Biasi Unvented Hot Water Cylinders User manual





UnventedHotWaterCylinders
InstallationandMaintenanceInstructions










IMPORTANTNOTETOTHEINSTALLER
Readtheseinstallationandmaintenanceinstructionsbeforecommencing.Unventedcylindersareacontrolledserviceas
definedinthelatesteditionofthebuildingregulationsandshouldonlybefittedbyacompetentperson.
Therelevantregulationsare:EnglandandWales–BuildingRegulationG3;Scotland–TechnicalStandardP3;NorthIreland–BuildingRegulationP5.

Afterinstallationtheinstallermustlefttheinstructionsmanualwiththehouseholder.


unventedhotwatercylinders
installationandmaintenanceinstructionsPage2/20

PRE‐INSTALLATIONSTORAGE
Storetheunitstandinguprightinitsoriginalpackaginginanareafreefromexcessivedamp.

FEATURESOFTHEUNVENTEDCYLINDER:
‐MadefromDuplexStainlessSteelforexcellentcorrosionresistance
‐Strongrust‐proofedsteelcase
‐Highlyinsulatedwithenvironmentallyfriendlyfoam
‐Availableinrangeofsizestosuit‐125L,150L,170L,200L,250Land300litres
‐AllmodelsincludingSolarmodelsareavailableinDirectorIndirectversions
‐Suppliedcompletewithallthenecessarysafetyandcontroldevicesneededtoconnectcoldwatermains
‐Allsafetyandcontroldevicesarepre‐adjusted
‐ Highqualitycontrolsselectedthatcombinehighflowrateperformancewithminimumpressuredropwhichgives
fantasticperformanceinallareas,withgreatimprovementsinareaswithpoorwaterpressure
‐KIWAapprovedforcompliancewiththeWaterSupply(WaterFittings)Regulations1999andBuildingRegulationsG3
&L.
COMESCOMPLETEWITHALLTHEFITTINGSYOUNEEDTOCOMPLETETHEINSTALLATION:
ACCESSORIESDIRECTINDIRECTSOLARDIRECTSOLARINDIRECT
ExpansionVessel3 3 33
Wallmountingkitforexpansionvessel3 3 33
Expansionvesselhose3 3 33
Tundish3 3 33
10wayelectricalbox2 3 33
Highflowrateinletcontrolset3 3 33
Twoportvalve2 3 33
Immersionheater3 3 33
Temp&Pressurereliefvalve3 3 33
Dualthermostat2 3 23
Highlimitstat2 2 33
Installation&MaintenanceInstructions3 3 33


Storagecapacity125L150L170L200L250L300L
Operatingpressure5,5bar
MaxWatersupplypressure10bar
MaxPrimaryworkingpressure3bar
Pressurereducingvalve3bar
Immersionheater3kW/240V,1¾’’,16’’LONG
Expansionvesselchargepressure3bar



unventedhotwatercylinders
installationandmaintenanceinstructionsPage3/20

SITINGTHEUNIT
Thisunitcansupplyoutletsaboveitoratsomedistancefromitbutanyoutletsabovetheunitwillreducetheavailableoutlet
pressureby0.1barforevery1mofheightdifference.Themaximumlengthofthe“deadleg”shouldbeasstatedintheWater
Supply(WaterFittings)Regulations1999G18.7,inparticulartotheareaofmostfrequentuse.

Particularattentionisneededifsittinginagarageoroutbuildingastheunitshouldbeprotectedfromfrost.Allexposed
pipeworkmustbeinsulated.TheunitmustbeinstalledUPRIGHTonaflatbasecapableofsupportingitsweightwhenfull
(pleaseseethetechnicalspecificationsectionforweights).Theminimumrecommendedcupboardsizeis650mmsquare.

Sufficientaccesstoallowmaintenanceofthevalvesshouldbeconsidered.Inadditiontheimmersionheatersare400mmin
lengthandthisdistanceshouldbeconsideredtoallowwithdrawalforservicingifrequired.Thedischargepipeworkfromthe
safetyvalvesshouldfallcontinuouslyandterminatesafely.
SCHEMATICDIAGRAM

WATERSUPPLY
Theperformanceofanyunventedsystemisonlyasgoodasthemainswatersupplyavailable.Tothiseffectthemaximum
possiblewaterdemandshouldbeassessed,withtheknowledgethatthemainssuppliesbothhotandcoldservices
simultaneously.

Thewaterheateritselfoperatesatapressureof3bar,controlledbytheinletcontrolset,andiscapableofdeliveringover50
litresperminute.Thehighqualityinletcontrolsethasbeendesignedtomakethemostoftheflowratesavailable.

Thewatersupplyshouldbecheckedtoensureitcanmeettheserequirements.Ifnecessary,consultthelocalwaterauthority
regardingthelikelypressureandflowrateavailability.
Considerationshouldbegiventoupgradingexisting½”(15mm)coldmainspipeworktoalargersizeiftherecommended
minimumpressure/flowrateisnotbeingachieved.

Note:Ahighstatic(noflow)mainspressureisnoguaranteeofgoodflowavailability.Inadomesticinstallation1.5barand25
l/min.shouldberegardedastheminimum.Themaximummainspressurethattheinletcontrolsetcancopewithis10bar.
Legend:
1.BronzePump
2.NonReturnValve
3.TwoPortValve
4.Temperature&PressureReliefValve
5.ExpansionReliefValve
6.ExpansionVesselwithwallbracket
7.PressureReducingValve
8.IsolatingValve
9.DrainValve(notsupplied)
Note:
Thepressurereducingvalve,non‐return
valveandexpansionreliefvalveare
combinedtogetherintheinletcontrolet.
On125‐170Lsizesthereisnodedicated
secondaryreturnbossandthesecondary
returncircuitshouldbetee’dintothe
coolfeedpipejustabovethedrainelbow.
SECONDARY
FLOW
SECONDARY RETURN CIRCUIT
(200, 250 & 300 LITER SIZES)
PRIMARY
FLOW
DUAL
STAT
PRIMARY
RETURN
1 2
3
4
5
FLEXIBLE HOSE
6
2 7
COLD
MAIN
COLD FEED
BALANCED COLD
CONNECTION
8
9


unventedhotwatercylinders
installationandmaintenanceinstructionsPage4/20

GENERALINSTALLATION
CONNECTINGTOTHECYLINDER
Allofthepipeworkconnectionsonthecylinderare22mmcompressionandsuppliedcompletewithglandnutsandolives,inthe
AccessoryKitbox.Onlyconnect22mmTableXcoppertubetotheseconnections.Cutthetubewithapipecutterandensureno
sharpedgesorburrsprotrude.Slidebothglandnutandoliveontothetubeandpushtubefullyhomeintotheconnection,
ensuringthetubeendfullybottomsontheconnectionrecess.Smeartheouterwalloftheolivewithplumbingpasteand
tightenglandnutcorrectly.
Uponfilling/commissioning,ensureallconnectionsarecompletelywatertight.
Note:Nocontrolorisolationvalveshouldbefittedbetweentheexpansionreliefvalveandthestoragecylinder.Thereliefvalve
connectionsshouldnotbeusedforanyotherpurpose.

COLDMAINSPIPEWORK
Runthecoldmainthroughthebuildingtotheplacewhereistobeinstalled.Takecarenottorunthecoldpipenearhotwater
orheatingpipeworksothattheheatpick‐upisminimized.Identifythecoldwatersupplypipeandfitanisolatingvalve(not
supplied).A22mmBS1010stopcockcantypicallybeusedbuta22mmquarterturnfullborevalvewouldbebetterasitdoes
notrestricttheflowasmuch.Donotuse“screwdriverslot”orsimilarvalves.Maketheconnectiontothecoldfeedofthe
cylinderandincorporateadrainvalve.PositiontheinletcontroljustABOVEtheTemperature&PressureReliefValve(TPRV)
mountedonthesideofthecylinder.Thisensuresthatthecylinderdoesnothavetobedraineddowninordertoservicethe
inletcontrolset.Ensurethatthearrowpointsinthedirectionofthewaterflow.Selectasuitablepositionfortheexpansion
vessel.Mountittothewallusingthebracketprovided.Usetheflexiblehoseprovidedtoconnecttotheinletcontrolgroup.

BALANCEDCOLDCONNECTION
Iftherearetobeshowers,bidetsormonobloctapsintheinstallationthenabalancedcoldsupplyisnecessary.Thereisa22mm
balancedconnectionontheinletcontrolset.

HOTWATERPIPEWORK
Runthefirstpartofthehotwaterdistributionpipeworkin22mm.Thiscanbereducedto15mmand10mmasappropriatefor
thetypeoftapetc.Youraimshouldbetoreducethevolumeofthehotdraw‐offpipeworktoapracticalminimumsothatthe
timetakenforthehotwaterisasquickaspossible.Donotusemonoblocmixertaporshowersifthebalancedcoldconnection
isnotprovided.Outletsofthistypecanbackpressurizetheunitandresultindischarge.Selectasuitablepositionforthe
expansionvessel.Mountittothewallusingthebracketprovidedandconnecttotheinletcontrolsetwiththeflexiblehose
provided.Ensurethatthetopofthevesselisaccessibleforservicing.

PRIMARYCOILCONNECTIONS
Connecttheprimaryconnections(Indirectonly)usingthecompressionconnectionsprovided.Theprimarycircuitmustbe
positivelypumped.Gravitycirculationisnotsuitable.Eitherprimaryconnectionmaybeusedastheprimaryflow.Reheattimes
areidenticaleitherway.Theprimarycircuitcanbeopenventedorsealed,withuptoamaximumpressureof3.5bar.Ifyouseal
theprimarycircuitanadditionalexpansionvesselandsafetyvalveisrequired.TheboilermaybeGas,ElectricorOilbutmustbe
undereffectivethermostaticcontrol.UncontrolledheatsourcessuchassomeAGA’s,backboilers,solidfuelstoves,etc.areNOT
SUITABLE.PleasecontactourTechnicaldepartmentforguidance.Connectthetwoportzonevalve(indirectonly)intothe
primaryflowpipework.Thedirectionofflowarrowshouldbetowardstheprimaryflowconnection.Ontwincoilsolarcylinders
wehaveprovidedanextrathermostatbossshouldyouwishtouseit.Againatwoportzonevalveshouldbefitted(supplied).

SECONDARYCIRCULATION
Canbeusedwithsecondarycirculation.AnappropriateWRASapprovedbronzecirculatorshouldbeusedinconjunctionwitha
non‐returnvalvetopreventbackflow.Onlargesecondarycirculationsystemsitmaybenecessarytoincorporateanextra
expansionvesselintothecircuittoaccommodatetheincreasedsystemwatervolume.Secondarycirculationshouldbeavoided
onDirectelectricallyheatedunitsbeingusedonoff‐peakelectricitytariffs.
Asecondaryreturnbossisfittedasstandardon200L,250Land300Lunits.Onsmallersizes,teeintothecoldfeedpipeabove
thedrain.

IMMERSIONHEATERS
Onlyimmersionheaterswithathermalcutoutmaybeused.Tohelpensurethis,theimmersionheatershaveaspecial1¾”
thread.Theyareratedat3kWat240VandareofalownoiseIncoloyconstruction.Theyhavebothathermostatandahigh
limitcutout.PleaseorderthecorrectreplacementfromBIASI;fittingnon‐approvedimmersionsmayaffectyourguarantee.
Whenfitting,ensurethe‘O’ringispositionedcorrectlyontheheadoftheimmersionheaterandlubricatebeforefitting.Fitit
byhanduntilalmosthomethentightengentlyasthe‘O’ringswillsealeasily.Theelectricalsupplytoeachimmersionheater
mustbefusedat13AviaadoublepoleisolatingswitchtoBS3456.Thecablemustbe2.5mm2heatresistant(85°CHOFR)
sheathedflexcomplyingtoBS6141:1981Table8.Donotoperatetheimmersionheater/suntiltheunitisfullofwater.Donot
operatetheimmersionheater/sifanysterilisationliquidisinthecylinderasthiswillcauseprematurefailure.Fittheimmersion
thermostat(indirectunitsonly)intothethermostatpocket.Completethewiring–usetheappropriatewiringdiagrams.


unventedhotwatercylinders
installationandmaintenanceinstructionsPage5/20

DISCHARGEARRANGEMENT
Note:Itisnotacceptabletodischargestraightintoasoilpipe

Note:Thedischargewillconsistofscaldingwaterandsteam.Asphalt,roofingfeltandnon‐metallicrainwatergoodsmaybedamagedbysuch
discharges.
Theinletcontrolgroupshouldbepositionedsothatthedischargefrombothsafetyvalvescanbecombinedviaa15mmend
feedTee,asinthediagramabove.
ConnectthetundishandroutethedischargepipewhichmustberoutedinaccordancewithBuildingregulation‐PartG3of
schedule1.
Whenoperatingnormallywaterwillnotbedischarged.Waterdischargefromthetwosafetyvalveswillonlyoccurunderfault
conditions.
Thetundishshouldbevertical,locatedinthesamespaceastheunventedhotwaterstoragesystemandbefittedascloseas
possible,within500mmofthesafetydevicee.g.thetemperaturereliefvalve.
Thepositionofthetundishmustbethatwheninstalleditisvisibletotheoccupantsofthepremises.
Whenpositioningthetundish,thedrainvalvesandmotorisedvalveensurethattheseitemsarepositionedawayfromany
electricaldevices.

Thedischargepipe(D2)comingfromthetundishshouldterminateinasafeplacewherethereisnorisktopersonsinthe
vicinityofthedischarge,beofmetaland:
A) Beatleastonepipesizelargerthanthenominaloutletsizeofthesafetydeviceunlessitstotalequivalenthydraulic
resistanceexceedsthatofastraightpipe9mlong,i.e.dischargepipesbetween9mand18mequivalentresistance
lengthshouldbeatleasttwosizeslargerthanthenominaloutletsizeofthesafetydevice,between18and27mat
least3sizeslarger,andsoon.Bendsmustbetakenintoaccountincalculatingtheflowresistance.Refertodiagram1,
Table1andtheworkedexample.AnalternativeapproachforsizingdischargepipeswouldbetofollowBS6700
Specificationfordesign,installation,testingandmaintenanceofservicessupplyingwaterfordomesticusewithin
buildingsandtheircurtilages.
B) Haveaverticalsectionofpipeatleast300mmlong,belowthetundishbeforeanyelbowsorbendsinthepipework.
C) Beinstalledwithacontinuousfall.
D) Itispreferableforthedischargetobevisibleatboththetundishandthefinalpointofdischarge.Wherethisisnot
possibleorpracticallydifficult,thereshouldbeclearvisibilityatoneorotheroftheselocations.


Examplesofacceptabledischargearrangementsare:
1.Ideallybelowthefixedgratingandabovethewatersealinatrappedgulley.
2.Downwarddischargesatalowlevel;i.e.upto100mmaboveexternalsurfacessuchascarparks,hardstandings,grassedareasetc.are
acceptableprovidingthatwherechildrenplayorotherwisecomeintocontactwithdischarges,awirecageorsimilarguardispositionedto
preventcontactwhilstmaintainingvisibility.
3.Dischargesatahighlevel;e.g.intometalhopperandmetaldownpipewiththeendofthedischargepipeclearlyvisible(tundishvisibleor


unventedhotwatercylinders
installationandmaintenanceinstructionsPage6/20

not)orontoaroofcapableofwithstandinghightemperaturedischargesofwaterand3mfromanyplasticgutteringsystemsthatwould
collectsuchdischarges(tundishavailable).
4.Whereasinglepipeservesanumberofdischarges,suchasinblocksofflats,thenumberservedshouldbelimitedtonotmorethan6
systemssothatanyinstallationcanbetracedreasonablyeasily.Thesinglecommondischargepipeshouldbeatleastonepipesizelargerthan
thelargestindividualdischargepipetobeconnected.Ifunventedhotwaterstoragesystemsareinstalledwheredischargesfromsafety
devicesmaynotbeapparent,i.e.indwellingsoccupiedbyblind,infirmordisabledpeople,considerationshouldbegiventotheinstallationof
anelectronicallyoperateddevicetowarnwhendischargetakesplace.

WORKEDEXAMPLE
TheexamplebelowisforG1/2temperaturereliefvalvewithadischargepipe(D2)having4No.elbowsandlengthof7mfromthetundishtothepointof
discharge.
FromTable1:
Maximumresistanceallowedforastraightlengthof22mmcopperdischargepipe(D2)fromaG1/2temperaturereliefvalveis:9.0m.Subtracttheresistancefor
4No.22mmelbowsat0.8meach=3.2m.Thereforethemaximumpermittedlengthequatesto:5.8m.5.8mislessthantheactuallengthof7m,therefore
calculatethenextlargestsize.
Maximumresistanceallowedforastraightlengthof28mmpipe(D2)fromaG1/2temperaturereliefvalveequatesto:14m.Astheactuallengthis7m,a28mm
(D2)copperpipewillbesatisfactory.

Table1‐Sizingofcopperdischargepipe(D2)foratemperaturereliefvalvewithaG1/2outletsize(assupplied).
Sizeofdischarge
pipework
Maximumlengthof
straightpipe(nobendsorelbows)
Deductthefigurebelowfromthemaximumlength
foreachbendorelbowinthedischargepipe
22mmUpto9m0.8m
28mmUpto18m1m
35mmUpto27m1.4m


unventedhotwatercylinders
installationandmaintenanceinstructionsPage7/20

TYPICALWIRINGDIAGRAMS
Thesediagramsrelateonlytothecomponentslisted.Othersmayvaryintheirwiringrequirements,particularlythermostats.
Alwaysrefertomanufacturers’instructionswhichmayoverridethedetailinordertofunctioncorrectly.
WIRINGDIAGRAM2xTWOPORTZONEVALVES(S‐
PLAN)VARIANTDUALTHERMOSTATWIRING
WIRINGDIAGRAMTHREEPORTMIDPOSITION
VALVE(Y‐PLAN)+TWOPORTVALVEVARIANT
DUALTHERMOSTATWIRING


COMMISSIONING
FILLING
Firstyoumustensurethatthepressureintheexpansionvesselisthesameasthesettingofthepressurereducingvalvei.e.3
bar(45PSI).ThevalveisoftheSchradercartyretype.Checkalltheconnectionsforwatertightnessincludinganyfactorymade
connectionssuchastheimmersionheaterandthetemperatureandpressurereliefvalve.Priortofilling,openthehottap
furthestawayfromtheBIASISILVERtoexpelair.Openthecoldmainisolationvalveandallowtheunittofill.
Oncethecylinderasbeenfullycommissionedshouldbeheatedtoitsnormaloperatingtemperature.Drawoffsecondaryhot
watertoeachoutletandallowhotwatertoflowfromeachoutletforatleast30secondstoremoveanyfluxresiduefromthe
pipeworkwithinthesecondaryhotwatersystem.Thenfullydrainthecylinderandre‐filledtoensurethatallfluxresiduesis
removedfromthesystem.

DIRECTUNITS
Afterbothfillingwithwaterandpurgingofsterilisationliquid,switchonthepowertotheimmersionheatersandallowtheunit
tostarttoheat.Theimmersionheaterissuppliedpresetat55°C.Turningfullyto+setstoapprox65°C.

INDIRECTUNITS
Filltheprimarycircuitaccordingtotheboilermanufacturers’commissioninginstructions.Ensuretheleveronthetwoportvalve
issettothefillingposition.Whenfull,movetheleverback.SwitchtheprogrammertoDomesticHotWater(DHW)andallow
theunittostarttoheat.Adjustthedialofthedualthermostattobetween30°Cand70°Casrequired.

STORAGETEMPERATURE
60‐65°Cistherecommendedstoragetemperatureforbothdirectandindirectcylinders.Inhardwaterareasconsideration
shouldbegiventoreducingthisto50‐55°C.InmanyhealthcareapplicationstheguidanceonLegionellacontrolandsafewater
deliverytemperatureswillrequirestoringthewaterat60‐65°C,distributingat50‐55°Candusingthermostaticmixingvalvesto
controlthefinaltemperature.FordetailsconsulttheNHSEstatesGuidanceonsafehotwatertemperatures.


GBrBlO 1 2 4 GBrBl O
HP22
Zone Valve (Htg) Room Stat
RMT 230 HP22
Zone Valve (Dhw)
1 2 345 6 78 9 10
43
LNE
Htg
on Dhw on LNE
LNE L
NE
1C
IDT
Dual Stat
Control
2C
Unit
High Limit
Stat
Power
Supply
E
N
L
12 212
Junction Box
1 2 3 2 3
2
3
FP75 or CP15 Programmer Basic Boiler Pump
C21 WGOBI
Cylinder Stat
ITD Dual Stat HP22
Mid Position Valve
1 2 3 4 5 6 7 8 9 10
43
LNE
Htg
on Dhw on LNE
LNE L
NE
C2
IDT Dual Stat
Power
Supply
E
N
L
23
Junction Box
1 2 3 2 3
2
3
FP75 or CP15 Programmer Basic Boiler Pump
124
Room Stat
RMT 230
2
G/Y
LN
NOT
USED 1
Dhw
off
BR BL G O
21
HP22
High Limit Stat


unventedhotwatercylinders
installationandmaintenanceinstructionsPage8/20

SAFETYVALVECHECKS
Anysignofwatercomingfromeithertheexpansionreliefvalveorthetemperature/pressurereliefvalveduringheat‐up
indicatesaproblem.Nextholdbothofthesesafetyvalvesfullyopen,allowingasmuchwateraspossibletoflowthroughthe
tundish.Checkthatyourdischargepipeworkisfreefromdebrisandiscarryingthewaterawaytowasteefficiently.Releasethe
valvesandcheckthattheyreseatproperly.
SERVICING
GENERAL
ServicingshouldonlybecarriedoutbycompetentinstallersandanysparepartsusedmustbepurchasedfromBIASICylinders.
NEVERbypassanysafetydevicesoroperatetheunitwithoutthembeingfullyoperational.

DRAINING
Switchtheelectricalpoweroff(importanttoavoiddamagetoelement).Isolateboilerfromtheunit.Turnoffthecoldwater
supplyvalve.Openhotwatertap.Openthedrainvalve.Theunitwilldrain.
WARNING:WATERDRAINEDOFFMAYBEVERYHOT!

ANNUALMAINTENANCE
Thewaterheatersrequireannualservicinginordertoensuresafeworkingandoptimumperformance.Itisessentialthatthe
followingchecksareperformedbyacompetentinstalleronanannualbasis.Thisiscommonlydoneatthesametimeasthe
annualboilerservice.
1)Twistthecapoftheexpansionreliefvalveontheinletcontrolsetandallowwatertoflowfor5seconds.Releaseand
makesureitresetscorrectly.Repeatwiththepressure/temperaturereliefvalve.Inbothcasescheckthatthe
dischargepipeworkiscarryingthewaterawayadequately.Ifnot,checkforblockagesetc.andclear.
WARNING:THEWATERDISCHARGEDMAYBEVERYHOT!
2)Checkthatanyimmersionheatersfittedareworkingcorrectlyandthattheyarecontrollingthewaterata
temperaturebetween55°Cand65°C.
3)Checkthepressureintheexpansionvesselischargedto3bar.Turnoffthewatersupplytotheunitandopenahot
tapfirst.TheairvalveonexpansionvesselisaSchrader(cartyre)type.AirorCO2maybeusedtochargetheexpansion
vessel.
4)Unscrewtheheadontheinletcontrolsetandcleanthemeshfilterwithin.
5)TheBenchmarkLogBooksuppliedwiththisunitshouldbeupdatedateachservice.

YOURGUARANTEEMAYBEVOIDWITHOUTPROOFOFANNUALSERVICING


SPAREPARTS
Afullrangeofsparepartsisavailable.



unventedhotwatercylinders
installationandmaintenanceinstructionsPage9/20

FAULTPOSSIBLECAUSESOLUTION
WaterescapingfromthecaseunitCompressionfittingonhot–drawoffnotsealingCheck/remakejointsealingpaste
Coldwaterathottaps
Direct–immersionheaternotswitchedonorcutout
hastriggeredCheck/reset
Indirect–boilernotworkingCheckboiler–consultboilermanufactures’
instructions
Indirect–motorizedvalvefaultCheckplumbing/wiringmotorizedvalve
Indirect–cutoutindualstathasoperatedResetandinvestigatecause
Waterdischargesfromexpansion
reliefvalve
Ifcontinual–pressurereducingvalve(partofinlet
controlset)maynotbeoperatingcorrectlyCheckoutletpressurefrominletcontrolsetis3bar
Ifcontinual–expansionreliefvalveseatmaybe
damagedRemovecartridge–checkseatandrenewifnecessary
Ifintermittent–expansionvesselchargemayhave
reduced/bladderperished
Checkpressureinexpansionvessel.Rechargeto3bar
ifnecessary.Ifbladderperishedreplacevessel
Unititbeingbackpressurized
Withcylindercoldcheckpressureincylinder.Ifthisis
thesameastheincomingmainspressurethenyouare
gettingbackfeed.Installabalancedcoldsupply
Waterdischargesfromtemperature
&pressurereliefvalveUnithasoverheated–thermalcontrolshavefailed
Switchedoffpowertoboilerandimmersionheaters.
Leavewatersupplyon.Waituntildischargesstops.
Isolatewatersupplyandreplaceiffaulty.
Milky/cloudywaterOxygenatedwaterWaterfromanypressurizedsystemwillreleaseoxygen
bubbleswhenflowing.Thebubbleswillsettleout.
Nohotwaterflow
ColdmainoffCheckandopenstopcock
StainerblockedinpressurereducingvalveIsolatewatersupplyandclean
InletcontrolsetmaybefittedincorrectlyCheckandrefitrequired
Noiseduringhotwaterdrawoff
–

typicallyworseinthemorningLooseairingcupboardpipeworkInstallextraclips
HotorwarmwaterfromcoldtapIftaprunscoldafteraminuteorsothepipeispicking
upheatfromheatingpipeworkInsulate/re‐route
GUARANTEE
ThestainlesssteelvesselcarriesafullyEXCLUSIONS–THEGUARANTEEDOESNOTCOVER:transferable25‐yearguarantee
againstfaultymaterialsormanufactureprovidedthat:
‐IthasbeencorrectlyinstalledaspertheInstallation.Instructionsandalltherelevantstandards,regulationsandcodes
ofpracticeinforceatthetime.
‐Ithasnotbeenmodifiedinanyway,otherthanbyBIASI.
‐Ithasnotbeenmisused,tamperedwithorsubjectedtoneglect.
‐Thesystemisfedfromthepublicmainswatersupply.
‐Ithasonlybeenusedforthestorageofpotablewater.
‐Ithasnotbeensubjectedtofrostdamage.
‐Theunithasbeenservicedannually.
‐TheBenchmarkLogBookhasbeenfilledinaftereachannualservice.
‐Theguaranteeperiodstartsfromthedateofpurchaseandnoregistrationisrequired.
Pleasenotethatinvoicesforservicingmayberequestedtoprovethattheunithasbeenservicedannually

TheexpansionvesselandcoldwatercontrolssuppliedwithBIASImodelscarrya2‐yearguarantee.Allothercomponentsfitted
to/orsuppliedwiththeunitcarrya2‐yearguarantee.





unventedhotwatercylinders
installationandmaintenanceinstructionsPage10/20

EXCLUSIONS–THEGUARANTEEDOESNOTCOVER:
‐Theeffectsofscalebuildup.
‐Anylabourchargesassociatedwithreplacingtheunitoritsparts.
‐Anyconsequentiallossescausedbythefailureormalfunctionoftheunit.

GUIDANCEINTHEEVENTOFAPROBLEM
Ifyouhaveaprobleminthefirstyear,contacttheplumberwhofittedtheunit.Thereaftercontacttheplumberwhocarriesout
theannualservicingforyou.IfyourBIASISilverdevelopsaleakwewillsupplyyouwithanewone.Weaskforanominalupfront
paymenttopreventfraud.Wewillrequiretheoriginalunittobereturnedtousforinspectionalongwithacopyofyour
BenchmarkLogBook.Ifitisconfirmedthatithasfailedwithinthetermsoftheguaranteeyourupfrontpaymentwillbe
refunded.
Ifacomponentpartfailswithintheguaranteeperiod,wewillsendyouanewonewithoutanyupfrontcharge.Creditcard
detailsmaybetakentopreventfraud.Weaskyoutopostthefaultypartbacktouswithinonemonthbyrecordeddelivery.
Ifyoudonotreturnthepartwewillchargeyouforitandforthepostageandpacking.Ifyourpartfailsaftertheguarantee
period,wewillaskforupfrontpayment.
USERINSTRUCTIONS
Yourstainlesssystemisautomaticinnormaluseandrequiresonlyannualservicing.Youshouldemployacompetentinstallerto
performtheannualservicing.Normallythisistimedtocoincidewiththeannualboilerservice.

IFWATERISFLOWINGFROMTHESAFETYVALVESTHROUGHTHETUNDISHTHISINDICATESAFAULTCONDITION
ANDACTIONISNEEDED.

Ifthiswaterishot,turntheboilerand/ortheimmersionheateroff.Donotturnoffthewateruntilthedischargerunscool.The
dischargemayalsostop.
CALLOUTACOMPETENTPLUMBERTOSERVICETHEUNIT.
Tellthemyouhaveafaultonanunventedcylinder.Westockallthesparepartstheymayneed.



unventedhotwatercylinders
installationandmaintenanceinstructionsPage11/20

TECHNICALSPECIFICATIONS
DIRECT
Topview
CAPACITY
[L]
A
[mm]
B
[mm]
C
[mm]
D
[mm]
E
[mm]
F
[mm]
WEIGHT
Empty[kg]
WEIGHT
Full[kg]
1251045812647287272‐ 30155
1501205972757287272‐ 34184
17013251092837287272‐ 37207
20015051272957287272104241241
250182515921167287272142749299
300210518721242287272166756356
INDIRECT
Topview
CAPACITY
[L]
A
[mm]
B
[mm]
C
[mm]
D
[mm]
E
[mm]
F
[mm]
G
[mm]
H
[mm]
I
[mm]
WEIGHT
Empty[kg]
WEIGHT
Full[kg]
1251045812‐340272290420615‐ 35158
1501205972‐340272290420615‐ 39187
17013251092‐ 327272290490690‐ 43210
20015051272957327272290490690104247244
250182515921167350272290525760142757303
300210518721242350272290525760166764360

A
E
D
B
F
C
Ø540
35°
35°
45°
45°
A
E
D
B
F
H
G
I
C
Ø540
35°
35°
45°
45°


unventedhotwatercylinders
installationandmaintenanceinstructionsPage12/20

SOLARUNVENTEDDIRECTSINGLECOILCYLINDER
DetailfortheinstallationofaSolarUnventedDirectcylinderinanelectrichome.
GENERAL
Wheninstallingthisproductitisessentialtheoverallinstallationmeetsallcurrentlegislationincluding,inparticular,thehigh
limitisolationrequirementsofBuildingRegulationG3.Thisdocumentisdesignedtoassistinachievingthataim.
WATER
ThepotablewaterconnectionandtundishdischargeconnectionaretobeconnectedinexactlythemannerdescribedinPages3
to7ofthismanual.
IMMERSIONHEATERS
Thestandardissueimmersionheatersaredesignedfordomesticusagewherethelowerheaterisconnectedtoalowrateoff‐
peaktariffandtheupperheaterusedforoccasionaltop‐uppurposes.Heatersofthisnaturearenotdesignedtobe
permanentlylive.ForusageoutsideofdomesticparametersTitaniumimmersionelementsarerecommended.
SOLARCONNECTIONS
Theflowandreturnfromthesolarheatsourcearetobeconnectedtotheindirectcoil.Eitherprimarycoilconnection(A)may
beutilisedasthefloworreturn.Thesolarsensor,suppliedaspartofthesolarcontrols,insertsintoPocketBandisheldin‐situ
withtheblacksensorpocketretainingbungprovided.Itisnecessarytomountthesolarpumpinthereturnpipeworkwiththe
RWC/ORKLItwoportvalve(suppliedwiththecylinder)installedbetweenthecylinderandthepump.Thisvalveisofthe
poweredopen,sprungcloseddesignandiswiredthroughtheImitITL100highlimitstatwhichinsertsintoPocketF.Twowiring
optionsforhighlimitisolationareprovidedinFig.1andFig.2.ThesuperioroptionisFig.2whichdisconnectsthepump
movementaswellasprovidesvalveclosure(seepages13and14).
SOLARUNVENTEDINDIRECTTWINCOILCYLINDER
Witheitherformatitisessentialtheoverallinstallationmeetsallcurrentlegislationincluding,inparticular,thehighlimit
isolationrequirementsofBuildingRegulationG3.Thisdocumentisdesignedtoassistinachievingthisaim.
UPPERCOIL
Theuppercoilisconnectedtothefossilfuel(notsolidfossilfuele.g.woodburnerorcoal)boileraspertheinstructionsforthe
UnventedIndirectsinglecoilmodelwiththelimitTLSCcontrolandhighlimitthermostatinsertedintopocketI(lowerdiagram
page14).Thewiringrequirementsareasdepictedonpage13.
LOWERCOIL:SOLARINSTALLATION
Inasolarpoweredsystemthelowercoilisconnectedtothesolarheatsource.Eitherprimarycoilconnectionmaybeutilisedas
thefloworreturn.Thesolarcylindersensor,suppliedaspartofthesolarcontrols,insertsintopocketF(seepage14).Itis
necessarytomountthesolarpumpinthereturnpipeworkwiththeRWC/ORKLItwoportvalve(suppliedwiththecylinder)
installedbetweenthecylinderandthepump.Thisvalveisofthepoweredopen,sprungcloseddesignandiswiredthroughthe
ImitITL100highlimitstatwhichinsertsintopocketL(lowerdiagrampage14).Twowiringoptionsforhighlimitisolationare
providedinFig.1andFig.2page13.ThelmitITC100controlthermostatisnotrequiredinasolarinstallation.
LOWERCOIL:TWOBOILERINSTALLATION
Wherethelowercoilistobeusedwithafossilfuel(notsolidfossilfuele.g.woodburnerorcoal)boiler,thepipework
requirementsareasperthatofaIndirectsinglecoilcylinderdescribedearlierinthisbook.ElectricallytheImitITC100inserts
intoPocketF(seepage14)tocontroltheboilerinputandtheImitITL100limitstatintoPocketL(lowerdiagrampage14).The
RWC/ORKLItwoportvalvemaybeinstalledintoeitherthefloworreturnpipework.WiringoftheITC100andITL100areasper
thewiringdetailusingtheImitTLSConpage7.



unventedhotwatercylinders
installationandmaintenanceinstructionsPage13/20

TYPICALSCHEMATICWIRINGDIAGRAM:SOLARHIGHLIMIT
CONTROL
TheseschematicwiringdiagramsdepictanIMIThighlimitcontrolstatandtheconnectionsarenumberedaccordingly.Where
analternativeissuppliedconnectaspermanufacturers’instructions.



unventedhotwatercylinders
installationandmaintenanceinstructionsPage14/20

TECHNICALSPECIFICATIONS
SOLARDIRECT
Topview
CAPACITY
[L]
A
[mm]
B
[mm]
C
[mm]
D
[mm]
E
[mm]
F
[mm]
G
[mm]
H
[mm]
I
[mm]
J
[mm]
WEIGHT
Empty[kg]
WEIGHT
Full[kg]
200150512729573272722904906901042125447244
2501825159211673502722905257601427157457303
3002105187212423502722905257601667185464360
SOLARINDIRECT
Topview
CAPACITY
[L]
A
[mm]
B
[mm]
C
[mm]
D
[mm]
E
[mm]
F
[mm]
G
[mm]
H
[mm]
I
[mm]
J
[mm]
K
[mm]
L
[mm]
WEIGHT
Empty
[kg]
WEIGHT
Full
[kg]
200150512727402722904906907909551042 1115125451246
250182515928822722905257609321097 1427 1332157463306
300210518727402722905257601072 1237 1667 1472185470363
A
E
D
B
F
H
G
I
C
J
Ø 540
35°
35°
45°
45°
A
D
B
E
G
F
J
C
L
H
I
K
Ø 540
35°
35°
45°
45°


unventedhotwatercylinders
installationandmaintenanceinstructionsPage15/20

SOLARUNVENTEDCYLINDERS
SolarcylindershavebeendesignedspecificallywithSolarapplicationsinmind.Featuringapurposedesignedsolarcoil,which
allowsmaximumheattransferofsolarenergyintothestoredwater,thecylindersaresuitableforusewithawiderangeofsolar
systemsnowavailableintheUKandIrelandandareanefficientandenvironmentallyfriendlywayofprovidingDomesticHot
Water.Solarcylindersalsoofferthebenefitofmainspressurehotwater–powerfulshowersandfastfillingbaths.

Solarcylindersareavailableinarangeofsizesfrom200L,250Land300litresandinDirectorIndirectversions.Solarcylinders
aremanufacturedfromhighgradeDuplexstainlesssteel.
Solarcylindersaredesignedtoacceptheatinputfromarenewable/sustainable(i.e.Solar)heatsource.Wherethisinputdoes
notfullymeetthedesiredtemperatureaguaranteedquantityofwatercanbeheatedtoanacceptabletemperaturebythe
householderstraditionalheatsourceofgas,oilorelectricity.
TheDomesticHeatingComplianceGuidedocumentL1AandL1Bprovidesexcellentadviceinsizingbothcylinderdesignated
solarareasandheatexchangerstothesurfaceareaofthesolarcollectors.Usingthisguideareabletooffersizingadvicefor
specification.
WATERCAPACITIES(LITRES)
ModelCapacityReferenceLowercoil
surfacearea
LowerCoil
rating
Uppercoil
surfacearea
UpperCoil
rating HeatuptimeRe‐heattime
Indirect
Direct
125125DI‐ ‐ ‐ ‐ 62min48min
150150DI‐ ‐ ‐ ‐ 76min63min
170170DI‐ ‐ ‐ ‐ 96min75min
200200DI‐ ‐ ‐ ‐ 119min91min
250250DI‐ ‐ ‐ ‐ 140min118min
300300DI‐ ‐ ‐ ‐ 166min141min
Indirect
125125IN0,59m²16kW‐ ‐ 23min19min
150150IN0,59m²16kW‐ ‐ 28min25min
170170IN0,71m²19kW‐ ‐ 34min25min
200200IN0,71m²19kW‐ ‐ 41min32min
250250IN0,84m²23kW‐ ‐ 47min32min
300300IN0,84m²23kW‐ ‐ 52min37min
Solar
Direct
200200SD0,71m²19kW‐ ‐ 35min32min
250250SD0,84m²23kW‐ ‐ 39min32min
300300SD0,84m²23kW‐ ‐ 43min37min
Solar
Indirect
200200SI0,71m²19kW0,59m²16kW33min32min
250250SI0,84m²23kW0,71m²19kW35min32min
300300SI0,84m²23kW0,71m²19kW39min37min




unventedhotwatercylinders
installationandmaintenanceinstructionsPage16/20


SPECIFICATIONSUMMARY

MATERIALS
‐Innershell‐DuplexStainlessSteel
‐Coil‐StainlessSteelAISI316L
‐Bosses‐StainlessSteel
‐Everycylinderiswatertestedtoapressureof10bar.

INSULATION
‐Fireretardantpolyurethanefoam,nominalthickness45‐50mm.
‐ThefoamisCFC‐FreeandHCFC‐Free.
‐ThefoamhasanOzoneDepletionPotentialofZeroandaGlobalWarming

CASEWORK
‐Electrostaticallypaintedsteel

ANODE
‐Nonefitted/nonerequired

EXPANSIONVESSEL
‐
CONTROLSETTINGS
‐PressureReducingValve‐3Bar
‐ExpansionReliefValve‐6Bar
‐PressureandTemperatureReliefValve‐7Bar/90°C
‐HighLimitThermostatinDualThermostat
‐HighLimitThermostatinImmersionHeater
IMMERSIONHEATER
‐1¾”BSPParallelThreadedHead
‐LongLifeIncoloySheathedLowNoiseElement16”
‐LongLongLifeIncoloySheathedThermostatPocket
‐BrazedConstruction
‐CombinedThermostatandSafetyCutout
‐ElementRating3kWat240VA/C





















M
A

A
NUFACTUR
E
instal
E
D b
y
w
w
unve
n
lationand
m
w
w.videira.pt
n
tedhotw
a
m
aintenanc
e
a
tercylinder
s
e
instruction
s
s

s
Page
1
1
7/20







instal
unve
n
lationand
m
n
tedhotw
a
m
aintenanc
e
a
tercylinder
s
e
instruction
s
s

s
Page
1
1
8/20


unventedhotwatercylinders
installationandmaintenanceinstructionsPage19/20


NOTES























































BiasiUKLtd
CommercialRoad
LeamoreEnterprisePark
Walsall
WS27NQ

Telephonenumber:01922714600
Faxnumber:01922714626
Companywebsite:www.biasi.co.uk