Savio 20/1 MFS User manual

BritishGasTestedandCertified
G.C.No.47 116 01
Thisboilerisfor usewith naturalgasonly
LEAVE THESE INSTRUCTIONS
ADJACENT TO THE GAS METER
BIASIU.K.Ltd
Unit41,PlanetaryRoadIndustrialEstate,NeachellsLane
Willenhall,WolverhamptonWV13 3XB
Telephone:[phone] --- Fax:[phone]
WALL HUNGFANFLUE
ROOMSEALEDGASCOMBINATIONBOILER
MODEL

TABLEOFCONTENTS
boiler20/1 MFS
sect.subjectpageNo.
1General information1..................
1.1Overall view1...........................
1.2Technicaldata2.........................
1.3Description3...........................
1.4Fluepipesoptionalextras3..............
1.5Designprinciplesandoperatingsequence 4
2Generalrequirements6.................
2.1Related documents6....................
2.2Locationofappliance 6..................
2.3Fluesystem6...........................
2.4Gas supply6...........................
2.5Airsupply7............................
2.6Watercirculation(centralheating)7.......
2.7Domesticwater8.......................
2.8Electricalsupply8.......................
3Installation9...........................
3.1Delivery9..............................
3.2Measurementsfor installingtheappliance 9
3.3Assemblingthewall mounting bracket10...
3.4Drillingtheholefor theflue 10.............
3.5Unpackingtheboiler11...................
3.6Mountingtheboiler onthebracket12.......
3.7Mountingtheflue exhaustpipes13.........
3.8Flueterminalguard15....................
3.9Electricalconnections15..................
4Commissioning17.......................
4.1Electricalinstallation17...................
4.2Gas supplyinstallation17.................
4.3Fillingthed.h.w.system17................
4.4Initialfillingofthesystem17...............
4.5Settingthesystempressure 18............
4.6Lightingtheboiler18.....................
4.7Checkingthegaspressureat theburner19.
4.8Checkingthefluesystem20...............
4.9Checkingthefull sequencecontrol20......
4.10 Testingthed.h.w.systemflow20...........
4.11 Selectingthepumpoperatingmodes20....
4.12 Instructingtheuser21....................
5Maintenance 22.........................
5.1General22..............................
5.2Recommendedroutinemaintenance 22.....
6Servicinginstructions23.................
6.1Replacementofparts23..................
6.2Togaingeneralaccess 23.................
6.3Todrainthemaincircuitoftheboiler24.....
6.4Todrainthed.h.w. circuitoftheboiler25....
6.5Setting gaspressures25..................
6.6Reducingthemaximumoutput tomeet
thecentralheating power requirements25. .
6.7Electronicregulationp.c.b.26.............
6.8Full sequencecontrolp.c.b.26............
6.9Overheat thermostat27...................
6.10 Burner27...............................
6.11 Injectors28..............................
6.12 Ignitionand/or detectionelectrodes28......
6.13 Insulationpanels28......................
6.14 Gasmodulator cartridge 28................
6.15 On---off operator coils29..................
6.16 Gasmodulator coil29....................
6.17 Gasvalve 30.............................
6.18 Fanandventuridevice 30.................
6.19 Airpressureswitch31....................
6.20 Main heatexchanger31...................
6.21 Maincircuit temperatureprobe 31..........
6.22 Pump31................................
6.23 Maincircuitflowswitch32.................
6.24 Pump pressureswitch32.................
6.25 Temperature---pressuregauge 33..........
6.26 By---pass 33.............................
6.27 Automaticair releasevalve 33.............
6.28 Expansionvessel33......................
6.29 Safetyvalve 34...........................
6.30 3---wayvalve 34..........................
6.31 D.h.w.heatexchanger35.................
6.32 D.h.w.temperatureprobe 37...............
6.33 D.h.w.flowswitch37.....................
6.34 Waterunit38............................
6.35 O---ringspositiononthed.h.w.heatexch.40
7Fault finding41..........................
7.1Faultfinding diagrams41.................
7.2Usingthefaultfinding diagrams41.........
7.3Specialdefects41........................
7.4Waterleaks41...........................
7.5Difficultyinlightingtheburner41...........
7.6Incorrectcombustion41..................
7.7Tracesofgasor exhaustflues41...........
7.8Appliancecompletelyshutdown42........
7.9Faultof full sequencecontrolp.c.b.44......
7.10 Faultond.h.w.--- c.h.switching46.........
7.11 Faultonmodulation48....................
8Electricdiagrams50.....................
8.1General wiringlayout50..................
8.2Functionalflowdiagrams51...............
9Shortsparepartslist 56.................

1GENERALINFORMATION
1
rev. 17.09.93
1.1 Overall view
22
1
2
3
4
12
7
34
8
15
(16)
(17)
9
10
11
21
14
23
Front view Rear view
36
26
35
33 30 282932 31
20
2524
18
5
19
13
6
27
1Main heatexchanger
2Manual ventcock
3Combustionchamber
4Burner
5Overheat thermostat(probe)
6Detectionelectrode
7Maincircuitflowswitch
8Maincircuit temperatureprobe
9Thermometerprobe
10 Pump
11 Pump plug
12 D.h.w.flowswitch
13 Pressuretestpointformeasuringoutletpressureat
thegasvalve
14 Pressuretestpointfor measuringinletpressureat
thegasvalve
15 Controlpanel
16 Electronicregulationp.c.b.*
17 Full sequencecontrolp.c.b.*
18 Wiring diagram
19 Gasvalve
20 Gasmodulator
21 Ignitionelectrode
22 Fan
23 Venturidevice
24 Fluegas sampling point
25 Airpressureswitch
26 Expansionvessel
27 Databadge
28 Gasinlet
29 Centralheating(c.h.)water return
30 C.h.waterflow
31 Domestichotwater (d.h.w.)inlet
32 D.h.w.outlet
33 3---wayvalve
34 D.h.w.heatexchanger
35 D.h.w.temperatureprobe
36 Automaticair releasevalve
37 Safetyvalve
38 Divertor on3---wayvalve
39 Injector
40 Pump pressureswitch
41 D.h.w.filter
42 D.h.w.flow limiter
43 By---pass
44 Maincircuitdrainagecock
45 D.h.w. circuitdrainagecock
46 Airintake
47 Flueoutlet
*componentenclosedinthecontrolpanel.

Generalinformation
2rev. 17.09.93
1.2 Technical data
Heatinput:
max28,74 kW98 080 Btu/h
min12,40 kW42 317 Btu/h
Heatoutput:
max23.25 kW79 344 Btu/h
min8,71 kW29 274 Btu/h
Centralheating
Operatingtemperature:
max85 °C
min35 °C
Working pressure
max3bar43,5p.s.i.
Watercontent6,25 lts.1,37 gals.
Builtinexpansionvessel:
Totalcapacity7,5lts.1,65 gals.
Pre---chargepressure 0,7bar10,1p.s.i.
Availableheadat1000 litres/hr (220 gals/hr)
3,2mw.g.126 insw.g.
Temp.differencefor
flowandreturn20 °C
Flowrateofwater
throughtheappliance1 000 lts./h220 gals./h
Maxpermissiblecoldwatercapacitywithoutadditional
expansionvessel*71 lts.15,6gals.
Domestichotwater
Operatingtemperature:
max65 °C
min37 °C
Working pressure:
max10 bar145 p.s.i.
min0,2bar2,9p.s.i.
Watercontent0,38/lts.0,08 gals.
flowrate:
min2,0lts./min0,4gals./min
30 °Crise 11,1lts./min2,4gals./min
35 °Crise 9,5lts./min2,0gals./min
40 °Crise 8,3lts./min1,8gals./min
Gasrequirements
maxgasrate 2,79 m3/h98,5ft3/h
mingasrate 1,04 m3/h36,7ft3/h
Inletpressure 20 mbar7,9inw.g.
Burnerpressure:
max9,7mbar3,9inw.g.
min1,4mbar0,6inw.g.
Burnerinjectors12 x1.35
Componentdetails
Gascontrol valveSIT827 nova
BurnerPolidoro
Electricaldata
Electricalsupply240 V~
Frequency50 Hz
Powerconsumption150 W
Externalfuserating3A
InternalfuseratingF1 0,08 AT**
InternalfuseratingF2 1,6AT**
Connections
Gasconnection15 mm o.d.
c.h.flow22 mm o.d.
c.h.return22 mm o.d.
D.h.w.inlet15 mm o.d.
D.h.w.outlet15 mm o.d.
Safetydischargepipe 15 mm o.d.
Fluepipes specifications
Outerdiameters:
flue exhaustpipe 60 mm 2,36 ins
Airintakepipe 100 mm 3,93 ins
Standardlength850 mm 33,46 ins
Maximumlength*** 3 000 mm 118,11 ins
Otherspecifications
Height967 mm 38,1ins
Width400 mm 15,7ins
Depth370 mm 14,5ins
Dryweight50 kg110 lb
*If requiredanexternalexpansionvesselcanbefitted
** Sparefusesareavailablein housingofthe electronicregulationp.c.b.
*** Usingoneormorehorizontallyelongatedfluepipeskit(see sect.1.4).

Generalinformation
3
rev. 17.09.93
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500
14,8
4,4 5,13,62,92,21,50,70
lts./h
gals./min5,54,74,03,32,51,81,10,4
13,1
11,5
9,8
8,2
6,6
4,9
3,3
1,6
0
441,1
392,4
343,4
294,3
245,2
196,2
147,1
98,1
49,3
0
mbarft.headmw.g.
fig.1.1
Availablepumphead
Thecurveinfig.1.1showsthewaterpressure(head)
availabletothecentralheating(c.h.)circuitasafunc-
tionof flow;theloadloss oftheappliancehasalready
beensubtracted.
1.3 Description
7
22
3
1
4
2
13
10
37
12
19
14
36
23
33
26
34
25
38 43 41
44
42
30
46
31
47
2928 32
39
45
24
40
fig.1.2
Theboiler20/1 MFSisacombinedcentralheating
(c.h.)and domestichotwater (d.h.w.)appliance.
Itisproducedasaroomsealedcategoryappliance
suitablefor wall mountingapplicationsonly.
Thisboileris suitableonly for sealedsystems.
Itincorporates:
--- full sequence electronicignitionsystem
--- fanpoweredflueoutletwithanannularco---axial
combustionairintakewhichcanberotatedthrough
360 degrees
--- circulating pump
--- expansionvessel
--- temperatureand pressuregauge
--- safetyvalve
--- 3---wayvalve
1.4 Flue pipes optional extras
Thefollowingitemsareavailable.
Therespectivemountinginstructionsareincludedin
thecartoncontainingthepartsofthekit.
Horizontallyelongatedfluepipes
fig.1.3
Morethanonesectionmaybeused butthetotallength
ofthe exhaustductmustnotexceed3m(9,84 ft).
Everysectionallowstoextendtheductby825 mm
(32,48 ins).

Generalinformation
4rev. 17.09.93
Supplementaryelbow
fig.1.4
Asinglesupplementaryelbowonly,canbeusedduring
installation:thelengthofthe exhaustduct(standard
elbow+thesupplementaryelbowincluded)mustnot
exceed1800 mm (5,9ft).
Verticallyelongatedfluepipes
fig.1.5
Thekitmarkedverticallyelongatedfluepipesallowsto
risetheaxisofthehorizontalpartofthe exhaustduct.
1.5 Design principles and operating
sequence
Watersystemdesign
Thebasicpurposeofaboileristogenerateheat
throughthecombustionofgasandtodirect theheat
throughawatercircuit,asrequired.
Acombination---typeapplianceallowstheheat tobe
usedeitherfor heatingthe environmentandforheating
hotwaterfor domesticuse.
Mainwatercircuit
Thisisaninternal watercircuitintheappliancewhich
passesthroughthemain heatexchangerandabsorbs
heatdirectly fromthecombustionofgas.Thewaterin
thiscircuitisthesameasthewaterthatiscirculated by
thepumpandflowsthroughthec.h.system.
Thepathofthewaterinthemainwatercircuitcanbe
changed bya3---wayvalve.Themainwatercircuitis
connectedtothec.h. circuitduringoperationwiththe
c.h.system(see fig.1.6).
Main heat exchanger
Maincircuit
By---pass
Pump
C.h.circuit
flowswitch
fig.1.6
Duringoperationasad.h.w.heater,themainwatercir-
cuitisdirectedthroughthed.h.w.heatexchanger (see
fig.1.7).
Main heat exchanger
Flowswitch
By---pass
Pump
D.h.w.heat
exchanger
D.h.wflow
switch
fig.1.7
Also,aby---pass valveisinstalledinthemainwatercir-
cuit.Theby---pass valveassuresanadequatewater
flowthroughthemain heatexchanger regardless of
waterflowconditionsinthewatercircuit,thusavoiding
damageduetotemperaturevariations.
Safetydevices
Inbothc.h.andd.h.w.modessafeoperatingisensured
byapump pressureswitchandaflowswitchonmain
watercircuit.
Ifthepressureinthemainwatercircuitisinsufficientthe
pump pressureswitchdisconnectsthesupplytothe
pump.
Iftheflowrateinthemainwatercircuitisinsufficientthe
flowswitchonmainwatercircuitdisconnectsthesup-
plytothefull sequencecontrolp.c.b.
Inbothcasestheboileris stoppedinordertoprevent
damages.
Aoverheat thermostatdisconnectsthetwoON---OFF
operatorsonthegasvalve; asaresult,theburneris
shutdownandtheshut-downwarninglightwillappear.
Asafetyvalveisprovidedto relieve excess pressure
fromthemaincircuit.
Theapplianceisequippedwithasafetysystem(venturi
deviceandairpressureswitch)whichsensestheveloc-
ityofthe exhaustflues.If theairpressureswitchdoes

Generalinformation
5
rev. 17.09.93
notsensethecorrectvelocity,theburnerwill shut
down.
Operatingsequenceoncentralheatingmode
Thefunctionswitchmustbesetonposition.
Thewaterinthemaincircuitis sent tothec.h.system
whenthe3---wayvalveisinthec.h.position.Inthiscon-
figuration,thedivertor isintheupperpositionandthe
d.h.w.heatexchangercircuitiscutout.
Theapplianceiscontrolledbyanelectronicthermostat;
waterdeliverytemperaturecanbeadjustedfrom35°C
to85 °C.
When heatisrequested,acommandreachesthefull
sequencecontrolp.c.b.;thiscommandstartsthefan,
whichswitchestheairpressureswitch.Aftertheair
pressureswitch hasbeenswitched,thecombustion
chamberispurgedofanyresidualunburnedgassesfor
afewseconds.Next,thelightingcyclebeginswitha
sparkfromtheignitionelectrode; at thesametime,
electricalpowerisfedtothetwoON---OFFoperatorson
thegasvalve.
If theflamedetectionelectrodedoesnotsensethe
flamewithin4secondsfromthebeginningofthecycle,
thefull sequencecontrolp.c.b.interruptsthelighting
cycle,the electricsparkis shutoff andthepowerisdis-
connectedfromthetwoON---OFFoperatorsonthegas
valve; asaresult,theburneris shutdown.
At thispoint,theshutdownwarninglightappearsand
theresetpush---buttonmustbepressedto restart the
lightingcycle.
If thedetectionelectrodesensesflameswithin4sec-
ondsfromthebeginningofthecycle,thefullsequence
controlp.c.b.interruptsthe electricsparksandholds
theburneralight.
At thesametime,thetemperatureoftheheatingcircuit
ismeasuredbythemaincircuittemperatureprobeand
thistemperatureiscomparedwiththevaluesetonthe
c.h.temperatureadjustment( ).
Afterlightinghasbeenaccomplished,theamountof
flowfromthegasvalveisdetermined bythe electronic
regulationp.c.b.:
--- whenthetemperatureofthec.h.waterisless than
thepresettemperaturebya?tvalue(differencebe-
tweenoutputandinput temperature)between6°C
and15 °C,theappliancewillsupplyheating power
whichrangesfrom35 to100%ofitsmaximumca-
pacity;
--- whenthetemperatureofthec.h.waterisless than
thepreset temperaturebya?tvaluewhichisless
than6°C,theappliancewill supplyitsminimum
heating power (35%ofitsmaximumheating
power);
--- iftheminimumpowerisgreaterthantheheat
emittedfromtheradiators,theburnerwill shut
down.
Heating powercanbevariedfrom35 to100%ofthe
maximumrated power.
Operatingsequenceond.h.w.mode
Wheneverad.h.w.tapisopened,thed.h.w.flowswitch
onthed.h.w.systemisactivatedandasignalis sent to
the electronicregulationp.c.b.This signalmovesthe
shutter onthe 3---wayvalveandthusclosesthec.h.
watercircuitandopensthed.h.w.heatexchangercir-
cuit.
Theburnerwilloperateatnominalpower,oratapower
ratingwhichkeepsd.h.w.at theconstant temperature
desired(aslongasthedemandforheatingpowerdoes
notexceedthenominalpowersupplied bytheboiler).
Thus,burner operationdependsontheamountof
d.h.w.usedandthetemperaturewhichhasbeenseton
thed.h.w.temperatureadjustment( ).
D.h.w.onlyoperation
Whenthefunctionswitchissetonposition,thec.h.
adjustmentsystemisdeactivated,the 3---wayvalveis
nolongeractuated,theshuttercloseswaterdeliveryto
thec.h. circuitandopensdeliverytothed.h.w.heatex-
changer.Whend.h.w.iswithdrawnfromthed.h.w.sys-
tem,operationoftheappliancewill bethesameas
operationwiththefunctionswitchsetonposition.

2GENERALREQUIREMENTS
6rev. 17.09.93
Thisappliancemustbeinstalledbyacompetent
personinaccordancewiththeGasSafety(installa-
tion&Use)Regulations1984.
2.1 Related documents
Theinstallationofthisappliancemustbeinaccordance
withtherelevantrequirementsoftheGasSafety(Instal-
lation&Use)Regulations(1984),theLocalBuilding
Regulations,thecurrentI.E.E.WiringRegulations,the
by---lawsofthelocal waterundertaking,andinScot-
land,inaccordancewiththeBuildingStandards(Scot-
land)Regulation.Healthandsafetydocumentn°635
”Electricityatworkregs.1989”.
Itshould beinaccordancealsowiththefollowingBrit-
ishStandardCodesofPractice:
Lowpressureinstalla-
tionpipesBS6891 1988
Boilersofratedinput
notexceeding60 kWBS6798 1987
Forcedcirculation hot
watersystemsBS5449 1990
Installationofgashot
watersuppliesfor do-
mesticpurposes
(2ndfamilygases)BS5546 1990
FluesBS5540---1 1990
AirsupplyBS5540---2 1989
2.2 Location of appliance
Theappliancemaybeinstalledinanyroomor internal
space,althoughparticularattentionisdrawntothere-
quirementsofthecurrentI.E.E.WiringRegulations,
andinScotland,theelectricalprovisionsoftheBuilding
RegulationsapplicableinScotland,withrespect tothe
installationofthecombinedapplianceinaroomcon-
tainingabathor shower.
Wherearoom--sealedapplianceisinstalledina
roomcontainingabathorshower,anyelectrical
switchorappliancecontrol,utilisingmainselectric-
ityshouldbesosituatedthatitcannotbe touched
byaperson usingthebathorshower.
Thelocationmustpermitanadequatespaceforservic-
ingandaircirculationaroundtheappliance
(see fig.2.1).
a
b
c
d
a
b
c
d
155 mm
130 mm
500 mm
50 mm
6,1ins
5,1ins
19,7ins
1,9ins
fig.2.1
Thelocationmustpermit theprovisionofanadequate
flueandtermination.
For unusual locations specialproceduresmaybe
necessaryandBS6798---1987givesdetailedguidance
onthisaspect.
Acompartmentusedtoenclosetheappliancemustbe
designedspecifically for thispurpose.
Thisapplianceisnotsuitablefor externalinstallation.
2.3 Flue system
Theprovisionfor satisfactory flueterminationmustbe
madeasdescribedinBS5440---1.
Theappliancemustbeinstalledsothattheflueterminal
isexposedtoexternalair.
Itmustnotbeinstalledsothat theterminaldischarges
intoanotherroomorspaceasanouthouseorlean---to.
Itisimportant that thepositionoftheterminalallowsa
free passageofairacross atall times.
Theterminalshould belocatedwithdueregardfor the
damageor discolorationthatmightoccurtobuilding
productsinthevicinity.
Incoldand/or humidweatherwatervapourmaycon-
denseonleavingtheflueterminal;the effectofsuch
”steaming” mustbeconsidered.
Theminimumacceptablespacingfromtheterminalto
obstructionsandventilationopeningsarespecifiedin
fig.2.2.
A
BC
D
E
F
G
HIJ
KL
F
G
Terminalpositionmm
ADirectlybelowaopenwindoworotheropening300... .....
B Belowgutters,solid pipesordrainpipes75... ............
CBeloweaves200... ...................................
DBelowbalconiesorcarportroof200... ..................
EFromverticaldrainpipesandsoilpipes75... .............
F Frominternalorexternalcorners300... .................
GAbovegroundorbelowbalconylevel300... .............
HFromasurfacefacingaterminal600... ..................
IFromaterminalfacingaterminal1 200.... ...............
JFromanopeninginthecarport... (e.g.door,window)intodwelling1 200...............
KVerticallyfromaterminalinthesamewall 1 500... ........
LHorizontallyfromaterminalinthesamewall 300... ........
fig.2.2
2.4 Gas supply
Gasmeterisconnectedtotheservicepipebythelocal
gasregionor alocalgasregioncontractor.
If thegas supply for theboilerservesotherappliances
ensurethatanadequatesupplyisavailablebothtothe

Generalrequirements
7
rev. 17.09.93
boilerandtheotherappliancewhentheyarein useat
thesametime.
Pipeworkmustbeofadequatesize.Pipesofasmaller
sizethantheboilerinletconnectionshouldnotbeused.
Installationpipes should befittedinaccordancewith
BS6891---1988andthecompleteinstallationshouldbe
testedfor soundness.
2.5 Air supply
Theroominwhichtheboilerisinstalled doesnotre-
quireapurposeprovidedairvent.
If installedinacupboardor compartment,ventilationis
also requiredfor cooling.
Recommendationsfor airsupplyaredetailedin
BS5440---2.
2.6 Water circulation (central heating)
DetailedrecommendationsaregiveninBS6798---1987
andBS5449---1 1990; thefollowingnotesaregivenfor
generalguidance.
Pipework
CoppertubingtoBS2871---1 1977isrecommendedfor
waterpipes.Jointingshouldbeeitherwithcapillarysol-
deredor withcompressionfittings.
Wherepossiblepipesshouldhaveagradient toensure
airiscarriednaturallytoair releasepointsandwater
flowsnaturallytodraintaps.
Theappliancehasabuilt---inautomaticair release
valveanyway,itshould be ensuredasfaraspossible
that theapplianceheatexchangerisnotanaturalcol-
lecting pointfor air.
Exceptwhereprovidingusefulheat,pipes should be
insulatedtopreventheatloss andtoavoidfreezing.
Particularattentionshould bepaidtopipespassing
throughventilatedspacesinroofsandunderfloors.
By--pass
Theapplianceincludesanautomaticby---pass valve
whichprotectsthemain heatexchangerincaseofre-
ducedorinterruptedwatercirculationthroughtheheat-
ingsystemduetotheclosingofthermostaticvalvesor
cock---typevalveswithinthesystem.
Theby---pass iscalibratedtoassureaminimumflowof
500---600 lts/hrthroughthemain heatexchanger.
Systemdesign
Thisboileris suitableonlyforsealedsystems.
Atypical lay---outisillustratedinthefollowingfigure.
Gas supplypipe
Draintap
(atlowestpoint)
Coldwaterinlet
Sink
Shower
fig.2.3

Generalrequirements
8rev. 17.09.93
Thesemustbelocatedinaccessiblepositionstopermit
thedrainingofthewholesystems.Thetapsmustbe
atleast15 mm nominalsizeandmanufacturedinac-
cordancewithBS2870 1980.
Air releasepoints
Thesemustbefittedatall highpointswhereairwill
naturalcollectandmustbesitedtofacilitatecomplete
fittingofthesystem.
Theappliancehasanintegralsealedexpansionvessel
toaccommodatetheincreaseofwatervolumewhen
thesystemisheated.
Itcanacceptupto7lts(1,5gals.) ofexpansionwater.
If theheatingcircuithasan unusuallyhighwatercon-
tent, calculatethetotalexpansionandadd additional
sealedexpansionvessel withadequatecapacity.
Mainswaterfeed:centralheating
Theremustbenodirectconnectiontothemainswater
supplyeventhroughanonreturnvalve,without theap-
provaloftheLocalWaterAuthority.
Filling
Amethodfor initially fillingthesystemandreplacing
waterlostduringservicingmustbeprovidedandit
mustcomplywithlocal waterauthorityregulations.
Apossiblemethodis showninfig.2.4.
C.h.returnColdwaterinlet
Temporaryhose
Wall mounting
bracket
fig.2.4
Theinstallershouldensurethatnoleaksexistasfre-
quentfillingofthesystemcouldcauseprematurescal-
ingoftheheatexchanger.
2.7 Domestic water
Thedomesticwatermustbeinaccordancewiththerel-
evantrecommendationsofBS5546.Coppertubingto
BS2871---1isrecommendedfor watercarrying pipe-
workandmustbeusefor pipeworkcarrying potable
water.
2.8 Electrical supply
Warning,thisappliancemustbe earthed.
External wiringtotheappliancemustbecarriedoutby
acompetentpersonandbeinaccordancewiththecur-
rentI.E.E.Regulationsandlocalregulationswhich
apply.
Theboiler20/1 MFSis suppliedfor connectiontoa
240 V~50 Hzsupply.Thesupplymustbefusedat3A.
Themethodofconnectiontotheelectricitysupplymust
facilitatecomplete electricalisolationoftheappliance
bytheuseofafused doublepoleisolatorhavingacon-
tactseparationofatleast3mm inall polesor alterna-
tively,bytheuseofa3Afusedthree pinplugandun-
switchedshutteredsocketoutletbothcomplyingwith
BS1363.
Thepointofconnectiontotheelectricitysupplymustbe
readilyaccessibleandadjacenttotheapplianceexcept
weretheapplianceisinstalledinabathroomthismust
besitedoutsidethebathroom.

3INSTALLATION
9
rev. 17.09.93
3.1 Delivery
Therewill be3items:
1theboilerfullyassembled;
2thewall mounting bracketwithcocksand pipes;
3Standardflueassemblywhichincludefluepipesand90°elbow.
3.2 Measurements for installing the appliance
a--- safetyvalvedischargepipe
b--- gas
c--- c.h.water return
d--- c.h.waterflow
e--- d.h.w.inlet
252 (9,92)
abcde
Front view Top view
187 (7,36)213 (8,38)
400 (15,7)
853 (33,6)
f
f--- d.h.w.outlet
61 (2,40)
25
(1)54 (1,12)49 (1,93)45 (1,77)40 (1,57)145 (5,71)
83 (3,27)
78 (3,07)
122 (4,80)
228 (8,97)
50 130
(5,12)(2)
155 (6,1)500 (19,7)
Clearances required for servicing
All measurementsareinmillimetres(inchesinbrackets)
50 130
(5,12)(2)
180 (7)
Wall mounting bracket
Wall mounting bracket

installation
10 rev. 17.09.93
3.3 Assembling the wall mounting bracket
Thecartonmarkedwall mountingbracketcontainsthefollowing:
1mounting bracket;
2 1/2” cockfor d.h.w.inlet;
3 3/4” cocksfor c.h.flowandreturn;
4 1/2” nipplesfor d.h.w.andsafetyvalveoutlet;
5 3/4” gaskets;
6 3/4” nutsfor mounting3/4”cocksand gaspipe;
7 3/4” nipplefor c.h.return;
8ø15 mm o.d.pipefor safetyvalvedischarge;
9ø22 mm o.d.pipefor c.h.returnwith3/4” connector nut;
10 ø22 mm o.d.pipefor c.h.flow with3/4” connector nut;
11 ø15 mm o.d.pipesfor d.h.wcircuit;
12 ø15 mm o.d.pipefor gasinlet;
13 c.h.returnpipewithsafetyvalveconnection;
14 safetyvalve;
15 1/2” nutsfor mountingthe 1/2” cockandnipple;
16 1/2” gaskets;
17 1/2” connector nuts;
18 15 mm compressionfittingcockfor gasinlet.
18
2
3
5
6
1
8
11
10
9
12
14
13
15
16
17
7
4
--- Positionthemounting bracketonthewall.Useaspiritlevelto
makesurethat thesupportislevel;
--- marktheattachmentpointsthroughtheholesindicated;
--- removethewall mounting bracketand drill holesinthewall at
thepointsmarked;
--- usescrewswithwall plugsø 8mm toattachthewall mounting
bracket towall;
1
3.4 Drilling the hole for the flue
--- Drill aholewithadiameter ofatleast110 mm (4,33 ins)inthe
wall;for correctpositionsee sect.3.2.
Drill theholeinthedirectionoftheflue exhaustpipesothat the
ductwill haveaslightdownwardinclinationtotheoutside;
--- mount thecocksandfittingsonthebottomofthewallmounting
bracketandtightenwiththenuts;
--- usetheconnector nutstoconnect thepipestotheir respective
cocks.
Besuretousethecorrectgasketswheninstallingthepipes;
--- connectvalvesand pipesfromright toleft;
Wall mounting bracket(1)
(topview)
423712
15
5
6
16
17
1113 10

Installation
11
rev. 17.09.93
--- mountthecockforgasinlet(18)andthe3/4”cockforc.h.return
(3).Besuretousethecorrectgaskets.
--- mount thepipefor c.h.return(9);
Wall mounting
bracket(1)
(frontview)
3
5
18
13
12
9
--- mount thesafetyvalve(14) onthec.h.returnpipe(13)witha
1/2” gasket.Thevalvemustbemountedwithitsoutlet towards
thelefthand.
--- Mount the 1/2” nipple(4)andthepipefor thesafetyvalvedis-
charge(8)withthecorrectgasketsasindicated.Connectdis-
chargepipetoenableit todischarge externallyatlow level;
--- connectcockstocorresponding pipeswithintheappliance
usingthecorrectwashers supplied;
--- completetheinstallationconnectingthepipestotheotherparts
oftheplant.Makewaterheatingand gasconnectionstothe
appliance.
8
17
16
4 14
4
Towardsthe
safetyvalve.
13
3.5 Unpacking the boiler
--- Openthesideofthecartonmarkedopeningside;
--- overturnthecartonkeepingtheflapsopen;

installation
12 rev. 17.09.93
--- liftupthecarton;
--- rest theboiler onthefloor andremovethepolystyreneguards.
3.6 Mounting the boiler on the bracket
--- Removetheprotectioncapsfromthepipesontheboiler;
--- carefullycleanthecocksandconnectionsmountedonthewall
mounting bracket;
--- hangtheapplianceonthebracket;
--- removethelowerprotectionplate(sect.6.2);
--- install connectorsonthepipes(usetheoriginalgaskets
suppliedwiththewall mounting bracket);
--- tightentheconnectors securely;
--- re---install thelowerprotectionplate.

Installation
13
rev. 17.09.93
3.7 Mounting the flue exhaust pipes
Openthecartonmarkedstandardflue exhaustpipes.
Itcontainsthefollowing:
19 flue exhaustpipewithwind---resistant terminal;
20 pipesupport
21 self---tappingscrews3,5x19 mm;
22 springsfor thetightening band;
23 gasket tightening band;
24 gasketwhichsealsthe elbowtotheflueduct;
25 gasketwhichsealsthe elbowtothesurfaceoftheappliance;
26 self---tappingscrews4,8x13 mm;
27 90°elbow;
28 suctionpipe--- ø100 mm;
29 wall gaskets;
30 self---tappingscrews4,8x13 mm.
27
28
26
25 24
21
23
19
29
22
30
20
Cuttingthe flue exhaustpipes
Ifyourparticularinstallationrequiresyoutoshortentheduct,seethe
followinginstructionsfor cuttingmeasures.
If you needtoextendtheflueductor changeitsdirection,optional
kitsareavailable(sect.1.4).
All measuresareinmillimetres(inchesinbrackets).
Bothpipesmustbecutonthesidefacingthe elbow.
Rear outlet
Ls=Lx+173 (6,81)
Le=Lx+322 (12,68)
Lsmax=775 (30,51)
Lemax=928 (36,53)
6(0,23)
Le
Lx
Wall mounting
Ls20 (0,78)
61 (2,40)
bracket
Rightsideoutlet
L1min=130 (5,11)
Ls=Lx+L1+134 (5,27)
Le=Lx+L1+287 (11,30)
Lsmax=775 (30,51)
Lemax=928 (36,53)1
L
6(0,23)Ls
Le
Lx20 (0,78)
61 (2,40)
Wall mounting
bracket
Leftsideoutlet
L2min=50 (1,97)
Ls=Lx+L2+108 (4,25)
Le=Lx+L2+261 (10,27)
Lsmax=775 (30,51)
Lemax=928 (36,53)2
L
6(0,23)
Ls
Le
Lx
20 (0,78)
61 (2,40)
Wall mounting
bracket

installation
14 rev. 17.09.93
Mounting operations
--- Insert the exhaustpipeintothesuctionpipesothat thewind---
resistantterminalcontactstherimwhichislocatedontheinside
ofthesuctionpipe; 19
28
--- introducethepipeassembly,togetherwithwind---resistant ter-
minal,intotheholeyou havedrilledinthewall.
A20mm (0,78ins)lengthofthesuctionpipemustprotrudefrom
thewall;
--- mount thewall gasketsonthepipe;
--- positionthegaskets sowhenthepipeispulled backtheymake
goodsealagainst thewall;
19
28
20 mm
(0,78 ins)
2929
--- insert thepipesupport;
--- insert thesuctionpipeonthetightening band;
--- install thegasketwhichsealsthe elbowtotheductbyplacing
thelargerinternaldiameter ofthegasketontheairsuctionpipe;
19
28
24
20
--- placethegasketonthesurfaceoftheappliance; 25
--- installtheelbowonthesupport;besurethatthefollowingcondi-
tionsaremet:
makesurethat theflue exhaustpipeisfirmlyinsertedintothe
elbow;
besurethatadistanceof6mm (0,23ins)hasbeenleftbetween
thesuctionpipeandthe elbow.
Thepurposeofthis spaceistoallowthe elbowtoberemoved
for maintenanceafterthepipehasbeenenclosedinthewall.
Therefore,neverpushthesuctionpipeintothe elbow;
19
28
24
27
6mm
(0,22 ins)
--- usethescrewstoattachthe elbowtothesurfaceofthe
appliance;
--- usethegasketyoupreviouslyinstalledtosealtheconnection
betweenthe elbowandtheduct;
--- usethegasket tightening bandwithspringsandscrewsto
tightenthegasket;
--- maketwoø 3,7mm (0,14 ins)holes;oneonthe elbowandthe
other ontheintakepipeat thesamelevelastheholesonthe
gasket tightening band;
--- usethescrews suppliedwiththekit toconnect the elbow,the
bandandthepipetogether.
26 27 23
30
21

Installation
15
rev. 17.09.93
3.8 Flue terminal guard
Wherecodesofpractisedictateasuitableguardshould befitted.
Asuitableguardisavailablefrom:
TOWERFLUECOMPONENTS
MorleyRoad
Tonbridge
KentTN9 1RA
Whenordering guard,quoteappliancemodelnumber.
Theguardshould befittedcentrallyovertheterminal.
3.9 Electrical connections
Connectingtothe electricitysupply
WARNING-- THISAPPLIANCEMUSTBE EARTHED
Theapplianceisdeliveredwithaflexiblecablefor electricalsupply.
Thecableallowsthe electricalconnectionasdetailedinsect.2.8.
Theelectricalsupplycableisstoredinsidetheapplianceinthelower
rightzoneofthecontrolpanelanditismarkedwithalabelstuckon
itsedge.
Togainaccesstotheelectricalsupplycable,removethefrontpanel
ofthecaseandlowerthecontrolpanelasexplainedinsect.6.2.
--- Pass thecables(electricalsupplycableandexternalcontrols
cable)throughtherubbergrommetsfittedonthebracketindi-
cated;
--- makesureallcablestotheappliancearedetailrouteawayfrom
sharpedgesandhotsurfaces.
--- fit thelowerprotectionplate.
Replacingthe electricalsupplycable
To replacethe electricalsupplycableproceedasfollows:
--- removethefrontpanelofthecase(sect.6.2)
--- unscrewthesixscrews”A”andremovetheserviceaccess
doors;
C
C
CC
C
C
--- loosenthescrews”B”ofthemainterminalblock(markedLand
N)andthescrew”C” ofthe earthterminal;
--- loosenthescrews”D” and pull thecableremovingitfromthe
clampseat;
--- lowerthecontrolpanel(sect.6.2);C
B
D D

installation
16 rev. 17.09.93
--- unscrewthefourscrews”E” andremovethecover onthefull
sequencecontrolp.c.b.
--- removethecableslidingit throughtherubbergrommet”F”;
--- insert thenewcable.APVCinsulatedflexiblecablemustbe
used.Itmustbea3coreofsize 0.75 mm2(24x0.2mm)toBS
6500 table 16;
--- connect thecabletotheterminalsmarkedasfollows:
Screws”B”L---
N--- Brownor Redwire(live) Blueor Blackwire(neutral)
Green/Yellowor Greenwire(earth)Screw”C”
EE
E
E
F
--- Thecablemustbesecuredandconnectedsothatshouldthe
cableslipfromtheanchoragethecurrentcarryingconductors
becometautbeforethe earthingconductor.
Connectingthe externalcontrols
(roomthermostat,timeclock)
WARNING-- EXTERNALCONTROL LINESMUSTBEINSU-
LATEDFROMELECTRICALSUPPLYLINES.
Ifcontrolsexternaltotheappliancearerequired,designoftheexter-
nalelectricalcircuits should beundertakenbyacompetentperson.
Itisessentialthatallexternalcontrolcircuitsandwiringiswiredfrom
thesame electricalisolator as servestheappliance.Factory fitted
internalwiringmustnotbedisturbedwhenwiringexternalcontrols.
Toconnectanexternalcontrol:
1removethefrontpanelofthecaseandlowerthecontrolpanel
(see sect.6.2);
2openthe externalcontrolboxremovingthetwoscrewsindi-
cated;
3removethe electriclinkbetweenTT andTConthe externalcon-
trolterminalblock;
4connect the externalcontrolas showninthefollowingfigures.
Ifrequested,externalcontrolmustbe earthed.
Timeclocks shouldbevoltage free connections.
Connectinga”simplecontact” roomthermostat.
TT
TR
TC
Externalcontrolbox
Connectingaroomthermostatwithdelayresistor.
TT
TR
TC
Externalcontrolbox
Connectingatimeclock.
Donotinsertanyinternal linksontimelocks.
Doingsomayinvalidate guarantee.
TT
TR
TC
ExternalcontrolboxM
L
N

4COMMISSIONING
17
rev. 17.09.93
4.1 Electrical installation
Preliminaryelectricalsystemcheckstoensureelectricalsafetyshall
becarriedoutbyacompetentperson.I.e.polarity,earthcontinuity,
resistancetoearthandshortcircuit.
If afaulthasoccurredonappliancethefaultfinding procedureshould
befollowedas specifiedundertheservicingsectionofthisdocument.
4.2 Gas supply installation
1Inspect the entireinstallationincludingthegasmeter,testfor
soundness and purge,all asdescribedinBS6891;
2openthegascock(drawnwiththeknobin”open” position) on
theapplianceandcheckthegasconnector ontheappliancefor
leaks.
4.3 Filling the d.h.w. system
1Closeall hotwaterdraw---off taps;
2openthecoldwaterinletcockasindicated;
3slowlyopeneachdraw---off tapandcloseitonlywhenclear
water,free ofbubbles,flowsout.
4.4 Initial filling of the system
1Opencentralheatingflowandreturncocksasindicated;
2unscrewthecapontheautomaticair releasevalveonefull turn
andleaveopenpermanently;
3closeall air releasevalvesoncentralheatingsystem;
4graduallyopenstopcockat thefilling pointconnectiontothe
centralheatingsystemuntil waterisheardtoflow;donotopen
fully;
5openeachairreleasetapstartingwiththelowerpointandclose
itonlywhenclearwater,free ofbubbles,flowsout;
6removethefrontpanelofthecase,thelowerprotectionplate
andlowerthecontrolpanel(sect.6.2);
7purgetheairfromthepump byunscrewingthepump plugindi-
cated;releasethepumpbyturningtherotorinthedirectionindi-
cated bythearrowontheinformationplate;
8closethepump plug;
9continuefillingthesystemuntilatleast1,5bar(21,3p.s.i.)regis-
tersontemperature---pressuregauge;
10 inspect thesystemfor watersoundness andremedyanyleaks
discovered.
11 makesurethat thecontrol lever onthe 3---wayvalve(bottom
sideofappliance)ispositionedtotheright;

Commissioning
18 rev. 17.09.93
Whentheinstallationandfillingarecompletedturnonthecen-
tralheatingsystem(sect.4.6)andrun ituntil the temperature
hasreachedtheboileroperatingtemperature.Thesystemmust
thenbeimmediatelyflushedthrough.
The flushing proceduremustbeinlinewithBS7593:1992Treat-
mentofWaterinDomesticHotWaterCentralHeatingSystems.
Thisproceduremustberepeatedtwicemore.
Duringthisoperationwehighlyrecommendtheuseofacentral
heatingflushingdetergent,whose functionitistodissolveany
foreignmatterwhichmaybeinthesystem.i.e.FernoxSuper-
floc.
Wealsorecommendtheuseofaninhibitorinthesystemsuch
asFernoxMB1universal.
Theaboveoperationcouldsave theinvalidationofyourboilers
guarantee andwill also preventproblemswhichyoumayex-
perienceinthe futureifaninhibitorisnotused.
4.5 Setting the system pressure
Theactualreadingshouldideallybe 1,5bar (21,3psi).
4.6 Lighting the boiler
If externalcontrolsarefitted(e.g.Timeclock,roomthermostat)en-
surethey”call for heat”.
Commissioningoperationswill be easierifcontrolsarediscon-
nectedandterminalsTT andTCarelinked
(see sect.3.9).
1Switchonthemainselectricityandturnthefunctionswitch”A”
asindicated.
Theboilerwillnowgothroughanignitionsequenceandtheburner
will light.
If duringtheignitionattemptperiod(4secs.approx.)theboilerfalls
tolight,thefull sequencecontrolp.c.b.will gotolockoutandthe
shut---downwarninglight”B” will appears.
To reset theboilerdepress theresetpushbutton”C” markedwith
thesymbol:
AB
C