Elson 150zd - Fault Finding and Servicing; Fault Finding Chart Usage; Control Tampering Warning

17
IMPORTANT
Afterservicing,completetherelevantService•
IntervalRecordsectionoftheBenchmark
Checklistlocatedonpage22and23ofthis
document.
Servicingshouldonlybecarriedoutby•
competent persons in the installation and
maintenanceofunventedwaterheating
systems.
AnysparepartsusedMUSTbeauthorised•
parts.
Disconnecttheelectricalsupplybeforeremoving•
anyelectricalequipmentcovers.
NEVERbypassanythermalcontrolsoroperate•
systemwithoutthenecessarysafetyvalves.
Watercontainedinthecylindermaybevery•
hot,especiallyfollowingathermalcontrolfailure.
Cautionmustbetakenwhendrawingwaterfrom
theunit.
SPAREPARTS
Afullrangeofsparepartsareavailableforthe
cylinderrange(Table5Page18).Refertothe
technicaldatalabelontheunittoidentifythemodel
installedandensurethecorrectpartisordered.You
willneedtoquotetheserialnumber,whichisprinted
onthedatalabel.
FAULT FINDING
Thefaultndingchart(Table4Page17)willenable
operational faults to be identied and their possible
causesrectied.Anyworkcarriedoutonthecylinder
unvented water heater and its associated controls
MUST be carried out by a competent installer for
unvented water heating systems. In case of doubt
contact servicesupport(seecontactdetailsonback
page).
WARNING
DO NOT TAMPER WITH ANY OF THE SAFETY VALVES
OR CONTROLS SUPPLIED WITH THE CYLINDER AS
THIS WILL INVALIDATE ANY GUARANTEE.
FAULT FINDING & SERVICING
Table4:FaultFindingChart
Fault Possible Cause Remedy
Nohotwaterow
Mainssupplyoff Checkandopenstopcock
Strainerblocked Turnoffwatersupply.Removestrainerand
clean
Coldwatercombinationvalveincorrectly
tted
Checkandretasrequired
Waterfromhottap
is cold
Direct immersion heater not switched on Checkandswitchon
Directimmersionheaterthermalcut-out
has operated
Check,resetbypushingbuttononthermostat
Indirect programmer set to central heat-
ing only
Check,settodomestichotwaterprogramme
Indirectboilernotworking Checkboileroperation.Iffaultissuspected
consultboilermanufacturer’sinstructions
Indirectthermalcut-outhasoperated Check,resetbypushingbuttononthermostat
Checkoperationofindirectthermostat
Indirect motorised valve not connected
correctly
Checkwiringand/orplumbingconnectionsto
motorised valve
Waterdischarges
fromexpansion
valve
INTERMITTENTLY
Expansion vessel charge pressure has
reducedbelow3.5bar,orsettohigh
SeeMaintenancesectionforre-chargingof
expansion vessel procedure
CONTINUALLY
coldwatercombinationvalvepressure
reducernotworkingcorrectly.
Expansion valve seat damaged
Checkpressurefromcoldwatercombination
valve.Ifgreaterthan3.5barreplacepressure
reducing valve
Removeexpansionvalvecartridge,check
conditionofseat.Ifnecessarytnewexpansion
valve
Waterdischarges
fromT&Prelief
valve
Thermalcontrolfailure
NOTE: water will be very hot
Switchoffpowertoimmersionheater(s)and
shutdownboiler.
DO NOTturnoffwatersupply.Whendischarge
stopscheckallthermalcontrols,replaceiffaulty
Milkywater
Oxygenated water Waterfromapressurisedsystemreleases
oxygenbubbleswhenowing.Themilkinesswill
disappearafterashortwhile