ENERCORP Heatstar HS2000ID User manual

DIESEL SPACE HEATER-SERVICE MANUAL
1. CONTROLS AND COMPONENTS
2. FLAME CONTROL CYCLES
3. MAINTENANCE SCHEDULE
4. REPAIR PROCEDURES
1. FAN MOTOR ASSEMBLY
2. FUEL FILTER ASSEMBLY
3. FUEL PUMP ASSEMBLY
4. ELECTRIC PANEL ASSEMBLY
5. AIR PRESSURE SWITCH
6. COMBUSTION HEAD ASSEMBLY
7. COMBUSTION CHAMBER
5. TROUBLESHOOTING GUIDE
6. WIRING DIAGRAMS
7. TECHNICAL SHEETS
INDEX
HS2000ID, HS3000ID
HS3500DF, HS6000DF
L-S 102.00-BM
WARNING
The operations described in this booklet must be carried out by qualied and instructed personnel only.
Incorrect maintenance may result in improper operation and serious injury.
1
!

1 COMBUSTION CHAMBER
2 BURNER ASSEMBLY
3 NOZZLE
4 FUEL VALVE
5 DIESEL PUMP
6 MOTOR
7 FAN
8 FUEL FILTER
9 FUEL CIRCUIT
10 FUEL TANK
11 FUEL TANK PLUG
12 DRAIN PLUG
13 RESET BUTTON/LAMP OF
CONTROL FLAME
14 MAIN SWITCH
15 ROOM THERMOSTAT PLUG
16 CONTROL LAMP
17 POWER CORD
18 OVERHEAT THERMOSTAT
19 AIR PRESSURE SWITCH GAUGE
(LOW PRESSURE SIDE)
20 AIR PRESSURE SWITCH GAUGE
(HIGH PRESSURE SIDE)
21 FLAME DETECTOR (PHOTOCELL)
22 STACK
1. CONTROLS AND COMPONENTS
INDIRECT HEATER WITH STACK:HS2000ID & HS3000ID
DIRECT HEATER WITHOUT STACK:HS3500DF & HS6000DF
CONTROL PANEL
2
13
16
17
1514

3
CONTROL SYSTEM
The heater has all operational controls located in a watertight control panel mounted on the lateral side of the unit.
The control panel consists of:
 •a3-positionswitchforheatingfunction:normaloperation,stoporthermostatoperation
 •plugtoconnectaremoteroomthermostat
 •powercord
 •highvoltagetransformerthatgeneratesasparktoignitetheame
 •controlameboxtohandlestarting/runningcycle(seeparagraph2.).
 Thecontrolameboxisequippedwithareset
Thecontrolsystemutilizes:
 •asafetyshutoffswitchthatisanoverheatthermostatshuttingdowntheunitifthetemperatureofcombustion
 chamberandoutletairexceedthemaximumallowedlevel
 •anairpressureswitch,thatstopstheunitiftheairowisnotsufcientforcombustion
 •aamedetector,thatisaphotocellmonitoringconstantlytheamepresenceanditsintegrity
 •apairofignitionrodstocreatetheignitionspark
FUEL SYSTEM
Thefuelsystemconsistsof:
 •fueltank,thatissteel,corrosionproof
 Thefueltankhasadrainpluglocatedunderneathittoallowdischargeofresidualfuelbeforecleaning.
 •fuellter
 •fuelpump.Ascrewttedonthefuelpumpallowstheadjustmentoffuelpressuresetting
 •fuelON/OFFsolenoidvalve
   •duringnormaloperationthevalveisopenandthepressurizedfuelowstothenozzlewhereitis
   atomized,mixedwithprimarycombustionairandignitedbytheelectrodespark
   •duringabnormaloperation(seeparagraph2.)theamecontrolunitclosesthefuelsolenoidvalveand
the unit stops.
 •fuelcircuit,includingsuctionandreturnhosesfromfueltanktofuelpumpandhighpressuremicrohosefromfuel
pumptonozzle
 •burnerhead
 •nozzle
COMBUSTION CHAMBER
For indirect heater it consists of:
 •theinternalcombustionchamber(stainlesssteel)thatcontainingtheamesand
 •theexternalhighefcientheatexchanger(aluminatedsteel),thatleadssmoketochimney/stack.
Fordirectheateritconsistsoftheinternalcombustionchamber(stainlesssteel),thatcontainingtheamesand
exchangesheatwiththemainairowstream.
BURNER HEAD
Theburnerheadistheassemblythatdeterminesthecorrectmixingofcombustionairandfuelinsidethecombustion
chamberanditconsistsof:
 •Fuelnozzle
 •Nozzlesupport
 •Flamediffuser
 •Airopeningbafe:ascrewttedontheburnerheadallowstheadjustmentofcombustionairsetting
 •Ignitionelectrodes
 •Flamedetector
FAN - MOTOR ASSEMBLY
Theelectricmotordrivesthefuelpumpassemblyandafanwhichblowsairinsideandaroundcombustionchamber.

4
2. FLAME CONTROL RUNNING / FAILURE CYCLE
Theamecontrolunitstartsthesequenceofoperationafteraheatingrequest(normaloperationorthermostatoperation)
and it consists of the following steps:
•Self-test(lessthan3s):self-checkofelectronicsefciency;
•PurgingtimeTP(20seconds):fanmotorandignitiontransformeraresimultaneouslyswitchedonwhilethefuelvalve
remainsclosedtoeliminateanyfuelorunburntresidual.
Duringthepurgingstage,theamesignalisconstantlymonitoredforanykindoffailureleadingtocombustionprevents
theburnerignition.
Incaseofheatingrequestoff(roomthermostatoff),thecontrolunitgoestostand-byposition.Thedeviceremainsin
thisstatustillclosingoftheroomthermostat;
•Safetytime(5seconds):attheendofthepurgingtimeTP,thefuelvalveisswitchedonandopensthefueltothe
nozzle.
IncaseofamedetectionfailurebytheendoftheTSsafetytime,thecontrolunitgoestolockout,andthefanmotor,
theignitiontransformerandthefuelvalvearede-energized,whilethelockoutsignalisenabled.
Otherwise,attheendoftheTSsafetytimethecontrolunitdisablestheignitiontransformerandgoestorunning
position.
•AttheendoftheTSsafetytimethecontrolunitkeepstheignitiontransformeroperatingforabout30s.
2.1 STARTING CYCLE
2.2 SHUT OFF CYCLE
Whentheheatingrequest(normaloperationorthermostatoff)opens:
•fuelvalveandignitiontransformerareswitchedoffandtheamelightsoff;
•burnerfanoperatesa90spost-purgeventilation
Restoringtheheatingrequestcausesthepost-purgetobeinterruptedandthestartingcycletobeperformed.
Room thermostat
Reset Lamp
Photocell
Fuel Valve
Ignition Transformer
Burner Fan
90 s
Room thermostat
Reset Lamp
Photocell
Fuel Valve
Ignition Transformer
Burner Fan
TP 20 s TS 5 s
30 s

5
2.3 FLAME FAILURE DURING STARTING CYCLE
IfduringthesafetytimeTS,thephotocellmonitorsaamefailure(signaltophotocellbecomeslowerthanminimum),at
theendofsafetytimetheunitgoesinlockoutcondition:
•burnerfan,ignitiontransformerandfuelvalvearede-energized;
•alarmlamponrestbuttonbecomesred
Unitcanre-startonlyifpressingtheresetbutton
2.4 EXTRANEOUS LIGHT OR FLAME DURING PRE-PURGE TIME TP
Ifduringthepre-purgetimethephotocellmonitorsanyresidualamethentheunitgoesinstand-bycondition:
•burnerfangoesontopurgingcombustionchamber
•fuelvalveandignitiontransformerarede-energized
•resetlampisoff;
Room thermostat
Reset Lamp
Photocell
Fuel Valve
Ignition Transformer
Burner Fan
TP 20 s
Room thermostat
Reset Lamp
Photocell
Fuel Valve
Ignition Transformer
Burner Fan
TP 20 s TS 5 s

6
2.5 FLAME FAILURE DURING RUNNING STATUS (ONE TRIAL RECYCLING)
Incaseofamefailureinrunningstatus,theamecontrolunitmakeonetrialrestartingtheunit.
Ifthereasonofamefailureisconrmed,thentheunitstopsinlock-outmode,andtheresetlampbecomesred.
2.6 RESET LAMP COLOR
WARNING
Theresetbuttonmayhavedifferentcolours:
•  lightoff:unitisinstand-bystatus,waitingforheatingrequest.
•  steadyorangelight:functionnotactive
•  steadygreenlight:unitisworkingnormally(startingcycleorworkingcycle)
•  steadyredlight:theheaterstopspermanentlyinlock-outstatusandcanrestartonlyifresetbuttonis 
pressed.
Room thermostat
Reset Lamp
Photocell
Fuel Valve
Ignition Transformer
Burner Fan
TP 20 s TS 5 s
90 s
!

7
3. MAINTENANCE SCHEDULE
Periodicmaintenanceoftheheaterisnecessarytoensureproperperformanceandtopreventfailuresanditshallbe
performedatthefollowingperiodicintervals:
• Daily maintenance
i.Inspectairinlet/airoutletandexhauststack,removedebrisifany
ii.Ifanyairhoseisinstalled,secureit.Minimizebendsandkeepsductsstraight
iii.Verifyfueltankisfull
iv.Verifythatexhauststackisproperlyinstalled
• Weekly maintenance
  i.Disassemble,inspectandcleanfuellterwithcleanfuel
  ii.Removetopcoverandcleanthemotor,fanbladeandtheinteriorshell
  iii.Inspectthefuelhoseassemblyandcheckforanyleaks
• 6 months maintenance
  i.Disassembleburnerhead
   1.Inspectandcleanburnerdiffuser
   2.Inspectandreplacenozzleasnecessary
   3.Cleanignitionelectrodesandadjustsettings
   4.Checkaircombustionsetting
  ii.Checkoverheatthermostat
  iii.Inspectandcleanthecombustionchamber
  iv.Openelectricboard,inspectelectricalcomponentsandcheckconnections
  v.Checkfuelpressuresettingoffuelpump
  vi.Inspectandtesttheburner

8
4. REPAIR PROCEDURES
WARNING
Before carrying out any maintenance operation the heater must be disconnected from power supply.
Refer to instruction manual to fully stop the heater. Therefore:
• Stop the machine as instructed
• Turn off the on/off switch on the main electric switchboard
• Wait until the heater has cooled.
Never service heater while it is plugged in, operating or hot.
Severe burns or electrical shock can occur.
1) FAN MOTOR ASSEMBLY
a) Tocleanthefanbladesandmotor,carryoutthefollowingprocedure.
 i)Removetheairinletgrille(a)byremovingfourscrewsthatsecureittothemachine.
 ii)Removethetopcoveraccesspanel(b)byremovingscrews
 iii)Inspectand,ifnecessary,cleanthemotorusingcompressedair,beingcarefullynottodirecttheairjettothe
  airpressureswitchgauge(c)(thepressureswitchcouldbedamaged)
iv)Cleanthefanbladesusingastiffbrush.
v)Reinstalltheinternalaccesspanel.
vi)Reinstallthefangrille.
!
c
b
a

9
b)Toreplacethefanbladeandtheelectricmotor,carryoutthefollowingprocedure.
 i)Removetheairinletgrille(a)byremovingfourscrewsthatsecureittothemachine.
 ii)Loosenthescrew(d)onthefanhub
iii)Extractthefanbladesandreplacewithanewonerespectingbladesorientation
iv)Removethetopcoveraccesspanel(b)byremovingfourscrews
v)Loosenthreeallenscrews(e)onthefuelpumpcasing(besurenottoremovethescrews)
vi)Removefuelpumpfromelectricmotorandkeepplasticcouplingfornextreassembly
vii)Loosenandremoveeightscrews(f)thatxthemotoronthemotorange
viii)Openmainelectricboardonside/frontoftheheater
ix)Tracetheelectricmotorpowercordsanddisconnectthethreewires(white,black,green)fromcontrolpanel
x)Positionanewmotoronthemotorangeandreassembleeightscrews(f)toxit
xi)Checkalignmentofthemotortotheheateraxisandtighteneightscrews(f)onmotorange
xii)Reassemblefuelpumponelectricmotorbeingsurethatplasticcouplingisaligned
xiii)Tightenthreeallenscrews(e)
xiv)Positionfanbladeonthemotorshaftbeingsurethereisnointerferencewithanypartswhenrotating
xv)Tightenscrew(d)andcheckfreerotationofthefanblades
xvi)Reinstallthefangrilleandthetopcover.
e
f
d

2) FUEL FILTER ASSEMBLY
a) Toclean/replacethepre-heatedtypefuellter,carryoutthefollowingprocedure.
 i)Removethescrew(a)thatsecuresthecovertothehousingandremoveo-ring(b)
10
ii)Usingasuitablecontainer,collectthefuelwhenremovingfromthefuellterassembly
iii)Removethefuelcell(c)andwashitwithcleandieseloil
iv)Ifnecessaryreplacethefuellter(c)
v)Ifnecessarytoreplacetheheatingelement,loosenthenut(d)andremovetheelectricelement(e)
vi)Inspecttheo-ring,replaceitifitiscracked,damaged,ordeformed
vii)Reassemblethelterassemblycheckingtheo-ringisplacedintherightposition
viii)Tightenscrew(a)
c
e
b
a

b)Toclean/replacethestandardtypefuellter,carryoutthefollowingprocedure.
i) Loosen the casing (a) that secures to the housing
11
ii)Usingasuitablecontainer,collectthefuelwhenremovingfromthefuellterassembly
iii)Removefuelcell(c)ando-ring(b)andwashwithcleandieseloil
iv)Ifnecessaryreplacethefuelcell(c)
v)Inspecttheo-ring,replaceitifitiscracked,damaged,ordeformed
vi)Reassemblethelterassemblycheckingtheo-ringisplacedintherightposition
vii)Tightencasing(a)byhand,checkingtheo-ringispressed
3) FUEL PUMP ASSEMBLY
a) Toreplacefuelpump,carryoutthefollowingprocedure.
i)Removethetopcoveraccesspanel(b)byremovingsixscrews
ii)Loosenthreescrews(e)onthefuelpumpcasing(besurenottoremovethescrews)
iii)Removefuelpumpfromelectricmotorandkeepplasticcouplingfornextreassembly
iv)Disconnectwiresleadtofuelsolenoidvalve(g)
v)Reassemblenewfuelpumponelectricmotorbeingsurethatplasticcouplingisaligned
vi)Tightenthreescrews(e)
vii)Reinstallthetopcover.
e
g
b
b
c
a

12
b)Tosetfuelpressureonfuelpump,carryoutthefollowingprocedure.
i)Removethetopcoveraccesspanel(b)byremovingscrews
ii) Loosen cap (a) on front of fuel pump and connect a fuel pressure meter
iii)Disconnectwiresleadingtofuelsolenoidvalve(toavoidfuelsprayinsidecombustionchamber)
WARNING
The following operation shall be done with top cover and possible access to rotating fan.
Fan rotating area is covered by fan support even if accessible
Take measure to avoid touching any rotating parts while setting fuel pressure
iv)Starttheheaterandcheckthefuelpressurevaluelistedinthenaltechnicalsheet
v)Correctthepressurebyscrewing(toincreasepressure)orunscrewing(todecreasepressure)screw(b)
vi)Removefuelpressuremeterandtightencap(a)
vii)Connectwirestosolenoidfuelvalve
viii)Reinstallthetopcover.
4) ELECTRIC PANEL ASSEMBLY
a) Tocheckelectriccontrolboard,carryoutthefollowingprocedure.
 i)Removetwoscrews(a)onfront/sideofheater
 ii)Removetopcover(b)ofelectricboard
!
b
a
a
b

13
5) AIR PRESSURE SWITCH
iii)Checkthatallconnectionsarecompleteandtight
iv)Reassembletopcover(b)andxelectricboardtotheheater
a) Tocheck/replaceairpressureswitch,carryoutthefollowingprocedure.
 i)Removefourscrews(a)onsideofheater
ii)Pullairpressureswitchassemblyoutofthebase
iii)Checksiliconetubearenotpinchedandtightenedtoconnectors
iv)Checkthereisnodebrisinsidesilicontube
v)Reassemblepressureswitchassemblyandtightenscrews(a)
6) COMBUSTION HEAD ASSEMBLY
a) Tocleancombustionheadassembly,carryoutthefollowingprocedure.
 i)Removethetopcoveraccesspanel(b)byremovingsixscrews
ii)Loosenscrew(a)andremovewireconnectorofyellow/greenwire)(c)
a
c
b
a

iii)Turncounterclockwiseburnersupport(d)andpullitoutofburnertube(e)
14
iv)Check/Cleandiffuserring(f)
 (1)besureanydebrisorsootiseliminatedoneverywingandopeningonfrontsurfaceofring
 (2)ifnecessaryloosenscrew(f)andremoveittowashusingcleandiesel
 (3)checkforanydamageorbendedpart:ifanyreplaceit
v)Check/cleanignitionelectrodes(g)
 (1)Cleanandremoveanydebrisorsootonsharpendsofelectrodes
 (2)Ifnecessaryremovebothelectrodesandreplace
 (3)Checkalignmentasbyfollowingimage:electrodesshallbecenteredandsymmetric
(4)Checkelectrodeconnectors(h)totightenandclean
e
f
e
d
g

vi)Check/replacefuelnozzle
 (1)Refertotechnicaldatasheetforspecicindicationofnozzletype
 (2)Removeelectrodes(g)
 (3)Removediffuserring(f)
 (4)Loosenfuelnozzleandreplacewithanewone
 (5)Reassemblediffuserringandelectrodestakingcareofeachcorrectpositioningasprevious 
instructions
vii)Check/cleanphotocell
 (1)Removephotocell(i)andcheckitisclean
 (2)Checkphotocellsupportbecleanandcleanhole(m)
15
viii)Check/adjustairopenings
(1) Loosen nut (n)
 (2)Adjustlever(p)untiltherequestedopeningisobtained(checknaltech.sheet)
i
h
m

16
ix)Reassemblecombustionhead
x)Reassembletopcover
7) COMBUSTION CHAMBER ASSEMBLY
a) Tocleancombustionchamberassembly,carryoutthefollowingprocedure.
 i)Removethetopcoveraccesspanel(b)byremovingsixscrews
ii)Loosenandremovethreenuts(a)
iii)Removetheburnerheadtubeassembly(c)
iv)Checkandcleaninsidecombustionchamberwithacloth,removingliquidfuelresidual
v)Reassembleburnerheadtubeassembly(c)
vi)Reassembletopcover(b)
b
p
n
a
c

17
5. TROUBLESHOOTING GUIDE
A. HEATER DOES NOT START
a. Main control lamp is off
  i.Missingconnectiontomainsupplyline
   1.Checkmainsupplyisswitchedon
   2.Checkconnectionofextensionpowercord
   3.Checkintegrityofmainfuse
b. Motor does not run and reset lamp is red
i.Flamecontrolboxinlockingconditionforapreviousproblem
   1.Resetandrepeatthestartingcycleonetimeonly.
   2.Refertofollowingifanynewproblemoccurs
c. Motor does not run and rest lamp lights up after 30 secs
i.Airowfailure
   1.Checkfanmotorconnections
   2.Checkfanistightenedonfanmotoraxle
   3.Checkfanisfreetorotate:ifnot,servicefuelpump
   4.Checkandeventuallyreplacefanmotorand/ormotorcapacitor.
d. Motor does not run and reset lamp is off (unit is in stand-by)
i. Room thermostat / main switch failure
   1.Checkroomthermostat
   2.Checkroomthermostatconnections
   3.Checkmainswitchonheatercontrolboard
ii. Photocell failure (short circuit)
1. Replace photocell
  iii.Flamecontrolboxfailure
   1.Checkfuseintegrityonamecontrolbox
   2.Checkwiringconnectionandeventuallyreplaceamecontrolbox
  iv.Voltagelowerthan70Vorhigherthan150V
   1.Checksupplyvoltageiscorrespondenttoratingplate.
   2.Unitwillautomaticallyrestartwhenvoltagebecomeshigherthan80Vorlowerthan140V
B. HEATER STARTS BUT DOES NOT COMPLETE STARTING CYCLE
a. Motor runs continuously, there are no ame and reset lamp is off
i.Extraneouslightorameduringpre-purgecycle
   1.Checkpositioningofphotocell
   2.Makeserviceofcombustionheadandcombustionchamberremovinganyresidualfuelinside
   3.Checkanysunlightorexternallightcanreachthephotocell
b. Heater stops in lock-out and reset lamp is on (red light)
i.Flamefailureduringstartingcyclebecauseofincorrectignition
   1.Checkconnectiontoignitionelectrode
   2.Check,cleanandadjustpositioningofignitionelectrode
   3.Checkignitiontransformerandeventuallyreplace
   4.Checkmainconnectionstoignitiontransformer
  ii.Flamefailureduringstartingcyclebecauseofmissing/incorrectame
   1.Checkfueltankisnotempty
   2.Checkfueltypebecorrectandclean
   3.Checkandcleanfuelltercartridge
   4.Checkallconnectionsoffuellinefromtanktofuelpump:untightenedconnectionscancause
suction of air to fuel pump
   5.Checkfuelline(fromto/thefueltankandtothenozzle)arenotobstructedordamagedand
   eventuallyreplace
   6.Checkandcleanfuelnozzle(eventuallyreplaceit)
   7.Checkandcleancombustionhead(nozzle,nozzlesupportanddiffuserdisc)
   8.Checkandeventuallyreplacesolenoidvalveonfuelpump
   9.Checkadjustmentoffuelpumppressure
  10.Checkadjustmentofcombustionair

18
C. HEATER STARTS BUT IT DOES NOT RUN REGULARLY
a. Heater stops in lock-out and reset lamp is on (red light)
i.Flamefailurebecauseofmissingfuel
   1.Checkfueltankisnotempty
   2.Checkfueltypebecorrect,cleanandwithoutwater
   3.Checkandcleanfuelltercartridge
   4.Checkallconnectionsoffuellinefromtanktofuelpump:untightenedconnectionscancause
suction of air to fuel pump
   5.Checkfuellinearenotobstructedordamagedandeventuallyreplace
   6.Checkadjustmentoffuelpumppressure
ii.Flamefailurebecauseofbadcombustion
   1.Checkandcleanfuelnozzle(eventuallyreplaceit)
   2.Checkandcleancombustionhead(nozzle,nozzlesupportanddiffuserdisc)
   3.Checkadjustmentoffuelpumppressure
   4.Checkadjustmentofcombustionair
  iii.FlamefailurebecauseofairpressureswitchPAnotworking.
   1.Checkfanistightenedonfanmotorshaft.
   2.Checkthereisnoobjectobstructingairinlet
   3.Checkhosetoairpressureswitcharenoobstructed
   4.Checkconnectionstoelectricalwiringsofairpressureswitch
   5.Checkandeventuallyreplaceairpressureswitch
  iv.FlamefailurebecauseofsafetythermostatLIcuttingin
   1.Checkthereisnoobjectobstructingairoutlet
   2.Checkairoutlethoserespectmaximumlengthanddiameterasspecied
   3.Checkconnectionstoelectricalwiringsofoverheatingthermostat
   4.Checkandeventuallyreplacesafetythermostat
b. Heater stops in stand-by and reset lamp is off
i. Voltage lower than 70 V or higher than 150 V
   1.Checksupplyvoltageiscorrespondenttoratingplate.
   2.Unitwillautomaticallyrestartwhenvoltagebecomeshigherthan80Vorlowerthan140V.
c. Heater starts and stops ames and main fan remains on (unit is in stand-by and rest lamp is off)
  i.Airbubblesinthesuctionlinetofuelpump
   1.Checkoilltercasingistightened
   2.Checkallconnectiononfuellinetofuelpumparetightened
   3.Checkfuellinearenotobstructed
   4.Checkfueltanklevel
D. HEATER RUNS WITH BAD COMBUSTION AND EVENTUALLY WITH WHITE OR BLACK SMOKES
a. Heater runs with white smokes
i.Fuel/airmixingoncombustionheadisincorrect:excessairorlittlefuel
   1.Checkadjustmentoffuelpumppressure
   2.Checkadjustmentofcombustionair
b. Heater runs with black smokes
i.Fuel/airmixingoncombustionheadisincorrect:littleairorexcessfuel
   1.Checkadjustmentoffuelpumppressure
   2.Checkadjustmentofcombustionair
c. Heater runs with noisy / irregular combustion with/without smokes
i.Combustionisincorrect
   1.Checkandcleanfuelnozzle(eventuallyreplaceit)
   2.Checkandcleancombustionhead(nozzle,nozzlesupportanddiffuserdisc)
   3.Checkexhaustisnotobstructed
   4.Checkcombustionchamberisnotcloggedbysootandeventuallywashandcleanit

E. WHEN HEATER IS SWITCHED OFF, IT DOES NOT STOP
a. Heater still runs with ame
i. Room thermostat / main switch failure
   1.Checkroomthermostatandroomthermostatconnections
   2.Checkmainswitchonheatercontrolboard
  ii.Fuelowtonozzleisnotinterrupted
   1.Checkfuelsolenoidvalveclosefuellinetonozzle
19

20
6. WIRING DIAGRAM
NOTE
AirpressureswitchPAandoverheatingthermostatLI1areconnectedinserietofuelvalveEV1.
ThereforeincasePAandLI1opens,thefuelvalveEV1isswitchedoffandtheamecontrolunitgoesinlock-outin
the“amefailuremode”.
FU Fuse 20 A
IT H.T. Transformer
LI1 Overheatthermostat
EV1 Fuelsolenoidvalve
FO Photocell
CO Capacitor
MV Fan motor
ST Control lamp
RV Main switch
TA Room thermostat plug
AP Flamecontrolbox
RF Heatedfuellter(optional)
PA Air pressure switch
FUA Fuse6,3A
RE RELAY
FU FUSE 20 A
HS2000ID, HS3000ID, HS3500DF