Market Forge Industries M24SC User manual

An Employee Owned Company Form No. S-5046C ●05/10
35 Garvey Street ●Everett ●MA ●02149-4403
Tel: [phone] ●Fax: [phone]
custserv@mi.com ●www.mi.com
OWNER’S MANUAL
MODULAR STEAM COIL BOILER
MODELS:
  ●M24SC
  ●M36SC

TABLE OF CONTENTS
i
INTRODUCTION............................................................................................................... 1
OPERATION........................................................................................................ 1
INSTALLATION
RECEIVING INSTRUCTIONS ............................................................................. 1
SETTING IN PLACE............................................................................................ 1
INSTALLING LEGS.................................................................................. 1
LEVELING ............................................................................................... 1
PANELS AND DOORS ............................................................................ 1
IMPORTANT INFORMATION ON STEAM COIL STEAM GENERATORS TO
STEAM FITTER .................................................................................................. 1
SERVICE CONNECTIONS.................................................................................. 2
BOILER HORSEPOWER AND STEAM FLOW INFORMATION ......................... 3
STEAM FITTER AND PLUMBER ........................................................................ 4
STEAM CONNECTION ........................................................................... 4
SETTING OF STEAM GENERATOR PRESSURE CONTROL SWITCHES
(ON MODELS BEFORE 1979) ............................................................................ 4
PRESSURE CONTROL SWITCH ADJUSTMENT (ON MODES AFTER 1979).. 6
WATER LEVEL CONTROL (ON MODELS BEFORE 1984) ................................ 6
DISASSEMBLY INSTRUCTIONS........................................................................ 6
WATER LEVEL CONTROL (ON MODELS AFTER 1984) .................................. 7
TO REMOVE WATER LEVEL CONTROL ........................................................... 7
WATTS PRESSURE REDUCING VALVE - 3/4” .................................................. 7
OPERATION OF WATTS PRESSURE REDUCING VALVE - 3/4” .......... 7
ADJUSTING WATTS PRESSURE REDUCING VALVE - 3/4” ................. 7
WIRING DIAGRAMS ........................................................................................... 8-14
OPERATION
START UP............................................................................................................ 15
AUTOMATIC DRAIN............................................................................................ 15
DAILY OPERATING INSTRUCTIONS................................................................. 15
UNITS MANUFACTURED AFTER 1983, EQUIPPED WITH “MOMENTARY”
HEAT SWITCH .................................................................................................... 15
DAILY OPERATING INSTRUCTIONS ..................................................... 15
DAILY SHUT DOWN FOR UNITS MANUFACTURED AFTER 1983....... 15
MANUAL DRAIN STEAM GENERATOR FOR UNITS
MANUFACTURED AFTER 1983 ............................................................. 15
TROUBLE-SHOOTING
TRIOUBLE-SHOOTING GUIDE .......................................................................... 16
ILLUSTRATED PARTS
WATER LEVEL AND STEAM CONTROL............................................................ 18
PLUMBING .......................................................................................................... 19
CONTROL BOX................................................................................................... 20
24” CABINET ....................................................................................................... 21
36” CABINET ....................................................................................................... 22

INTRODUCTION
1
Polishedstainlesssteelcabinetbaseshallbeofmodular
designtomatchotherMarketForgecookingequipment,
andequippedwith6”152mmstainlesssteellegs,adjust-
ablebulletfeet,reinforcedstainlesssteelcounter-topand
stainlesssteellift-offfrontpanel.
Stainlesssteelsteamcoilgeneratorequippedforopera-
tionat15PSI(1kg/cm2).Unitshallincludeasstandardan
automaticdrain,coldwatercondenser,automaticwater
levelcontrol,lowwatercutoff,pressurecontrol,airvent,
andasafetyreliefvalve.
Steam generator shall be National Board Registered,
andshallbesuitableforinstallationtightagainstanon-
combustablewall.SteamgeneratorshallbeASMEcon-
structedof15PSIoperation.
Steam generator shall be automatically lled with cold
water and brought to pressure when heat and water
switches are turned on and automatically drain under
pressureshallautomaticallycondenseexhaustedsteam
intowaterbeforereleasingittodrain.
OPERATION:
Unitequippedforoperationwithminimumincomingpres-
sure of 20 PSI (1.4kg/cm2) and a maximum incoming
pressure of 50 PSI (3.5kg/cm2), producing a minimum
outputof2.6BHPand88poundsofsteamperhour.
INSTALLATION
WARNING: Read before opening the shipping contain-
ers. Do not at any time lay the equipment down on its
back,side,toporfront.Todosomaydamagetheequip-
mentandinvalidatethewarranty.
RECEIVING INSTRUCTIONS:
Inspect the equipment before signing the bill of lading.
The equipment supplied was tested and inspected be-
foreshipment.Thecarrieracceptedit ascompleteand
withoutdamage.
Thismerchandisebecameyourpropertywhenitwasac-
ceptedbythecarrieratthefactory.MarketForgecannot
assumeresponsibilityforlossordamageduringtransit.
Forthisreason,youshouldimmediatelyinspectforvis-
ibleandconcealeddamageorshortagesbeforesigning
forshipmentasfollows:
Countthenumberofcartonsandpackagesreceived
tobesuretheycoincidewiththebilloflading.
Visuallycheckallcartonsforexternaldamage.
Removeallcartonsfromtheirskidstoexamineequip-
mentforconcealeddamage.Thecartonisnailedand
strappedtotheskid. It willbenecessarytocut the
strapsandpryoffthecontainer.
Afterinspection,replacethecartonsovertheequip-
mentontheskids toprotectandsecurethe equip-
mentuntilitisreadyforinstallation.
Sign for shipment if all is in order. Note shortages,
externalandconcealeddamage,ifany,onthebillof
lading before accepting a partial or damaged ship-
ment.
Ifnecessary,contactthecarrierimmediatelytolea
claim.Allclaimsmustbeledbythereceiver.
1.
2.
3.
4.
5.
6.
Do not remove the cartons or the skids from the
cookingequipmentuntiltheunithasbeentransport-
edthroughthebuildingtotheactualset-uplocation.
Thecartonsshouldremain.ontheequipmentaspro-
tectionagainstdentsandscratches.
SETTING IN PLACE:
Installing legs:
Somemodelsareshippedwithoutlegs.Aseparatecar-
ton will contain the legs. If your model is received this
way be sure to follow the installation instruction sheet
packedwiththelegs.
Leveling:
Inorderfortheboilertodraincorrectlyitisimportantto
usealeveloncabinettop,bothleftandrightandfront-
to-back.Ifnotleveladjustfeet.Oncompartmentcookers
checkinteriorshelvestobelevel.
Panels and Doors:
Panelsanddoorsforthecabinetmaybeshippedsepa-
rate.Refertoinstallationinstructionsenclosedwithpan-
elsanddoorsformethodofattaching.Itisrecommended
thatpanelsanddoorsbeinstalledaftermechanicalcon-
nectionsaremadetoavoiddamage.
IMPORTANT INFORMATION ON STEAM COIL STEAM
GENERATORS TO STEAM FITTER:
The-useofsteamcoiloperatedequipmentisincreasing,
anditisimportantthatyouareawareofboththeadvan-
tagesandthelimitationsofthisequipment.
Asteamcoilgeneratorassuresasupplyofcleansteam,
andisgenerallyrecommendedwhensteamisavailable
7.

INSTALLATION
2

INSTALLATION
3
butnot,consideredcleanenoughtocomeincontactwith
food.Toxicsteamgeneratorcleaningcompoundsareof-
tenusedtocleansteamgenerators,andthisisusually
thereasonfornotrecommendingdirectconnectedcook-
ers.
Itisveryimportantthataminimumof15PSIbeavailable
intheincomingsteamlineifasteamcoilsteamgenerator
istobeinstalledforusewitha5PSIcompartmentcooker.
Iftheequipmentconnectedtothesteamgeneratoroper-
atesat15PSI,minimumincomingpressuremustbe30
PSI,exceptinthecaseofasingleSteam-It,whichcanbe
operatedonanincomingpressureof20PSI.Maximum
recommendedincomingsteampressureis50PSI.(the
table below)showsBoilerHorsePower(BHP)generated
byoursteamcoilboilersatvariousincomingpressures.
One(1)BHPisrequiredforeachcookingcompartment
in“A”and“W”models.Ajetcookerrequires3BHPand
aSteam-It112BHP.Itisnotnecessarytoincludesteam
requirements for kettles, as kettles may be direct con-
nectedsincethesteamdoesnotcomeintocontactwith
thefood.
TABLE 1:
Pressure
maintained on
incoming Steam
line
BHP OUTPUT
Steam generator
set at 15 PSI
Steam generator
set at 5 PSI
15 PSI -- 3.5
20 PSI 8 4.0
30 PSI 3.4 (Max. BHP available
regardless of incom-
ing pressure)
35 PSI 4.0
Pleasenotethatasteamcoilboilersetat5PSIwillgen-
erate more boiler horsepower then one set at 15 PSI.
Thisisbecausethe greatertemperaturedifferentialbe-
tweenthesteamontheincominglineandthesteamgen-
eratedinthesteamgenerator,thegreatertheBHPavail-
able.Forpropercookingresultsyoumusthavesufcient
steam ow. Both pressure and volume are important.
Thisrelatestopipesizeandsteamsupplytothesteam
coilsteamgenerator.
BOILER HORSEPOWER & STEAM FLOW
INFORMATION:
Recommended boiler horsepower and steam ow in
poundsperhour(Note: one boiler horsepower 34.5 lbs.
of steam per hour. Do not confuse steam pressure with
steam ow).
TABLE 2:
Delivered
Boiler
H.P.
Steam
FlowLbs.
Steam Per
Hour
CompartmentSteamCookers
(per compartment)
1 34.5
SteamJacketedKettles(Per 20 gallons) 1 34.5
DirectConnectSteam-It 1/2 17.25
TABLE 3:
Followofsteaminpipe,inpoundsofsteamperinch.
Line pressure
in lbs. per
square inch
(PSI)
Pipe Size in inches
1/2 3/4 1 1 1/4 1 1/2 2
5 60 110 200 390 550 970
10 70 125 220 430 610 1075
15 75 135 240 470 665 1170
20 80 145 255 505 715 1255
25 85 155 270 530 740 1300
30 90 165 285 565 800 1400
40 100 185 320 615 885 1550
50 108 200 345 680 965 1680
60 114 214 368 730 1030 1800
70 120 226 390 770 1095 1910
Capacities are based on allowing a pressure drop of 2
PSIinalengthofpipeequalto240diametersofpipe.For
example(Figure 1)in one-inchpipeatthe steamows
shown,therewouldbeapressuredropof2PSIin240
inches,(20 Feet)ofstraightrun.
Figure 1
If the rate of ow is increased, the pressure drop will
begreater.Iftherateofowisdecreasedthepressure
dropwillbeless.Elbows,valvesandotherttingscause
greaterpressuredrop.Indeterminingproperpipesizeat
agivenlinepressuretodeliverthedesiredrateofsteam
ow and pressure at the steam cooker, it is necessary
toknownotonlythe actuallengthof piperun,butalso
theequivalentlengthofrun.Eachttingorvaluecauses
resistanceequaltoacertainlengthofstraightpipe.This
equivalentlengthmustbeaddedtotheactuallengthof
20 feet of 20 inches of pipe with two elbows, an angle
valveandsideoutlettee.Table5onpage4showsthatto
determinetheequivalentlengthofrunwemustadd2.2
feetforeachofthe elbows, 12 feetfortheanglevalve
and5feetforthesideoutlettee,givingusanequivalent

INSTALLATION
4
lengthofrunof41.4feetofstraightpipe.
Figure 2
Actualrun20feet.Equivalentrun41.4feet.Rateofow
240poundsofsteamperhour.
TABLE 4: Resistance of ttings expressed in terms of
equivalentlengthofstraightpipe.(Measurements are in
feet)
Pipe
Size
Standard
Elbow
Side
Outlet
Tee
Gate
Valve
Globe
Valve
Angle
Valve
1/2” 1.3’ 3’ 0.3’ 14’ 7’
3/4” 1.8’ 4’ 0.4’ 18’ 10’
1” 2.2’ 5’ 0.5’ 23’ 12’
11/4” 3.0’ 6’ 0.6’ 29’ 15’
11/2” 3.5’ 7’ 0.8’ 34’ 18’
2” 4.3’ 8’ 1’ 46’ 22’
TABLE 5:Temperature(OF)ofsteamatvariousaltitudes
andpressures.
Altitude 5 PSI 10 PSI 15 PSI
Sea Level 227 240 250
2,000feet 224 237 248
5,000feet 220 234 245
10,000feet 213 228 240
Rule-of-thumbConversionInformation
1BHP-approximately10kW.
1BHP-approximately34,000BTU
These conversions are easily remembered approxima-
tions. in make conversions, the efciency of the steam
generator must be considered.A gas steam generator
with an in put of 34,000 BTu and operating at 50% ef-
ciencywilldeliver1/2BHP.
STEAM FITTER & PLUMBER:
Steam Connection:
Itisrecommendedthatwheneverpossiblethesteamin-
puttothesteamgenerator be a separatelinefromthe
sourceofsupply.Ifthesteamgenerator mustbepiped
toalinewhichalsosuppliesothersteamconsumingde-
vicesthepipesizeandpressurewillhavetobeveried
astocapacity.
SUGGESTED STEAM CONNECTIONS:
Figure 3
ITEM DESCRIPTION PART #
1  3/4”GlobeValve 10-2821
2  BallFloatTrap  10-5336
3  PressureGauge ----------
Figure 3 shows a recommended system of the instal-
lation which includes the following equipment.:A globe
valve,forshutoff,aballoattrapwhichassuresthatthe
steamsupplyiscleananddry,andapressuregaugeto
measureinletpressurefromthesourceofsupply.Note: If
steam supply line has an extremely high excess amount
of condensate, it may be necessary to install two ball oat
traps.
IMPORTANT:Beforemakingnalconnection,blowout
thesteamlinetoremovealldirt,scale,packing,etc.,that
maybeaccumulatedduringpipettings.
Ifcondensatecomingoutofthecoilistobereturnedto
thecustomer’ssteamgenerator,disconnecttheconden-
satetubingfromthemaindrainandconnectittotheop-
tionalcondensatereturntting(See page 2 for location
of this connection).
SETTING OF STEAM GENERATOR PRESSURE
CONTROL SWITCHES (on models before 1979):
To be sure steam generator pressure control switches
aresetproperly,usethefollowingprocedure:
Startsteamgeneratorandallowittobuilduppres-
sure-5or15pounds.
Release pressure into cooking chamber by turning
onunit.
Shutoffcooking unitandletsteamgeneratorbuild
back up to pressure. Check the steam pressure
gauge. If pressure is within 10% of recommended
operatingpressurethepressurecontrolswitchesare
adjustedproperlyandtheunitisoperatingsatisfac-
torily.
Steam generator pressure switches are factory set
1.
2.
3.
4.

INSTALLATION
5
and should not be adjusted unless absolutely nec-
essary.Ifpressureisfoundtobeotherthenabove,
proceedasfollows.
Removefrontcoverfrommodularcontrolbox.
With screwdriver adjust pressure switches (A)
and (B). Steam col steam generators used to
generatedsteam for a Steam-It, Steam Cooker
orKettlewhichoperateat15PSIshouldbeset
as follows: Switch (A) should be steam at 12
PSI and switch (B) should be set at 20 PSI. If
15poundssteamgeneratorisusedfor5pounds
operation, follow above instructions and then
refer to “adjusting watts 3/4” pressure reducing
valve”.
Steam coil steam generator used to generate
steamforcompartmenttypesteamcookerwhich
operatesat5PSIshouldbesetasfollows:Switch
(A)shouldbesetat5PSIandswitch(B)at10
PSI.
DialCisthedifferentialdialandshouldalways
besetat1PSIonbothswitch(A)and(B).
Thecoldwatercondenserthermostat(DialD)is
provided as standard equipment with all auto-
maticdrainsteamgenerators.Thisthermostatis
presetatthefactoryfor140OFandshouldnotbe
re-adjustedintheeld.
•
•
•
•
•
Figure 4
NOTE: On either model steam generators, adjustments
of the pressure control switches may be done with a
screwdriver as shown. Later model steam generators re-
quire the use of a special wrench, which may be obtained
from Market Forge.
    Figure5.

INSTALLATION
6
PRESSURE CONTROL SWITCH ADJUSTMENT
(on models after 1979): Refer to gure 5 on page 5.
Ifgeneratorfailstomaintainsteampressureinoperating
range,pressurecontrolswitchmayrequireadjustment.
Startgeneratorandallowpressuretobuilduptoop-
eratinglevel-15PSI.
Checkgeneratorpressuregauge.Ifgaugeindicates
12to14PSI,pressurecontrolswitchesareproperly
adjusted.
Ifgeneratordoesnotcomeonwhenpressuregauge
reads 12 PSI and does not go off when pressure
gaugereads14PSI,proceedasfollows:
Remove screws and lift front cover off control
box. WARNING: Because power must be on
to adjust pressure switches, be sure to pro-
tect against electrical shock.
Hand adjust operating pressure control switch
(A)andhighlimitpressurecontrolswitch(B)by
turning adjusting nut (Knurled knob) clockwise
toraiseandcounterclockwisetoloweractuation
point.Switch(A)shouldbesetsothatgenerator
comesonwhengeneratorpressuregaugereads
12PSIandgoesoffwhengaugereads14PSI.
Switch (B) should be set so that generator will
shutoffifpressurereaches15PSI.If15pounds
steamgeneratorisusedfor5poundsoperation,
followaboveinstructionsandthereferto“adjust-
ing watts 3/4” pressure reducing valve”.
The actuation valve (differential) is factory set
andcannotbechanged.
The cold water condenser thermostat is pre-
set at the factory for 130OF and should not be
changed.
Repeatsteps1through 3.If12to14 PSIgen-
erator pressure gauge operation, adjustment is
correct. If proper adjustment can not be made,
consult“trouble-shootingguideonpage.
Aftermakingadjustments,replacecoveroncon-
trolbox.
WATER LEVEL CONTROL (on models before 1984):
ThewaterlevelcontrolusedbyMarketForgeisaoat
typeswitchwithaoatballinsidetheboiler.Thewater
levelcontrolisequippedwithtwomicro-switcheswhich
turnthewatersupplyonandoffandthepowersupplyon
andoff(refer to gure 6).
Micro-switch(A)preventsthesourceofpowerfromcom-
ingonuntilthereisanadequatesupplyofwaterinthe
boiler. Micro-switch (B) shut off water supply when the
water level has reached 2/3 full as viewed in the gage
glass.
1.
2.
3.
•
•
•
•
•
•
Figure 6
CAUTION: Beforeremovingcoverdisconnect115Vpow-
ersupply.Whentheboilerisfull,waterlevelshouldreach
2/3fullingaugeglassandthewaterfeedshouldshutoff.
Ifthisisnotcorrect,removecovertowaterlevelcontrol
and adjust micro-switch (B). To adjust, loosen lock nut
andturnscrewclockwisetoraiselevelandcounterclock-
wisetolowerlevel.
Ifnowaterisvisibleingaugeglassandpowercomeson
whenwaterswitchisreset,thisindicatesthat:
Micro-switch(A)isoutadjustmentandmustberead-
justed.Toadjust,removecovertowaterlevelcontrol,
loosenlocknutandturnadjustingscrewclockwise.
Continuethisadjustmentsothatheatdoesnotcome
onuntilthegaugeglassis2/3lledwithwater.
Useohmmeteracrosstocheckforpropercontinuity
throughmicro-switches.
Figure 7
DISASSEMBLY INSTRUCTIONS: Refer to Figure 7.
Removewaterlevelcontrolasfollows:
Remove the two screws (A) on either side and re-
movethecover.
Disconnectthe4initialwiresfromtheirterminalposts
tosimplifyreassembly.
1.
2.
1.
2.

INSTALLATION
7
Removethetwoscrews(B)oneithersideofhousing.
The housing, with all external wiring still attached,
maythenberemovedtooneside.
With an allen set screw wrench remove the set
screwsatthefourcornersofthemountingplate.
Pulloutandremovethecompleteoatassemblyand
gasketfromtheboiler.
Cleantheinternalboilerpartsofthewaterlevelcon-
trol. Use a tooth brush to clean the bellows. If the
depositsareexcessive,aatbladeputtyknifemay
be used to clear accumulations from between the
bellows ns. However, care should be used not to
rupturethemortwistbellowsoutofalignment.When
satised that the complete oat switch assembly is
cleanandthatthebellowsarefreetooperateproper-
ly,reinstallassemblyintotheboilerusinganewgas-
kettoestablisharmseal.Fist,besurethatsurfaces
contactingthegasketarecompletelyclean.Reverse
thedisassemblystepstoreinstallintotheboiler
CAUTION: Be sure to check adjustments as
shown.
WATER LEVEL CONTROL (on models after 1984):
CAUTION: Before removing cover, disconnect power
supply.TheMcDonnell-MillerWaterLevelControlisnot
adjustable.Ifnotfunctioningproperly,entirewaterlevel
controlmustbereplaced.
TO REMOVE WATER LEVEL CONTROL:
Removecoverfromterminals.
Disconnectwires.
Removescrewsfromretainingcollar.
Removeretainingcollar.
Screwwaterlevelcontroloutofboiler.
Toinstallwaterlevelcontrol,reverseaboveinstructions
makingsurethetopofthewaterlevelcontrolhas“TOP”
isuprightbeforetighteningretainingscrews.
WATTS PRESSURE REDUCING VALVE - 3/4”:
Thewattspressurereducingvalveisdesignedtooperate
at7to50PSIsourceofsteampressureandreducethis
to5PSIfrodeliverytoyourcooker.Toprovideadequate
pressureregulation,thisunitmaybeequippedwiththis
valve.Installationmustbemadefromyousourcesteam
supply,throughthepressurereducingvalveandintothe
manifoldinputofthesteamcooker.
Operation of Watts Pressure Reducing Valve - 3/4”: (Re-
fer to Figure 8)Steamentersthe valveattheinletport
and passes up-ward through the seat (8) into the dis-
charge side of the valve.As pressure in the discharge
side increases, it forces the diaphragm (2) upward,
3.
4.
5.
6.
7.
1.
2.
3.
4.
5.
Figure 8
WATTS PRESSURE REDUCING VALVE - 3/4”
ITEM PART # DESCRIPTION
110-1083 ADJUSTING SPRING
2 10-1082 DISPHRAGM
310-1075 DISPHRAGMGASKET
4 10-1076 DISPHRAGM BUTTON STEM ASSY.
510-1077 STRAINER
610-1078 BOTTOM PLUG
7 10-1079 BOTTOM SPRING
810-1080 SEAT
9 10-1081 DISC ASSY.
10 10-1033 3/4” COMPLETE VALVE - ENAMELED
-- 10-1034 3/4” COMPLETE VALVE - CHROME
overcoming the tension of the adjusting spring (1) and
closingvalve.Asthepressuredrops,theadjustingspring
forcesthediaphragmdown,reopeningthevalve.Where
demandandinitialpressuresarefairlyconstant,thevalve
openstotheproper position and maintainsthedesired
reducedpressure.
Adjusting Watts Pressure Reducing Valve - 3/4”:
Release the adjusting screw enough to release all
tensiononadjustingspring(1).
Turnsteamonslowly.Theturnadjustingscrewclock-
wisejustenoughtoallowthevalvetoopenslightly.
Allow generator to operate in this manner several
minutes.
Turnadjustingscrewdownslowly,atintervals,until
reducedpressurereachesthedesiredpoint(5PSI).
Tightenadjustingscrewlocknut.
Ifchatteringnoiseshouldoccurturnadjustingscrew
located in bottom half of valve body clockwise or
counterclockwiseuntilchatteringstops.
1.
2.
3.
4.
5.

INSTALLATION
8

INSTALLATION
9

INSTALLATION
10

INSTALLATION
11

INSTALLATION
12

INSTALLATION
13

INSTALLATION
14

OPERATION
15
START UP:
There are two methods of draining steam generators;
oneisautomaticandtheotherismanual.Todetermine
whichmethodtheunithas,opencabinetdoorsandthere
willbeacontrolboxwithtwoswitchesandanindicator
light.Instructionslabeledonthecontrolboxwillidentify
thesteamgeneratorasbeingautomaticormanual.
AUTOMATIC DRAIN: First check to be sure that:
Waterandheatswitchesareintheoffposition.
Watersupplyvalveisopen.
Electricityisconnectedtoallunits.
Thatsteamisturnedon.
ThenproceedwithDailyOperatingInstructions.
DAILY OPERATING INSTRUCTIONS:
Slipwaterswitchon.
Waituntilgaugeglassis2/3full.
Thenipwaterswitchoffandbackonimmediately.
Indicatorlightwillcomeon.Thisisnecessarytoman-
uallyresettheunit.
Flipheatswitchon.Thisheatsthewater.
•
•
•
•
•
1.
2.
3.
4.
UNITS MANUFACTURED AFTER 1983,
EQUIPPED WITH “MOMENTARY” HEAT SWITCH:
Daily Operating Instructions:
Flipwaterswitchon.
Wait6minutesforwatertollinboiler,gaugeglass
shouldread2/3full.
Flipheatswitchonandreleasebackonimmediately,
indicatorlightwillcomeon,thisisnecessarytoman-
uallyresettheunit.Thisalsoturnsontheheat.
Daily Shut Down for units Manufactured after 1983:
Flipheatandwaterswitchestooff.Indicatorlightwillgo
outandsteamgeneratorwillgooutandsteamgenerator
willautomaticallydrain.
Manual Drain Steam Generator for units Manufactured
after 1983: First check to be sure that:
Waterandheatswitchesareoff.
Watersupplyvalveisopen.
Electricityisconnectedtoallunits.
Thatsteamisturnedon.
Thenproceedwithdailyoperatinginstructions.
1.
2.
3.
•
•
•
•
•

INDICATOR LIGHT
ON

OFF
WATER SWITCH
ON

OFF
HEAT SWITCH
WARNING:
DO NOT HOSE DOWN UNIT AS IT CONTAINS ELECTRICAL COMPONENTS.

TROUBLE-SHOOTING
16
TROUBLE-SHOOTING GUIDE:
BOILER FAILS TO REACH FULL OPERATING PRESSURE OF 5 OR 15 POUNDS.
PRESSURE GAUGE READS INACCURATELY.
PRESSURE CONTROL AND HIGH LIMIT CONTROL SWITCH-
ES ARE OUT OF ADJUSTMENT.
SAFETY VALVE NOT SEATING PROPERLY.
WATER LEVEL TOO HIGH.
STEAM TRAP ON UNITS RECEIVING STEAM FROM BOILER
NOT CLOSING SUFFICIENTLY AFTER VENTING.
AIR VENTAND VACUUM BREAKER NOT VENTING PROP-
ERLY.
INSUFFICIENT STEAM SUPPLY.
1.
2.
3.
4.
5.
6.
7.
REPLACE.
FOLLOW INSTRUCTIONS FOR ADJUSTING.
CLEAN OR REPLACE.
ADJUST WATER LEVEL CONTROL.A) CHECK WATER FEED
VALVEFORSTICKING.B)CLEANORREPLACE.
REPLACE ELEMENT IN STEAM TRAP OF UNIT BEING FED
STEAM FROM BOILER.
REPLACE.
SEE INSTRUCTIONS ON STEAM ADJUSTMENTS.
1.
2.
3.
4.
5.
6.
7.
BOILER FAILS TO CUT OFF AFTER REACHING OPERATING PRESSURE.
DEFECTIVE STEAM GAUGE READING.
PRESSURE SWITCH SET TOO HIGH OR DEFECTIVE.
STEAM SOLENOID VALVE FAILS TO CUT OFF WHEN DE-
MANDS OF PRESSURE SWITCH HAVE BEEN MET.
1.
2.
3.
SHUT DOWN BOILER AND RELIEVE ALL PRESSURE. STEAM
GAUGE INDICATOR SHOULD RETURN TO ZERO. IF DEFEC-
TIVE, REPLACE.
ADJUST OR REPLACE IF DEFECTIVE.
REPLACE STEAM SOLENOID VALVE.
1.
2.
3.
SAFETY VALVE BLOWS OFF PREMATURELY.
PRESSURE SET TOO HIGH.
PRESSURE GAUGE READS INCORRECTLY.
LIME OR DIRT ON SEAT OF VALVE.
WEAKSPRINGINVALVE.
1.
2.
3.
4.
READJUST.
REPLACE.
CLEAN.
REPLACE.
1.
2.
3.
4.
BOILERBUILDSUPTOPRESSURE,SHUTSDOWNANDFAILSTOCOMEBACKON.
HIGH LIMIT SWITCH SET TOO LOW OR OPERATING PRES-
SURE CONTROL SWITCH SET TOO HIGH.
1. READJUST. REPLACE IF DEFECTIVE.1.
BOILER CUTS OUT AFTER 10-15 MINUTES OF OPERATION.
DEFECTIVE TIME DELAY RELAY.
POORSOLDERCONNECTIONSONRELAYSOCKET.
1.
2.
REPLACE RELAY.
RESOLDERCONNECTIONSONRELAYSOCKET.
1.
2.
AIRVENTANDVACUUMBREAKERLEAKING.
NOT CLOSING.1. REPLACE.1.
COLD WATER CONDENSER DOES NOT FUNCTION.
MAIN WATER LINE SHUT OFF.
THERMOSTAT OUT OF ADJUSTMENT OR DEFECTIVE.
LOOSE CONNECTION.
SOLENOID VALVE DEFECTIVE.
1.
2.
3.
4.
TURN ON.
READJUST FOR PROPER OPERATION OR REPLACE OF DE-
FECTIVE.
TIGHTEN.
CHECKCOILFORCONTINUITY,IFOPENREPLACE.
1.
2.
3.
4.
PRESSURE REDUCING VALVE CANNOT BE ADJUSTED.
DIRTY SCREEN AND SEAT.
DISC ASSEMBLY DEFECTIVE.
DIAPHRAGM RUPTURED.
1.
2.
3.
CLEAN.
REPLACE.
REPLACE.
1.
2.
3.
PRESSURE REDUCING VALVE DOESN’T LET SUFFICIENT STEAM INTO COMPARTMENT.
DIRTY STRAINER SCREEN.1. CLEAN OR REPLACE.1.
PRESSURE REDUCING VALVE VIBRATES OR HUMS.
ADJUSTMENT OR SENSITIVITY ADJUSTER.1. READJUST.1.
PRODUCTINCOOKERDOESNOTCOOKPROPERLYONFIRSTCYCLE.
AIR VENT AND VACUUM BREAKER IS CLOSING TOO
SOON.
1. PREHEAT COOKING COMPARTMENTSAND VENT AIR INTO
COMPARTMENT.
1.

TROUBLE-SHOOTING
17
SOLENOID STEAM VALVE FAILS TO OPEN.
LACKOFPOWERTOUNIT.
DIRTY SEAT IN SOLENOID VALVE.
INOPERABLE SOLENOID VALVE.
1.
2.
3.
CHECK110VPOWERSUPPLY.
CLEAN VALVE.
CHECKCOIL.REPLACEIFNECESSARY.
1.
2.
3.
WATER DOES NOT ENTER BOILER.
WATER MAIN SHUT OFF.
POWER NOT REACHING SOLENOID WATER FEEDER.
DEFECTIVE WATER MICROSWITCH IN WATER LEVEL CON-
TROL BOX OR LOOSE CONNECTION.
WATER LEVEL CONTROL MICROSWITCH OUT OF ADJUST-
MENT.
DIRT OR LIME ON SEAT OF RIGHT SOLENOID VALVE IN
CONTROL BOX.
DEFECTIVE SOLENOID COIL ON RIGHT VALVE IN CONTROL
BOX.
DEFECTIVE WATER SWITCH TOGGLE SWITCH ON CON-
TROL BOX.
1.
2.
3.
4.
5.
6.
7.
TURN ON.
CHECK MAIN FUSE AND IF 115V IS PRESENT AT WATER
FEEDER.
CHECK CONTINUITY OR LOOSE CONNECTION, REPLACE
LEFT SWITCH IF DEFECTIVE.
FOLLOW INSTRUCTIONS FOR READJUSTING LEFT MICRO-
SWITCH. IF ADJUSTING OR CLEANING DOES NOT REMEDY,
REPLACE.
CLEAN VALVE STEAM AND LINE STRAINER.
CHECKCOILFORCONTINUITY,REPLACEIFDEFECTIVE.
CHECKCONTINUITY,REPLACEIFDEFECTIVE.
1.
2.
3.
4.
5.
6.
7.
WATER ENTERS BOILER VERY SLOWLY.
DIRTY STRAINER SCREEN ON RIGHT SOLENOID VALVE.
DIRT OR LIME ON SEAT OF RIGHT VALVE.
1.
2.
CLEAN OR REPLACE STRAINER SCREEN.
CLEAN VALVE SEAT.
1.
2.
INDICATOR LIGHT, ON CONTROL BOX, DOES NOT LIGHT WHEN WATER SWITCH IS MANUALLY RESET.
INDICATOR LIGHT DEFECTIVE.
TIME DELAY RELAY LOOSE OR DEFECTIVE.
1.
2.
REPLACE.
CHECK FOR GOOD CONNECTIONS, IF DEFECTIVE, RE-
PLACE.
1.
2.
BOILER OVERFILLS WITH WATER.
WATER LEVEL CONTROL OUT OF ADJUSTMENT.
SOLENOID VALVE FAILS TO CLOSE.
1.
2.
FOLLOW INSTRUCTIONS FOR READJUSTING. IF READJUST-
ING DOES NOT REMEDY, REPLACE MICROSWITCHES. CLEAN
OR REPLACE ENTIRE UNIT.
CLEAN SEAT AND STRAINER VALVE.
1.
2.
BOILER FAILS TO BUILD UP ANY PRESSURE WHEN WATER LEVEL IS PROPER AND HEAT SWITCH IS
TURNED ON.
CHECK TO SEE THAT STEAM IS TURNED ON AND
COMING TO UNIT.
CHECK TO SEE THAT SOLENOID VALVE IS OPER-
ABLE.
CURRENTFLOWISBROKENATWATERLEVELCON-
TROL(ASCERTAINWITHCONTINUITYCHECK).
CURRENT FLOW IS BROKEN AT PRESSURE CON-
TROL OR HIGH LIMIT CONTROL SWITCHES DUE TO
DEFECT(ASCERTAINWITHCONTINUITYCHECK).
1.
2.
3.
4.
TURN ON.
CHECKSOLENOIDVALVE.
CHECKFORVOLTAGETHRUSIDEOFMICROSWITCH,
REPLACE IF DEFECTIVE.
READJUST TO PROPER SETTING, REFER TO INSTRUC-
TION FOR READJUSTMENT, REPLACE IF DEFECTIVE.
1.
2.
3.
4.
WATER LEVEL IN GAUGE GLASS FLUCTUATES UP AND DOWN.
TOP SHUT OFF ON WATER GAUGE IS CLOSED.1. OPEN.1.

ILLUSTRATED PARTS
18
WATER LEVEL AND STEAM CONTROL
ITEM PART # DESCRIPTION
1 09-4887 McDONNELL LOW WATER CUT OFF (ON UNITS AFTER 1984)
1A 90-8929 MARKETFORGELOWWATERCUTOFF(ONUNITSBEFORE1984)
210-4612 GAUGE GLASS
3 10-4576 GAUGE GLASS ASSY WITH GAURDIAN RODS - R. H.
410-3474 COUPLING, PLAIN, R. H. SCREWED 1/2”
5 10-4556 AIR VENT
691-3311 REWORKEDSTEAMTRAP
7 10-5785 HAYS SOLENOID STEAM VALVE NC 115V
7A 10-6452 HAYS SOLENOID STEAM VALVE NC 240V