.
BS.5546 Installationofgashotwatersuppliesfor
domesticpurposes(2ndFamilyGases)
BS6700 Design,installationtestingandmaintenanceof
services supplyinghotwaterfordomesticuse.
BS.6798 Installationofgasfiredhotwaterboilersof
ratedinputnotexceeding70 kW.
BS.6891 Lowpressureinstallationpipes.
Health&SafetyDocumentNo.635.
TheElectricityatWorkRegulations,1989.
ThemanufacturersnotesmustNOTbetaken,inanyway,as
overridingstatutoryobligations.
IMPORTANTTheseappliancesareCEcertificatedforsafety
and performance.Itis,therefore,important thatnoexternal
controldevices,e.g.fluedampers,economisersetc., are
directlyconnectedtotheseappliancesunless covered by

GENERAL
miniHE --- Installation&Servicing
8
theseInstallationandServicingInstructionsorasotherwise
recommended byCaradonIdealLtd.inwriting.Ifindoubt
please enquire.
Anydirectconnectionofacontroldevicenotapproved by
CaradonIdealLtd.couldinvalidatethecertificationandthe
normalappliancewarranty.ItcouldalsoinfringetheGas
SafetyRegulationsandtheaboveregulations.
SAFE HANDLINGOFSUBSTANCES
Careshould betakenwhen handlingtheboilerinsulation
panels,whichcancauseirritationtotheskin.Noasbestos,
mercuryorCFCsareincludedinanypartoftheboilerinits
manufacture.
LOCATIONOFBOILERANDFLUEOUTLET
Theboilermustbeinstalledonaflatandverticalwall,capable
ofadequatelysupportingtheweightoftheboilerandany
ancillaryequipment.
Theboilermaybefittedonacombustiblewall andinsulation
betweenthewall andtheboilerisnotnecessary,unless
required bythelocalauthority.
Theboilermustnotbefittedoutside.
TimberFramedBuildings
Iftheboileristobefittedinatimberframed buildingitshould
befittedinaccordancewiththeInstituteof GasEngineers
documentIGE/UP/7,1998.
BathroomInstallations
Theboilermaybeinstalledinanyroomorinternalspace,
althoughparticularattentionisdrawntotherequirementsof
thecurrentI.E.E.(BS.7671)WiringRegulationsand,in
Scotland,the electricalprovisionsofthebuildingregulations
applicableinScotlandwithrespect totheinstallationofthe
boilerinaroomorinternalspacecontainingabathorshower.
ForIrelandreferenceshould bemadetothecurrentETCI
rulesforelectricalinstallationsandI.S.813:2002
Wherearoomsealedapplianceisinstalledinaroom
containingabathorshowerthentheapplianceandany
electricalswitchorappliancecontrolutilisingmainselectricity
should besosituatedthatitcannotbetouched byaperson
usingthebathorshower.
Note.Itisnotpermissibletoinstall amains socketina
bathroom.
Whereinstallationwill beinan unusual location,special
proceduresmaybenecessaryandBS6798 givesdetailed
guidanceonthisaspect.
CompartmentInstallations
Acompartmentusedtoenclosetheboilershould be
designedandconstructedspeciallyforthispurpose.
Anexistingcupboardorcompartmentmaybeused,provided
thatitismodifiedforthepurpose.
Inbothcasesdetailsofessentialfeaturesofcupboard/
compartmentdesign,includingaircupboardinstallation,are
toconformtothefollowing:
FBS6798 (Nocupboardventilationisrequired--- see “Air
supply”fordetails)
FThepositionselectedforinstallationMUSTallow
adequatespaceforservicinginfrontoftheboiler.
FFortheminimumclearancesrequiredforsafetyand
subsequentservice,see thewall mountingtemplateand
frame2.Inaddition,sufficientspacemayberequiredto
allowliftingaccess tothewall mountingplate.
GAS SUPPLY
Thelocalgas suppliershould beconsulted,at theinstallation
stage,inordertoestablishtheavailabilityofanadequate
supplyofgas.AnexistingservicepipemustNOTbeused
withoutpriorconsultationwiththelocalgas supplier.
Naturalgasboilersmustbeinstalledonagas supplywitha
governedmeter.Agasmetercanonlybeconnected bythe
localgas supplierorbyaregisteredCORGIengineer.
PropanegasboilersMUSTbeinstalledwithpipes,cylinders
and pressureregulatorsfittedinaccordancewithBS.5482.1.
BulktankinstallationsMUSTcomplywiththeHomeOffice
codeofpracticeforstorageofliquefied petroleumgasatfixed
installations.ThecompleteinstallationMUSTbetestedfor
gas soundness and purgedasdescribedintheabovecode.
Theboilerisadjustedat thefactoryforusewiththerelevant
supplygas.Aworking gaspressure equaltothatstatedin
Table1MUSTbeavailableat theboilerinlet.
Whereapplicable,theappliancecanbeconvertedfor
G20---NaturalGasorG31---PropaneGasbyusingthe
appropriateconversionkit.
IMPORTANTInstallationpipesMUSTbefittedinaccordance
withBS.6891.InIErefertoI.S.813.2002.
PipeworkfromthemetertotheboilerMUSTbeofan
adequatesize,i.e.notless than22 mm O.D.copperor3/4”
BSPiron.
FLUEINSTALLATIONREQUIREMENTS
Thefluemustbeinstalledinaccordancewiththe
recommendationsofBS.5440--- 1 2000.
InIErefertoI.S.813.2002.
Thefollowingnotesareintendedforgeneralguidance.
1TheboilerMUSTbeinstalledsothat theterminalis
exposedtoexternalair.
2Itisimportant that thepositionoftheterminalallowsthe
free passageofairacross itatall times.
3Minimumacceptablespacingfromtheterminalto
obstructionsandventilationopeningsarespecifiedin
Table4.
4Wherethelowestpartoftheterminalisfittedless than2m
(6’6”)aboveabalcony,abovegroundoraboveaflatroof
towhichpeoplehaveaccess thentheterminalMUSTbe
protected byapurposedesignedguard.
Ensurethat theguardisfittedcentrally.
5Wheretheterminalisfittedwithin850mm (34”)ofaplastic
orpaintedgutteror450mm (18”)ofpaintedeavesthenan
aluminiumshieldatleast750mm (30”)longshould be
fittedtotheundersideofthegutterorpaintedsurface
fittedcentrallyabovetheflue.
6Theairinlet/productsoutletductandtheterminalofthe
boilerMUSTNOTbecloserthan25mm (1”)to
combustiblematerial.Detailedrecommendationsonthe
protectionofcombustiblematerialaregiveninBS.
5440--- 1:2000.InIErefertoI.S.813.2002.
Table4--- Balancedflueterminalposition
TerminalpositionMinimumspacing
1Directlybelow,aboveoralongside
ofanopenablewindow,airventor
otherventilationopening
300 mm (12”)
2Belowguttering,drainpipesorsoil
pipes
25 mm (1”)
3Beloweaves25 mm (1”)
4Belowbalconiesoracarportroof25 mm (1”)
5Fromverticaldrainpipesorsoil
pipes*
25 mm (1”)
6Fromaninternalorexternalcorner
ortoaboundaryalongsidethe
terminal
25 mm (1”)

GENERAL
miniHE --- Installation&Servicing9
7Aboveadjacentground,roofor
balconylevel
300 mm (12”)
8Fromasurfaceoraboundary
facingtheterminal.
600 mm (24”)
9Fromaterminalfacingaterminal1200 mm (48”)
10 Fromanopeninginacarport(e.g.
doororwindow)intodwelling
1200 mm (48”)
11 Verticallyfromaterminalonthe
samewall
1500 mm (60”)
12 Horizontallyfromaterminalonthe
wall
300 mm (12”)
*Iftheterminaliswithin150mm ofanyverticalsoilordrain
pipe,analuminiumshieldatleast400mm (15 3/4”)long
should befittedequi--- distantfromtheterminalandcloseto
thepipe.
VerticalTerminals
13 Abovetheroofpitchwithroof
slopeofall angles.
Aboveflatroof
300 mm (12”)
300 mm (12”)
14 Fromsinglewall face
Fromcornerwall faces
600 mm (24”)
1000 mm (40”)
TwinFlueApplications
15 Centredistancebetweenairinlet
andflueoutletducts
120mm (5”)**
** Wherethetwinflueductsarepositionedatorneartheabove
minimumcentresthewall sealing gaskets should betrimmedto
allowthemtofitflat tothewall.This should bedoneforbothin-
sideandoutsidewall gaskets
Terminalsguardsareavailablefromboilersuppliers--- askfor
TowerFlueGuard,ModelK6.Incaseofdifficultyseekadvice
from:
GrasslinUKLtd.,Towerhouse,ValeRise,Tonbridge,
KentTN9 1TBTel.+44 (0)1732 359 888 FaxNo.+44 (0)
1732 354 455 www.tfc--- group.co.uk
IMPORTANTItisabsolutelyESSENTIALtoensure,in
practice,thatproductsofcombustiondischargingfromthe
terminalcannotre--- enterthebuildingoranyotheradjacent
buildingthroughventilators,windows,doorsothersourcesof
naturalairinfiltration,orforcedventilation/airconditioning.
Ifthis shouldoccurtheapplianceMUSTbeturnedOFF,
labelledas“unsafe”untilcorrectiveactiontaken.
AIRSUPPLY
ItisNOTnecessarytohaveapurpose--- providedairventin
theroomorinternalspaceinwhichtheboilerisinstalled.
Neitherisitnecessarytoventilateacupboardor
compartmentinwhichtheboilerisinstalled,duetothelow
surfacetemperaturesoftheboilercasingduringoperation;
thereforetherequirementsofBS6798,Clause12,BS5440:2
andinIEI.S.813:2002 maybedisregarded.
WATER CIRCULATIONSYSTEM
Theboilersaredesignedforconnectiontopressurised,fully
pumped,sealedwatercentralheatingsystemsONLY.The
domestichotwater(DHW)calorifierisincorporatedwithinthe
combiboilerandonlyrequiresconnectiontothemainswater
supply.
AdditionalPumps.
Theboileris suppliedwithanintegralcirculatingpump.Ifthe
boileristobeusedinconjunctionwithanyadditional
circulatingpumps,pleasecontact theTechnicalHelplinefor
adviceonapplication.
IMPORTANT
Aminimumlengthof1mofcopperpipeMUSTbefittedto
bothflowandreturnconnectionsfromtheboilerbefore
connectiontoanyplasticpiping.
Ensurethat themainswatersupplypressureisadequateto
providetherequiredDHWflowrate.RefertoTable1on
page4.
Thecentralheatingsystemshould beinaccordancewithBS.
6798 and,inaddition,forsmallboreandmicroboresystems
BS.5449.
Thedomestichotwatersystemshould beinaccordancewith
BS.5546 andBS.6700.
CoppertubingtoBS2871:1isrecommendedforwater
carryingpipeworkandMUSTbeusedforpipeworkcarrying
potablewater.
AnysolderedjointsonpotablewaterpipeworkMUSTNOTbe
madewithsoldercontaininglead.
Ancillarypipeworknotformingpartoftheusefulheating
surfaceshould belaggedtopreventheatloss andany
possiblefreezing--- particularlywherepipesrun throughroof
spacesorventilatedunderfloorspaces.
Drainingtaps should beatleast1/2”BSPnominalsizeand
beinaccordancewithBS2879.
WATER TREATMENT
CentralHeating
Antifreezefluid,corrosionandscaleinhibitorfluids suitablefor
usewithboilershavingcopperheatexchangersmaybeused
inthecentralheatingsystem.
IMPORTANT
Theapplicationofanyothertreatment tothisproduct
mayrendertheguarantee ofCaradonIdealLimited
INVALID.
CaradonIdealLimitedrecommendWaterTreatmentin
accordancewiththeBenchmarkGuidanceNotesonWater
TreatmentinCentralHeatingSystems.
CaradonIdealLimitedrecommendtheuseofFernox,GE
BetzSentinelorSalamanderwatertreatmentproducts,which
mustbeusedinaccordancewiththemanufacturers
instructions.
Notes.
1.Itismostimportant that thecorrectconcentrationofthe
watertreatmentproductsismaintainedinaccordancewith
themanufacturers’instructions.
2.Iftheboilerisinstalledinanexistingsystemanyunsuitable
additivesMUSTberemoved bythoroughcleansing.
BS7593:1992 detailsthestepsnecessarytocleana
domesticheatingsystem.
3.Inhardwaterareas,treatment topreventlimescalemaybe
necessary--- however,theuseofartificiallysoftenedwateris
NOTpermitted.
4.Undernocircumstances shouldtheboilerbefired before
thesystemhasbeenthoroughlyflushed.

GENERAL
miniHE --- Installation&Servicing
10
DomesticHotWater
In hardwaterareaswheremainswatercanexceed200ppm
TotalHardness (asdefined byBS7593:1993 Table2)ascale
reducingdeviceshould befittedintotheboilercoldsupply
withintherequirementsofthelocalwatercompany.Theuse
ofartificiallysoftenedwater,however,isNOTpermitted.
CaradonIdealLimitedrecommendtheuseofFernox
Qantomat,GEBetzSentinelCombiguardandCalmag
CalPhosIscalereducingdevices,whichmustbeusedin
accordancewiththemanufacturers’instructions.
Forfurtherinformationcontact:
Fernox
CooksonElectronics
ForsythRoad
Sheerwater
Woking
Surrey
GU21 5RZ
[phone]
CalmagLtd.
Unit4---6CrownWorks
BradfordRoad
Sandbeds
Keighley
WestYorkshire
BD20 5LN
[phone]
Salamander(Eng)Ltd
ReddicapTradingEstate
SuttonColdfield
WestMidlands
B75 7BY
[phone]
GEBetz
SentinelDivision
FoundryLane
Widnes
Cheshire
WA8 8UD
[phone]
3ELECTRICALSUPPLY
Warning.Thisappliancemustbe efficientlyearthed.
WiringexternaltotheapplianceMUSTbeinaccordancewith
thecurrentI.E.E.(BS.7671)WiringRegulationsandanylocal
regulationswhichapply.ForIrelandreferenceshould be
madetothecurrentETCIrulesforelectricalinstallations.
Thepointofconnectiontothemains should bereadily
accessibleandadjacent totheboiler,exceptforbathroom
installationswherethepointofconnectiontothemainsMUST
besituatedoutsideofthebathroom.
Note.Wherearoomsealedapplianceisinstalledinaroom
containingabathorshowerthentheapplianceandany
electricalswitchorappliancecontrolutilisingmains
electricityshould besosituatedthatitcannotbetouched by
aperson usingthebathorshower.
4 SEALED SYSTEMREQUIREMENTS
CentralHeating
Note.miniHEboilersaresuitableforfullypumped
pressurisedsealedsystemsonly.
REQUIREMENTS
1General
Theinstallationmustcomplywiththerequirementsof
BS.6798 andBS.5449.
2FlowTemperature
Theinstallationshould bedesignedtoworkwithflow
temperaturesofupto90 °C.
3WorkingPressure
All componentsofthesystem mustbesuitableforaworking
pressureof3bar(45 lb/in2)andtemperatureof110 °C.Extra
careshould betakeninmakingall connections sothat the
riskofleakageisminimised.
Thefollowingcomponentsareincorporatedwithinthe
appliance:
a.Circulatingpump.
b.Safetyvalve;withanon---adjustablepre---setliftpressureof
3bar(45lb/in2).
c.Pressuregauge;coveringarangeof0---4bar.
d.6litre expansionvessel;withaninitialchargepressureof
0.7bar(10.5lb/in2).
ForfurtherdetailsrefertoBS.5449:1andtheBritishGas
Corporationpublication’SpecificationsforDomesticCentral
HeatingandHotWater’.
4Fillingthesystem
Fill thesystemthroughatemporaryhoseconnectionfroma
draw---off tapsuppliedfromaservicepipeundermains
pressure.Wherethemainspressureisexcessiveapressure
reducingvalveshall beusedtofacilitatefilling.
Wheninstallingthefillingconnectionprovidedwiththeboiler
anadditionalWRASapprovedvalvemustbefittedtothe
mainswatersupplyupstreamofthedoublecheckvalveto
fullycomplytheWaterRegulations
CHreturn
HoseunionsMains
Water
Supply
Temporaryhose
(disconnect
afterfilling)
StopvalveAdditionalstopvalve
Doublecheckvalve
assembly
Notedirectionof flow
Systemfillingandmake---up
Proceedwiththefollowing:
FThoroughlyflushout thewholeofthesystemwithcold
waterbeforefittingtheboiler.
FFill andvent thesystemuntilthepressuregaugeregisters
1.5bar(22 lb/in2).Examineforleaks.
FReleasewaterfromthesystemuntilapressureof1bar
(15 lb/in2)isreached.
Toavoidgettingdebrisonthevalveseat,donotuse
thesafetyvalvetodothis.
FLight theboilerandheat thesystemtothemaximum
workingtemperature.Examineforleaks.
FTurnoff theboilerand drainthesystemwhilestill hot.
FRefill andvent thesystem.
FRe---pressurisethesystemtothedesiredchargepressure
(see Table5).

GENERAL
miniHE --- Installation&Servicing11
Table5
Systemchargepressure
(bar)
0.5 0.7 1.0
Safetyvalvesetting3.0
Vesselpre---chargepressure
(bar)
0.7
Systemvolume(litres)Volumeofexpansionvessel
inadditionto6litreunit
fittedtoboiler
75 --- --- ---
100 0.3 0.8 1.4
125 1.8 2.5 3.2
150 3.4 4.2 5.0
175 5.0 6.0 7.0
200 6.5 7.6 8.7
225 8.1 9.3 10.6
250 9.6 11.1 12.4
275 11.2 12.8 14.3
300 12.8 14.5 16.1
Multiplythisfactorby
systemvolumeand deduct
6litresto obtainsizeof
additionalvesselforother
systemvolumes.
0.063 0.069 0.074
5Sizeofexpansionvessel
Forthesystemwaterexpansiontobecontained bythe6litre
expansionvesselthecoldsystemvolumemustnotexceed:
96 litreswhenpressurisedto0.5bar(cold)
88 litreswhenpressurisedto0.7bar(cold)
81 litreswhenpressurisedto1.0bar(cold)
Ifthepressure exceeds2.65 barwhentheboilerisupto
temperaturewithall radiatorsin usethenanadditional
expansionvesselMUSTbeinstalledonthereturnpipework.
Forexpansionvolumes see Table5.
GuidanceonvesselsizingisgiveninBS7074:1andBS5449
ForIErefertothecurrenteditionofI.S.813.
6HydraulicLoss
Remainingpumpcapacity
0
1
2
3
4
5
6
0 200 400 600 800 1000 1200 1400
Flowratel/hour
m
H
2
O
7Drainingthesystem
DrainingtapsMUSTbelocatedinaccessiblepositionsto
permit thedrainingofthewholecentralheatingsystem,
includingthecentralheatingsideoftheboiler.Thetaps
should beatleast1/2”BSPnominalsizeand bein
accordancewithBS2879.

GENERAL
miniHE --- Installation&Servicing
12
5BOILER CONTROLINTERLOCKS
Thermostaticradiatorvalves.
CaradonIdealLtd.support therecommendationsmadeby
leadingmanufacturersofdomesticheatingcontrolsthat
heatingsystemsutilisingfull thermostaticradiatorvalve
controloftemperatureinindividualrooms shouldalsobe
fittedwitharoomthermostatcontrollingthetemperatureina
spaceserved byradiatorsnotfittedwithsuchavalveas
statedinBS5449.Suchanarrangementwill providefora
more efficientcontrolofthe environmentandwill alsoavoid
thecontinuousrunningofthecirculationpump during
programmedheatingONperiods,savingelectricalenergy.
Itisthereforestronglyrecommendedthat,whenthermostatic
radiatorvalvesareused,thespaceheatingtemperature
controloveraliving/diningareaorahallway,havingaheat
requirementofatleast10%oftheboileroutput,isachieved
usingaroomthermostatwhilstother roomsareindividually
controlled bythermostaticradiatorvalvesas statedin
BS5449.
Forfurtherinformationreferto“GoodPractiseGuide143”a
publicationofthe energyefficiencyoffice,availablefromthe
buildingresearchestablishmentGarstonWatfordWD2 7JR
tel:[phone]
Theboilerisfittedwithanautomaticinternalbypass.No
furthersystembypass isrequired.
Typicalinstallation
DA
TRV
B
Room
T/stat
Balancingvalve
TRV
TRV
6 DOMESTICHOT WATER
REQUIREMENTS
1Thedomestichotwaterservicemustbeinaccordance
withBS5546 andBS6700.
2Fortheminimumandmaximumworkingpressuresofthe
miniHEC24 andminiHEC28 domestichotwatercircuit
refertoTable1,page4.
3Thecoldwatersupplypipeshould beflushed before
fittingtheboiler.
4Theboilersaresuitableforconnectiontomost typesof
washingmachineand dishwashingappliances.
5Whenconnectingtosuitableshowers,i.e.thosedesigned
formodulatingdomestichotwater,ensurethat:
a.Thecoldinlet totheboilerisfittedwithanapproved
anti---vacuumorsyphon non---returnvalve.
b.Hotandcoldsuppliesareofequalpressure.
6Hardwaterareas
Inareaswherethewateris’hard’itisrecommendedthat
aproprietaryscale--- reducingdeviceisfittedintotheboiler
coldsupply,withintherequirementsofthelocalwater
company.

GENERAL
miniHE --- Installation&Servicing13
7BOILER WATER CIRCUITDIAGRAM
32
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
23
24
25
22
26
27
28
29
30
31
33
1
2
34
34 35
36
37
1Domestichotwater(DHW)heatexchanger
2Domestichotwater(DHW)flowswitch
3Domestichotwater(DHW)outletpipe
4Domestic coldwaterinletcock
5Three--- waydivertervalve
6Maincircuitdrainagecock
7Centralheatingflowcock
8By---pass valve
9Centralheating(CH)returncock
10 3 barpressurereliefvalve
11 Gascock
12 Expansionvessel
13 Gasvalveinletpressuretap
14 Modulating gasvalve
15 Burnerpressuretap
16 Flamedetectionelectrode
17 Ignitionelectrodes
18 Burner
19 Combustionchamber
20 Primaryheatexchanger
21 Fan
22 Airpressureswitch
23 Venturidevice
24 Flueoutletpipe
25 Airintakepipe
26 Automaticairvent
27 Overheat thermostat
28 Pump
29 Pumpventplug
30 Watercircuit temperatureprobe
31 CHflowswitch
32 DHWtemperatureprobe
33 CHcircuit temperature/pressuregauge
34 Recuperator
35 Fluethermostat
36 Condensatetrap
37 Condensatedrainpipe

INSTALLATION
14 miniHE --- Installation&Servicing
8BOILERASSEMBLY---
Exploded View
17
38
1
11
27
7
10
18
8
40
23 21
4
24
16
14
13
32
28
26
12
29
30
31
15
33
34
36
35
9
6
37
20
39
1922
2
41
3
5
25
1Airpressureswitch
2Recuperator
3Condensatetrap
4Overheat thermostat
5Condensingtomain heat
exchangerconnectionpipe
6Primaryheatexchanger
7Innercasecover
8Flamedetectionelectrode
9Ignitionelectrodes
10 Heatexchanger returnpipe
11 Autoairvent
12 Maincircuitdrainagecock
13 Pump
14 DHWflowswitch
15 DHWThermistor
16 Ignitionpcb
17 Righthand panel
18 Boilerfrontpanel
19 Appliancedatabadge(inside)
20 Lefthand panel
21 CHcircuitpressuregauge
22 Modelidentification&instructions
23 Controlpaneldoor
24 Maincontrolpcb
25 CHThermistor
26 CHflowswitch
27 Heatexchangerflowpipe
28 Returnmanifold
29 3 waydivertervalve
30 DHWheatexchanger
31 Bypass pipe
32 3 barpressurereliefvalve
33 Gasvalve
34 Gasvalveoutletpipe
35 Injectormanifold
36 Burner
37 Fluehood
38 Fan
39 Expansionvessel
40 Venturi
41 Fluethermostst
INSTALLATION

INSTALLATION
miniHE --- Installation&Servicing15
9 UNPACKING
Theboileris suppliedfullyassembledinonepackA,together
withastandardflueassemblyforlengthsupto960 mm
(37”3/4),rearorsideflueoutlet,inpackB.
Unpackandcheckthecontents.
PackAcontents
ATheboiler.
BHardwarepack
CWall mountingplate
DWall mountingtemplate
EUser’s,Installation&Servicinginstructions.
F Fillingloopassembly
A
B
C
D
E
F
Hardwarepackcontents
F22 mm CHconnectionpipe--- 2off.
F22 mm Gas supplyconnectionpipe--- 1off.
F15 mm DHWcoldinletconnectionpipe--- 1off.
F15 mm DHWhotoutletconnectionpipe--- 1off.
F1/2”connection nut--- 2off.
F1/2”sealingwasher--- 3off.
F3/4”sealingwasher--- 6off.
F3/4”Gas supplyisolatingvalve--- 1off.
F3/4”CHcircuitisolatingvalve--- 2off.
F1/2”DHWcoldinletisolatingvalve--- 1off.
PackBcontents
GAirintakepipeø100 mm (4”),fluepipeø60 mm (2”3/8)
withterminalgrilleassembly
HCentringspring
ITurret---airpipegasket
JFluepipegasket
KBoiler---turretgasket
LFlueturret
MSelftappingscrews4,8x13 --- 4off
NWall finishing gasket--- internal(plastic)
OWall finishing gasket--- external(rubber)
G
H
I
J
K
L
M
NO
Optionalextras,ifordered,areavailableinseparateboxes.
FElectronicprogrammerkits--- 24 hrs&7day
FExtensionductkitpackD(ø60/100)
FFluesupportkitsø80,100,125
FVerticaloutletfluekitwithelbow(ø60/100)
F90°Elbowkit(ø60/100)
F45°Elbowkit(ø60/100)
FRoof fluekit(ø80/125)
FUniversalweathercollar(for roof fluekit)
FFlatroofweathercollar(for roof fluekit)
FExtensionductkit(ø80/125)
F90°Elbowkit(ø80/125)
F45°Elbowkit(ø80/125)
FCondensedrainvertical(ø80/125)
FTwinpipekit(ø80)withairandflueterminals
FExtensionductkit(ø80)
F90°Elbowkit(ø80)male--- female
F45°Elbowkit(ø80)male--- female
FVerticalcondensedrain(ø80)
FHorizontalcondensedrain(ø80)
FCondensetrap
FStand---off bracket
FNaturalgastoLPGconversionkit
FLPGtonaturalgasconversionkit
FCondensatepumpkit
10 PACKAGING
Tounpacktheboiler refertotheinstructionsoncartonend
flap.
INSTALLATION

INSTALLATION
miniHE --- Installation&Servicing
16
11 FITTINGTHE FLUESYSTEM
Theminimumandmaximumequivalentlengthfor
co---axialpipesø60 ---100 andø80---125 mm aregivenin
Table6.
Theminimumandmaximumequivalentlengthforø80
mm twinpipesystemsaregiveninTable7.
For roof fluesystemshavingafluelengthgreaterthan
3mandall twinpipesystems,acondensatedrainkit
mustbefittedat thelowestpointinthesystem.See the
listofoptionalextras(frame9)foravailabledrainkits.
Refertotheassemblyinstructionscontainedwithinthe
chosenfluekitpackagingforthecorrectassemblyand
installation.
Thehorizontalsectionsof fluepipesmusthaveaslope
notless than1.5deg.(25 mm permetre)towardsthe
boiler.
InthefluekitofpackBthefluepipeisangledwithintheair
duct thereforetheairductmustbehorizontallyinstalled.
Inthecasethatoneormore extensionsneedtobeusedthey
mustbeadequatelysupportedsothat thereisnosaginthe
fluepipeandaminimumfall of1.5deg.(25 mm permetre)
overthewholelengthtowardstheboilerisensured.
Table6
MinimumMaximum
Co---axial60--- 100 0.3(11.8”)2.7(8’10”)
Co---axial80--- 125 0.5(19.7”)8.5(27’10”)
Co---axialFluekits.
Horizontal.
Forcalculationoftotalfluelength,thedistanceMUSTbe
measuredfromthecentrelineoftheconcentricelbowtothe
endoftheterminal.
Verticaloutlet
Forcalculationoftotalfluelength,thedistanceMUSTbe
measuredfromthecentrelineoftheoutletconnectorat the
boilertop paneltothe endoftheterminalgrille.
Foreachadditional45°and90°fluebendused,the
maximumpermissiblelengthof fluesystem mustbereduced
by1mor1,5mrespectively.
Cuttinglengthsof flueandairducts
Measurethewall thickness and,when usingasideoutlet,the
gap betweentheinnerwall andtheboilersidecasing.
Usethefollowingchart tocalculatethecuttinglengthofair
duct.
Marktheairductmakingreferenceonthegroove.
Cut theflueductat thesameleveloftheairductedge.
Groove
Cut thisend
HorizontalConcentric
Airduct
RearOutletWall thickness +125 mm
Rearoutlet+Stand--- off Wall thickness +160 mm
SideOutlet--- RHWall thickness +Gap+62 mm
SideOutlet--- LHWall thickness +Gap+208 mm
Twinpipefluekits
Forcalculationoftotalfluelength,thedistanceMUSTbe
measuredfromthecentrelineoftheflueduct/airduct
connectiontothe endoftheflueoutletgrille/airinletduct.
Foreachadditional45°M&Fand90°M&Ffluebendused,
themaximumpermissiblelengthof fluesystem mustbe
reduced by0,9mor1,65mrespectively.
Tworestrictorswithdifferentsizesaresuppliedwiththetwin
pipekitandhavetobeinstalled betweentheboilerandthe
airintakeadapterasindicatedinthefollowingpicture.
Therestrictortobeusedandthelengthsofallowable
equivalentflueoutlet/airinletductsareindicatedinTable7
andinthefollowing graph.
Therestrictorsizeismarkedonitsbody.
Airintakeadapter
Restrictor
Gasket
Table7
Equivalentpipelength
(airduct+flueduct)
Restrictor
Between1(39“)and15 m(49’2”)ø50 mm
Morethan15 m(49’2”)upto30 m(98’5”)ø55 mm
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32
Restrictor
50 mm
Allowedvalues
Flue exhaust”a”
Airintake”b”
Restrictor
55 mm
INSTALLATION

INSTALLATION
miniHE --- Installation&Servicing17
Cuttinglengthsof flueandairducts
Measurethewall thickness and,when usingasideoutlet,the
gap betweentheinnerwall andtheboilersidecasing.Use
thefollowingchart tocalculatethecuttinglengthsofbothflue
andairducts.
Marktheairductandflueductmakingreferenceonthe
groove.
GrooveGroove
TwinPipe
Airduct
RearOutletWall thickness +130 mm
Rearoutlet+Stand--- off Wall thickness +165 mm
SideOutlet--- RHWall thickness +Gap+187 mm
SideOutlet--- LHWall thickness +Gap+93 mm
FlueDuct
RearOutletWall thickness +130 mm
Rearoutlet+Stand--- off Wall thickness +165 mm
SideOutlet--- RHWall thickness +Gap+67 mm
SideOutlet--- LHWall thickness +Gap+213 mm
12 REARFLUEASSEMBLY
Legend
1Wall finishing gasket--- external(rubber)
2Selftappingscrew4,2x13
3Flueturret
4Boiler---turretgasket
5Fluepipegasket
6Turret---airpipegasket
7Centringspring
8Air/fluepipewithterminalgrilleassembly
9Wall finishing gasket--- internal(plastic)
1
8
9
7
65
4
3
2
13 WALL MOUNTINGTEMPLATE
(rear flue)
IMPORTANT
Detailedinstallationstepsaregivendirectlyonthewall
mountingtemplate
1Tapethetemplateintotheselected position.
2Ensuresquareness byhangingaplumbine.
3Markontothewall thefollowing:
a.thewall mountingplatescrewpositions
b.thepositionoftheflueduct.
(Markthecentreoftheholeaswell asthecircumference)
4Removethetemplatefromthewall
a
b
INSTALLATION

INSTALLATION
miniHE --- Installation&Servicing
18
14 WALL MOUNTINGTEMPLATE
(sideflue)
IMPORTANT
Detailedinstallationstepsaregivendirectlyonthewall
mountingtemplate
1Tapethetemplateintotheselected position.
2Ensuresquareness byhangingaplumbine.
3Markontothewall thefollowing:
a.thewall mountingplatescrewposition
b.Extendedthecentrelineas shown.
Marktheflueductcentrefromthecorner(see diagram
andtemplate)
Note.markthecentreoftheholeaswell asthe
circumference.
IfextensionductkitpackDhastobeused,thepipesmust
havethecorrectslopeasdetailedinframe11.
4Removethetemplatefromthewall
Extendedcentre
Spiritlevel
15 DRILLINGTHE WALL
Rear flueshown
IMPORTANT
Ensurethat,duringthecuttingoperation,masonryfalling
outsidethebuildingdoesnotcausedamageorpersonal
injury.
1Cut thefluehole(preferablywitha5”coreboringtool),
ensuringthat theholeis squaretothewall.
2Drill thefixingholeswithan8mm (5/16”)masonrydrill.
Fitsuitablewall plugs(notprovided).
Note.Iftheteminal istobesitedwithin25 ---40 mm ofa
cornerorverticalpipe(refertoTable4)thentheholeMUST
beaccuratelycutandtherubberweathersealtrimmed.
5”diameter
fluehole
Section
throughwall
Note:Checkall ofthehole
positionsbeforedrilling.
16 FITTINGTHE WALL
MOUNTING PLATE
Refertoframe18 forserviceconnections.
Fit thewall mountingplate
Directlytothewall
FOfferupwall mountingplate.
FScrewthroughthefixingholesusing3off no.14x2”
screws(notprovided).
FCheckalignmentwithspiritlevel.
FTightenscrews.
INSTALLATION

INSTALLATION
miniHE --- Installation&Servicing19
17 MOUNTINGTHE BOILER
Lift theboilerontothewall mountingplatelocatingthebarat
therearofthebackpanelassemblyintothebracket.
Asadded protection,theboilershould beliftedwiththelower
polystyrenepackaginginplace.
Lowertheboilerintoposition.
Removethelowerpackaging.Removethefrontandside
panels(refertoframe22)andstripoff theprotectivecoating.
Thepanelsmaybeplacedto onesideandre---fittedwhenthe
installationiscomplete.
Note.Beforefittingthefluesystem,filithecondensatetrap
withintheboilerbypouringacupfulofwaterintotheflue
outietA.Takecaretoensurethat thewaterisonlypouredinto
theflueoutiet,and doesnotspill intotheboilercasing.
Fit thefluesystemreferringtotheinstructionscontainedwith
thekit.
Makegoodtheinternalwall surfaceusingthesealprovided.
A
18 CONNECTIONS
Fit theservicevalveswashersandtailpipesas shown.
CentralHeatingflow
Domestichot
wateroutletGasinlet
Domestic cold
waterinletCentralHeatingreturn
Connect tothetailpipesbyproprietoryfittings.
Thepipeworkmaybedirected downorthroughtherearwall
asrequired.
Thepipeworkmaybedirectedupwardsbyusingtheoptional
standoff bracketkit.See illustrationforupward pipework
routing
19 SAFETYVALVEDRAIN
Thedischargepipeshould bepositionedsothat the
dischargeofwaterorsteamcannotcreateahazardtothe
occupantsofthepremisesordamagetoelectrical
componentsandwiring.
Pressure
Dischargepipe
reliefvalve
INSTALLATION

INSTALLATION
miniHE --- Installation&Servicing
20
20 CONDENSATEDRAIN
ReferalsototheBritishGasdocument:“GuidanceNotes
fortheinstallationofDomesticGasCondensingBoilers”
(1989).
Thecondensatedrainprovidedontheboilermustbe
connectedtoadrainagepoint,preferablywithinthebuilding.
Theboilerincludesatrapthatpreventscombustionproducts
enteringthedrain.Howeveranadditionaltrapwithasealofat
least75 mm andanairbreakbetweenthetrapsisrequiredif
thecondensatedrainpipeisconnectedtosanitarypipework.
Condensatedrain
Additionaltrap
Thelengthofthecondensatepipeshould bekeptat
minimumandmustbearrangedsothatobstruction(e.g.
throughfreezing)ofexternaldrainagepipeworkdoesnotgive
risetospillagewithinthedwelling.
Ifapartofthedrainpiperunsexternallythispartshould be
keptas shortaspossibleand protectedtoreducetheriskof
freezing.
IMPORTANT
Ifexcessive externalpipeworkcannotbeavoidedan
additionalcondensateremovalpump(availableasan
option)andinsulationarerecommendedtopreventpossible
freezing.
Thedrainoutletontheboilerisa25 mm o.d.plasticpipe.
This sizemustnotbereduced below21.5mm o.d.(standard
overflowpipe)inanypartofitslength.
All pipeworkandfittingsinthecondensatedrainsystem must
bemadeofplastic.No othermaterialsmaybeused.
Toavoidcondensatebeingtrapped:
--- thedrainpipeshould berun withafall ofatleast2.5°(45
mm/m)awayfromtheboiler;
--- thenumberofbendsandjoints should bekeptat
minimum;
--- thedrainpipeshould beadequatelyfixedtopeventpipe
sagging.
21 ELECTRICALCONNECTIONS
Warning.ThisapplianceMUSTbe efficientlyearthed
Amains supplyof230 V~50 Hzisrequired.
Mainswiringshould be3corePVCinsulatedflexiblecord
NOTLESS than0.75 mm2(24 x0.2mm)andtoBS.6500,
Table16.(0.5mm2flexisnotacceptable--- formechanical,
notelectricalreasons.)
MainswiringexternaltotheboilerMUSTbeinaccordance
withthecurrentI.E.E.(BS7671)WiringRegulationsandany
localregulations.
ForIrelandreferenceshould bemadetothecurrentETCI
rulesforelectricalinstallations.
Thesupplyconnectionisintendedtobemadeviaadouble
poleswitch havinga3mm (1/8”)contactseparationinboth
poles,servingonlytheboilerandsystemcontrols.A3pin
UNSWITCHEDsocketmay,alternatively,beused.
Thefuseratingshould be3A.
Forexternalcontrolswiringsee frame25.
Note:theswitchcontactsofanyexternalprogrammer,
roomorfrost thermostatmustbevoltfree.
Connectingaswitchedlivefeedtoexternalcontrols
terminalblockmaybedangerousandwill resultin
seriousdamagetotheboiler.
INSTALLATION