Williamson GWI-127 User manual

Category
Water heaters & boilers
Type
User manual

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G W I
Boiler Manual
Series 2
Gas-Fired Water Boilers
Part Number 550-142-785/0812
This manual must only be used by a qualified heating installer/service technician. Failure to comply could result in
severe personal injury, death or substantial property damage.
When calling or writing about the boiler— Please have:  •  boiler model number from the boiler rating label  and
•CPnumberfromtheboilerjacket.YoumaylisttheCPnumberinthespaceprovidedonthe“Installationandservice
certicate”foundonpage 21.
Hazards that will or can cause minor personal
injury or property damage.
Special instructions on installation, operation or
maintenance that are important but not related to
personal injury or property damage.
INSTALLER Readallinstructionsbeforein-
stalling. Read page 2 first. Follow all instructions
in proper order to prevent personal injury or death.
• Considerpipingandinstallationwhendetermining
boiler location.
• Anyclaimsfordamageorshortageinshipment
must be filed immediately against the transporta-
tion company by the consignee.
USER — Please read the following. Failure to
comply could result in severe personal injury,
death or substantial property damage.
• This manual is for use only by your qualified
heating installer/service technician.
• PleaseseetheUser’sInformationManualforyour
reference.
• Have the boiler serviced by a qualied service
technician, at least annually.
Hazards that will cause severe personal injury,
death or substantial property damage.
Hazards that can cause severe personal injury,
death or substantial property damage.
Hazard definitions
Contents Page
1 Prepare boiler location .......................................................2
2 Prepare boiler .....................................................................6
3 Vent installation ..................................................................7
4 Installwaterpiping ............................................................13
5 Installgaspiping ...............................................................16
6 Field wiring .......................................................................17
7 Start-up ............................................................................18
8 Checkoutprocedure .........................................................20
9 DepartmentofEnergyCompliance .................................. 21
9a Sequenceofoperation .....................................................22
10 Operating instructions ......................................................26
11 Service and maintenance .................................................27
12 Troubleshooting ................................................................31
13 Replacement parts ........................................................... 41
14 Dimensions .......................................................................46
15 Ratings .............................................................................47
2Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Installations must follow these codes:
• Local,state,provincial,andnationalcodes,laws,regulations
and ordinances.
• NationalFuelGasCode,ANSIZ223.1–latestedition.
• StandardforControlsandSafetyDevicesforAutomatically
FiredBoilers,ANSI/ASMECSD-1,whenrequired.
• NationalElectricalCode.
• ForCanadaonly:B149.1orB149.2InstallationCode,CSA
C22.1CanadianElectricalCodePart1andanylocalcodes.
Certification
 TheGWIboilergasmanifoldandcontrolsmetsafe
lightingandotherperformancecriteriawhenboiler
underwent tests specied in ANSI Z21.13–latest
edition.
Before locating the boiler:
Checkfornearbyconnectionto:
• Systemwaterpiping
• Ventingconnections
• Gassupplypiping
• Electricalpower
Checkareaaroundboiler.Removeanycombustiblematerials,
gasolineandotherammableliquids.
 Failuretokeepboilerareaclearandfreeofcom-
bustible materials, gasoline and other flammable
liquids and vapors can result in severe personal
injury, death or substantial property damage.
Boiler must be installed so that gas control system components
areprotectedfromdrippingorsprayingwaterorrainduring
operation or service.
Ifnewboilerwillreplaceexistingboiler,checkforandcorrect
system problems, such as:
1. Systemleakscausingoxygencorrosionorsectioncracks
fromhardwaterdeposits.
2. Incorrectly-sizedexpansiontank.
3. Lackofantifreeze(whenrequired)inboilerwatercausing
systemandboilertofreezeandleak.
Failure to adhere to the guidelines below can
result in severe personal injury, death or sub-
stantial property damage.
When servicing boiler —
1. To avoid electric shock, disconnect electrical supply
beforeperformingmaintenance.
2. Toavoidsevereburns,allowboilertocoolbeforeper-
formingmaintenance.
Boiler operation —
3. Donotblockowofcombustionorventilationairtoboiler.
4. Shouldoverheatingoccurorgassupplyfailtoshutoff,do
notturnoffordisconnectelectricalsupplytocirculator.
Instead,shutoffthegassupplyatalocationexternalto
the appliance.
5. Donotusethisboilerifanyparthasbeenunderwater.
Immediatelycallaqualiedservicetechniciantoinspect
theboilerandtoreplaceanypartofthecontrolsystem
and any gas control that has been under water.
Boiler water —
6. DO NOT use petroleum-based cleaning or sealing com-
pounds in boiler system. Water seal deterioration will oc-
cur,causingleakagebetweenboilersections,circulator
anges,diaphragmtanksorothersystemcomponents.
This can result in substantial property damage.
7. DO NOT use“homemade cures” or“boiler patent
medicines”. Serious damage to boiler, personnel and/
or property may result.
8. Continualfreshmakeupwaterwillreduceboilerlife.Min-
eralbuildupinsectionsreducesheattransfer,overheats
castiron,andcausessectionfailure.Additionofoxygen
and other gases can cause internal corrosion. Leaks
in boiler or piping must be repaired at once to prevent
makeupwater.
9. Donotaddcoldwatertohotboiler.Thermalshockcan
causesectionstocrack.
Glycol — potential fire hazard —
Allglycolisammablewhenexposedtohightemperatures.If
glycol is allowed to accumulate in or around the boiler or any
otherpotentialignitionsource,arecandevelop.Inorderto
prevent potential severe personal injury, death or substantial
propertydamagefromreand/orstructuraldamage:
• Never store glycol of any kind near the boiler or any
potential ignition source.
• Monitorandinspectthesystemandboilerregularlyfor
leakage.Repairanyleaksimmediatelytopreventpos-
sibleaccumulationofglycol.
• Neveruse automotiveantifreezeor ethyleneglycol in
thesystem.Usingtheseglycolscanleadtohazardous
leakageofglycolintheboilersystem.
1 Prepare boiler locationRead this first!
Codes & checklist
The boiler contains ceramic fiber and fiber-
glassmaterials.Usecarewhenhandlingthese
materials per instructions on page 48ofthis
manual. Failure to comply could result in severe
personal injury.
3
Part Number 550-142-785/0812
Service clearances
1. Provideminimumclearancesforcleaningandservicingthe
boilerandforaccesstocontrolsandcomponentsaslistedin
the table below:
2. Provideatleastscrewdriverclearancetojacketfrontpanel
screws for removal of front panel for inspection and minor
service.Ifunabletoprovideatleastscrewdriverclearance,
installunionsandshutoffvalvesinsystemsoboilercanbe
movedforservicing.
Small space installations
1. When the boiler is located in a closet or small space, provide
clearances no less than those shown in Figure 1. The clear-
ancesarerequiredto anysurface,whethercombustibleor
non-combustible.
Table 1 Minimum foundation size
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Service clearances: Minimum
Top (for cleaning flueways) 35”
Front (for access to controls and components) 18”
Back 7”
Leftside (for cleaning and servicing) 24”
Right side 7”
Boiler
model
Minimum
foundation
length
Minimum
foundation
width
GWI-047 25” 12”
GWI-063 25” 12”
GWI-095 25” 15”
GWI-127 25” 18”
GWI-158 25” 21”
GWI-190 25” 24”
Minimum clearance to combustible materials
1. Hotwaterpipesmustbeatleast½”fromcombustiblematerial.
2. Single-wallventpipemustbeatleast2inchesfromcombus-
tible material.
3. TypeBdouble-wallmetalventpipe—seeventmanufacturer’s
recommendationforclearancestocombustiblematerial.
Figure 1 Minimum clearances
Flooring and foundation
Flooring
TheGWIboilerisapprovedforinstallationoncombustibleooring,
but must never be installed on carpeting.
 Donotinstallboileroncarpetingeveniffoundation
is used. Fire can result, causing severe personal
injury, death or substantial property damage.
Foundation
1. Provideasolidbrickorminimum2-inchthickconcretefounda-
tionpadifanyofthefollowingistrue:
• oorcanbecomeooded.
• theboilermountingareaisnotlevel.
2. See Table 1forminimumfoundationdimensions.
Residential garage installations
Takethefollowingspecialprecautionswheninstallingtheboilerin
aresidentialgarage,perANSIZ223.1,paragraph5.1.9:
• Mounttheboileraminimumof18 inches above the floorof
the garage to assure the burner and ignition devices will be
no less than 18 inches above the floor.
• Locateorprotect the boiler so it cannot be damaged by a
moving vehicle.
1 Prepare boiler location continued
Clearances
4Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
1 Prepare boiler location continued
 Failuretofollowallinstructionscanresultinuegas
spillageandcarbonmonoxideemissions,causing
severe personal injury or death.
When removing boiler from existing common vent system:
Atthetimeofremovalofanexistingboiler,thefollowingsteps
shall be followed with each appliance remaining connected to
the common venting system placed in operation, while the other
appliances remaining connected to the common venting system
are not in operation.
a. Seal any unused openings in the common venting system.
b. Visuallyinspecttheventingsystemforpropersizeandhori-
zontalpitchanddeterminethereisnoblockageorrestriction,
leakage,corrosionorotherdeciencieswhichcouldcausean
unsafecondition.
c. Testventsystem—Insofarasispractical,closeallbuilding
doors and windows and all doors between the space in which
the appliances remaining connected to the common venting
system are located and other spaces of the building.Turn
on clothes dryers and any appliance not connected to the
commonventingsystem.Turnonanyexhaustfans,suchas
rangehoodsandbathroomexhausts,sotheywilloperateat
maximumspeed.Donotoperateasummerexhaustfan.Close
fireplace dampers.
d. Place in operation the appliance being inspected. Follow the
lighting/operatinginstructions.Adjustthermostatsoappliance
will operate continuously.
e. Testforspillageatdrafthoodreliefopeningafter5minutesof
mainburneroperation.Usetheameofamatchorcandle.
f. Afterithasbeendeterminedthateachapplianceremaining
connected to the common venting system properly vents when
testedasoutlinedabove,returndoors,windows,exhaustfans,
fireplace dampers, and any other gas-burning appliance to
theirpreviousconditionsofuse.
Any improper operation of common venting system should be
corrected so the installation conforms with the National Fuel
GasCode,ANSIZ223.1–latestedition.Correctbyresizingto
approach the minimum size as determined using the appropriate
tablesinPart11ofthatcode.Canadianinstallationsmustcomply
withB149.1orB149.2InstallationCode.
Chimney draft vent requirements
1. Venting must be installed according to Part 7, Venting of
Equipment,ofNationalFuelGasCode,ANSIZ223.1-latest
editionandapplicablebuildingcodes.Canadianinstallations
mustcomplywithB149.1orB149.2InstallationCodes.
2. Chimneyorventtermination:
• Achimney,oranyventotherthanaTypeBventwithlisted
ventcap,mustextendatleast3feetabovethehighest
pointwhereitpassesthrougharoofofabuilding,andat
least2feethigherthananyportionofabuildingwithina
horizontaldistanceof10feet.
• TypeBventswithlistedcapsmayterminateasinFigure2
ifnocloserthan8feetfromaverticalwallorsimilarob-
struction.
• Otherwise,Type B ventsmustterminate at least2 feet
abovetheroofpenetrationandatleast2feethigherthan
anyportionofabuildingwithin10feet.
3. Alinedchimneyispreferredandmustbeusedwhenrequired
by local, state, provincial and national codes, laws, regulations
and ordinances. Vitreous tile linings with joints that prevent
retentionofmoistureandliningsmadeofnoncorrosivemateri-
alsarebest.Adviceforueconnectionsandchimneylinings
canbeobtainedfromlocalgasutility.TypeBdouble-wallmetal
vent pipe or single-wall vent pipe may be used as a liner.
4. Cold masonrychimneys,alsoknownas outside chimneys,
typicallyhaveoneormorewallsexposedtooutsideair.
When any atmospheric gas-fired boiler with automatic vent
damperisventedthroughthistypeofchimney,thepotential
existsforcondensationtooccur.Condensationcandamage
amasonrychimney.Manufacturerrecommendsthefollowing
to prevent possible damage.
a. Linechimneywithcorrosion-resistantmetallinersuchas
AL29-4C®single-wallstainlesssteelorB-vent.Sizeliner
perNationalFuelGasCodeANSIZ223.1–latestedition.
b. Provide drain trap to remove any condensate.
5. Where two or more gas appliances vent into a common chim-
neyorvent,equivalentareashouldbeatleastequaltoareaof
ventoutletonlargestapplianceplus50percentofventoutlet
areaofadditionalappliance.
Direct exhaust venting (Category III)DO NOT
COMMON venttheGWIinadirectexhaustsystem
(CategoryIII).Connectingmorethanoneappliance
toadirectexhaustsystemwillcauseuegasspill-
ageorappliancemalfunction,resultinginpossible
severe personal injury, death or substantial property
damage.
Inspect existing chimney before installing boiler.
Failure to clean or replace perforated pipe or tile
lining will cause severe personal injury or death.
Vent system
GWI boilers can be either chimney draft vented
or direct-exhaust vented. See pages 7 to 12 for
detailed installation instructions.
 Ifyouareremovinganexistingboilerfromashared
ventingsystemandthenewGWIboilerwillnotshare
theventsystem(allowedonlywhenchimneydraft
venting),youmusttesteachremainingappliance
individuallytoverifytheventsystemstilloperates
adequately.Followguidelinesbelow.
Figure 2 Terminations with Type B vent tted with listed
cap, provided vent is at least 8 feet from any
vertical wall or similar obstruction.
5
Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Products to avoid
Spray cans containing chloro/fluorocarbons
Permanent wave solutions
Chlorinatedwaxes/cleaners
Chlorine-basedswimmingpoolchemicals
Calciumchlorideusedforthawing
Sodiumchlorideusedforwatersoftening
Refrigerantleaks
Paint or varnish removers
Hydrochloric acid/muriatic acid
Cementsandglues
Antistaticfabricsoftenersusedinclothesdryers
Chlorine-typebleaches,detergents,andcleaningsolvents
foundinhouseholdlaundryrooms
Adhesivesusedtofastenbuildingproductsandothersimilar
products
Areas likely to have contaminants
Dry cleaning/laundry areas and establishments
Swimming pools
Metalfabricationplants
Beauty shops
Refrigerationrepairshops
Photo processing plants
Autobodyshops
Plasticmanufacturingplants
Furniture refinishing areas and establishments
New building construction
Remodeling areas
Garageswithworkshops
Table 2 Corrosive contaminants and likely locations
To prevent potential of severe personal injury or
death, check for products or areas listed below
beforeinstallingboiler.Ifanyofthesecontaminants
arefound:
• removecontaminantspermanently.
— OR —
• isolateboilerandprovideoutsidecombustion air.
Seenational,provincialorlocalcodes forfurther
information.
Pleasereviewthefollowinginformationonpotentialcombustion
air contamination problems.
See Table 2forproductsandareaswhichmaycausecontami-
nated combustion air.
Air contamination Air openings
1 Prepare boiler location continued
CombustionairandventilationopeningsmustcomplywithSec-
tion 5.3,“Air for Combustion andVentilation”, of National Fuel
GasCodeANSIZ223.1–latestedition,orapplicablelocalbuilding
codes.CanadianinstallationsmustcomplywithB149.1orB149.2
InstallationCodes.
Seetablebelowforminimumcombustion/ventilationairopening
sizes.Whereopeningsarerequired,providetwo(2)openings—
onewithin12inchesoftheceiling,theotherwithin12inchesof
the floor, as shown in the table illustrations.
 Provideadequatecombustionandventilationairto
assurepropercombustionandreducetheriskof
severe personal injury, death or substantial property
damage caused by flue gas spillage and carbon
monoxideemissions.
6Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Location Natural gas Propane gas
U. S.
Sea level –
2,000 ft over
2,000 ft Sea level –
2,000 ft over
2,000 ft
2.00 mm (Note1) 1.30 mm (Note1)
Canada
Sea level –
2,000 ft 2,000 –
4,500 Sea level –
2,000 ft 2,000 –
4,500
2.00 mm 1.90 mm 1.30 mm 1.20 mm
Note1: ForU.S.elevationsabove2,000feet,contactyourlocalsupplierfor
details.
1 Prepare boiler location continued
Exhaust fans and air movers
The appliance space must never be under a negative pressure.
Always provide air openings sized not only to the dimensions
requiredfortheringrateof allappliances,butalsoto handle
theairmovementrateoftheexhaustfansorairmoversusingair
fromthebuildingorspace.
Air openings continued
2 Prepare boiler
Place boiler/crate near position
1. Leaveboilerincrateandonpalletuntilinstallationsiteisready.
2. Moveentirecrateandpalletnexttoselectedlocation.
3. Removecrate.Leaveboileronpallet.
4. Removeboilerfrompalletasfollows:
a. Tiltleftsideofboilerupandplaceaboardunderleftlegs.
b. Tilt boiler the other way and place a board under right legs.
c. Slideboilerbackwardsoffpalletandintoposition.
 Donotdropboilerorbumpjacketonoororpallet.
Damage to boiler can result.
5. Checklevel.
a. Shimlegs,ifnecessary.
b. Do not alter legs.
Placement and setup
Motorized air dampers
Iftheairopeningsarettedwithmotorizeddampers,electrically
interlockthedamperto:
• Preventtheboilerfromringifthedamperisnotfullyopen.
• Shuttheboilerdownshouldthedampercloseduringboiler
operation.
Toaccomplishthisinterlock,wireanisolated contact(provingthe
damperopen)inserieswiththethermostatinputto the boiler.
Theboilerwillnotstartifthiscontactisopen,andwillshutdown
should it open during operation.
The boiler contains ceramic fiber and fiberglass
materials.Usecarewhenhandlingthesematerials
per instructions on page 48ofthismanual.Failure
to comply could result in severe personal injury.
Inspect orifices and burners
1. Removefrontjacketdoor.Removebaseaccesspanel(See
Figure 25, item 4, page 42).
2. Checkforcorrectly-sizedmanifoldorices. SeeTable 3for
sizing.(Theoricesizeisstampedontheoricespudbarrel.)
Correctly-sized manifold orices must be used.
Failure to do so will result in severe personal injury,
death or substantial property damage.
3. Levelandstraightenburners.
Burners must be properly seated in slots in burner
restwiththeiropeningsfacingup.Mainburnerori-
cesmustinjectdowncenterofburner.Failureto
properly seat burners will result in severe personal
injury, death or substantial property damage.
4. Reinstall access panel.
Do not operate boiler without access panel secured
in place. Failure to comply could cause momentary
amerolloutonignitionofmainame,resultingin
possible fire or personal injury hazard.
Table 3 Manifold orice sizing
7
Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Perform hydrostatic pressure test
Pressure test boiler before attaching water or gas piping or
electricalsupply(exceptasnotedbelow).
Prepare boiler for test
1. Removetheshippingnipple(fromGWIsupplytapping)and
removetheboilerreliefvalve.Temporarilyplugthereliefvalve
tapping with a ¾” NPT pipe plug.
2. Remove1¼”nipple,reducingteeand drainvalvefromac-
cessorybag.Installinboilerreturnconnectionasshownon
in Figure 27, item 3, page 44.Installcirculatoroneitherthe
return or supply.
3. Remove 1¼” nipple, 1¼” tee, bushing and pressure/tempera-
turegaugefromaccessorybag.Pipetoboilersupplyconnec-
tion as shown in Figure 27, item 2, page 44.(Usepipedope
sparingly.)
4. Connectahosetoboilerdrainvalve,theotherendconnected
toafreshwatersupply.Makesurehosecanalsobeusedto
drainboileraftertest.
5. Connectanippleandshutoffvalvetosystemsupplyconnec-
tion on the 1¼” tee. This valve will be used to bleed air during
thell.(Valveandnipplearenotincludedwithboiler.)
6. Connectanippleandshutoffvalvetosystemreturnconnec-
tion(atcirculatorangeifcirculatorinstalledonreturn).This
valvewillbeusedtobleedairduringthell.(Valveandnipple
arenotincludedwithboiler.)
Fill and pressure test
1. Opentheshutoffvalvesyouinstalledonsupplyandreturn
connections.
Pressure test
2. Slowlyopenboilerdrainvalveandfreshwatersupplytoll
boiler with water.
3. Whenwaterowsfromshutoffvalves,closeboilerdrainvalve.
4. Closeshutoffvalves.
5. Slowlyreopenboilerdrainvalveuntiltestpressureofnotmore
than 45 psi is reached on the pressure/temperature gauge.
6. Testatnomorethan45psifornomorethan10minutes.
 Donotleaveboilerunattended.Acoldwaterllcould
expandandcauseexcessivepressure,resultingin
severe personal injury, death or substantial property
damage.
7. Make sure constant gauge pressure has been maintained
throughouttest.Checkforleaks.Repairiffound.
 Leaksmustberepairedatonce.Failuretodoso
can damage boiler, resulting in substantial property
damage.
Do not use petroleum-based cleaning or sealing
compounds in boiler system. Severe damage to
boiler will occur, resulting in substantial property
damage.
Drain and remove fittings
1. Disconnectllwaterhosefromwatersource.
2. Drain boiler at drain valve or out hose, whichever provides
bestaccesstodrain.Removehoseafterdrainingifusedto
drain boiler.
3. Removenipplesandvalvesunlesstheywillremainforusein
the system piping.
4. Removeplugfromreliefvalvetapping.Seepage13toreplace
reliefvalve.
3 Vent installation
TheGWIboilercanbeventedusingoneofthefollowingmethods:
 Useonlytheventmaterialsandmethodsoutlined
inthismanual.Useofanyothermaterialsormeth-
odscouldresultinventfailureoruegasleakage,
causing severe personal injury, death or substantial
property damage.
Chimney draft venting
—Usesthenaturaldraftprovidedbyaverticalventorchimney.
Whenventedusingchimneydraftventing,GWIboilersarerated
asCategoryIappliances(nopressureinventanduegastem-
peraturehotenoughtoavoidexcessiveventcondensation).See
followingsectionforinstallationprocedures.
Chimneydraftinstallationsuse:
a. Ventconnector(singleordoublewall)sizedtoeliminatepositive
pressure in vent system. Diameter increases immediately at
boiler. See Figure 3, page 8forconnectorsizing.
b. Double-wallmetalvent(B-vent)orchimneywithlinerapproved
bytheNationalFuelGasCode,ANSIZ223.1–latestedition,
orinCanadaB149.1orB149.2InstallationCode.
Direct exhaust — vertical or sidewall
Vent pipe is pressurized and terminated vertically through the
rooforthroughasidewall.Whenventedasdirectexhaust,GWI
boilersareratedasCategoryIIIappliance(positivepressurein
theventanduegastemperaturehotenoughtoavoidexcessive
ventcondensation).
Youmustuseonlytheventmaterialslistedinthismanual.See
pages 8 through 12 forinstallationprocedures.
Directexhaustinstallationsuse:
a. Vent materials specified in this manual.
b. Ventterminationthroughoutsidewall,rooforunusedchimney.
(Tightchimneyareaswillmakeventjointconstructionvery
difcult.)
GWI venting options
2 Prepare boiler continued
8Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
3 Vent installation continued
Chimney draft venting
Inspect existing chimney before installing boiler.
Failuretocleanorreplaceperforatepipeorlining
will cause severe personal injury or death.
Vent sizing given in Figure 3 is only a general
guideline. The vent connector and chimney must
be designed, sized and constructed in compliance
with all applicable codes. Failure to correctly size
and install the vent system could result in severe
personal injury, death or substantial property dam-
age.
See page 4foradditionalrequirementswhenchim-
neydraftventing.
1. Usedoublewallmetalvent(B-vent)orchimneywithlineras
requiredbytheNationalFuelGasCode,ANSIZ223.1–latest
edition,orinCanada,B149.1orB149.2InstallationCode.
2. Topreventdowndrafts,chimneyshouldextendatleast3feet
abovethehighestpointwhereitpassesthrougharoofand
atleast2feethigherthananyportionofabuildingwithina
horizontaldistanceof10feet.
3. Toventwithanotherappliance,seeNationalFuelGasCode,
ANSIZ223.1–latesteditionorinCanadaB149.2orB149.2
InstallationCode
4. Donotconnectbreechingtoanyportionofamechanicaldraft
system that can operate under positive pressure.
5. Maintainminimum2”clearancefromcombustiblematerials
to vent pipe.
6. Do not use chimney with an open fireplace.
7. Make horizontal runs as short as possible. Long runs can
cause condensation.
8. When longer runs are used, support pipe with appropriate
hangers.
9. Topreventblockage,donotventintobottomofchimney.
10.Ventpipemustnotgobeyondinsidewallofchimney.
11. Vent passing through floors or ceilings must be firestopped.
12. See Figure 3 to connect boiler to venting system.
Figure 3 Chimney draft venting installation
9
Part Number 550-142-785/0812
Table 4 Maximum vent length
Max.vent length
(feet)
Total number of 90° elbows
(Notes 1 & 2)
1 2 3 4 5 6
GWI-047 to GWI-158 55 48 41 34 27 20
GWI-190 35 28 21 14 7 --
Notes:
1. Do not include termination fitting when counting total number of elbows.
2. One (1) 90° elbow is equivalent to two (2) 45° elbows.
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Direct exhaust venting
Obtain vent system components
1. ThefollowingspecialgasventsystemscomplywithUL-1738
andULC-S636standardsandarecertiedbyCSAastheonly
systemssuitableforusewithGWIboilers(all3”diameter):
• Heat-Fab,Inc.Saf-TVent®
• Flex-LInternational,Inc.StaR-34
• Z-Flex®,Inc.Z-VentII
• ProTechSystemsFasNSeal™
 Useonlytheventstarterofthesamemanufacturer
astheventcomponents.Donotmixcomponents
fromdifferentsystems.Theventsystemcouldfail,
causing flue gas spillage, resulting in severe per-
sonal injury or death.
2. Selectverticalorsidewallventingdependingonjobrequire-
ments.
3. RefertoTable4formaximumventrunlengthsandnumberof
elbows.DonotexceeddatainTable 4.
4. SelectventcomponentsfromseparateGWI Vent Component
Supplement.Allcomponents,includingtheventstarter,must
beofthesameventmanufacturer.Donotmixcomponents.
1. Select a vent pipe manufacturer from separate GWI Vent
Component Supplement and obtain all vent components
needed, based on boiler location and venting method.
2. Youmustusetheventstarter(seebelow)madebytheventpipe
manufacturer.SeeGWI Vent Component Supplementfor
partnumberofeachcomponent,listedbyventmanufacturer.
 Useonlytheventstarterofthesamemanufacturer
astheventcomponents.Donotmixcomponents
fromdifferentsystems.Theventsystemcouldfail,
causing flue gas spillage, resulting in severe per-
sonal injury or death.
3. Follow all applicable national, state, local or provincial codes
whenventingtheGWIboiler.
4. Connectventstartertoblowerhousingoutletasshownbelow.
a. Donotmixcomponentsfromdifferentventmanufacturers.
b. Maintainminimum2”clearancefromcombustiblematerials
to vent pipe.
c. Seal with sealant specied by vent pipe manufacturer,
using 3/8”bead(notrequiredforFasNSeal™).
d. Tighten strap at band clamp screw until strap is snug
around blower housing.
3 Vent installation continued
10 Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Direct exhaust venting continued
1. Locatetheboilerandventpenetrationthroughthewallsoall
requirementsonthispageandinFigures 4 and 5 will be met.
Alsofollowventmanufacturer’sinstructions.
2. Gaseswillformwhiteplumeinwinter.Plumecouldobstruct
window view.
3. Prevailing winds could cause freezing of condensate and
water/icebuilduponventtermination,building,plantsorroof.
Icebuilduponventterminationcancause boiler shutdown
andbuildingfreeze-up.
4. Windsover31mphcancausenuisanceboilershutdownif
boilerissidewallvented.Thiscouldresultinlossofheatto
building,causingfreeze-up.
5. Locateorguardventterminationtopreventcondensatefrom
damagingexteriorsurfaces.
6. Locatetheventterminationwellawayfromtrees,shrubs,and
decorative items.
7. Locateorguardventtopreventaccidentalcontactbypeople
or pets.
8. Do not terminate vent in window well, stairwell, alcove, court-
yard, or other recessed areas.
9. Do not wrap or insulate vent pipe or fittings.
10.Donotterminateventaboveanydoororwindow.Condensate
canfreeze,causingiceformations.
11. Do not connect:
• Anyotherappliancetoventpipe.
• Multipleboilerstoacommonventpipe.
12.Canadianinstallations—SeeB149.1orB149.2Installation
Code.Terminateventnolessthan6feetfromanothercom-
bustionairinlet,3feetfromanyotherbuildingopening,and
3feetfromanygasserviceregulator.
13. See Figures 4 and 5, showing that the vent must terminate:
• atleast7feetabovepublicwalkway.
• 3feetaboveanyforcedairintakewithin10feet.
• morethan4feetbelowortosideofalldoorsorwindows.
• morethan1footabovegradeoranticipatedsnowline.
14. Vent must also terminate:
• atleast6feetawayfromadjacentwalls.
• nocloserthan5feetbelowroofoverhang.
• atleast4feethorizontally(andinnocaseaboveorbelow
unless a 4 foot horizontal distance is maintained) from
electricmeters,gasmeters,regulators,reliefvalves,and
otherequipment.
15. Site conditions may dictate greater clearances.
16.Donotextendexposedventpipeoutsideofbuilding.Conden-
satecouldfreezeandblockventpipe.
 Agasventextendingthroughanexteriorwallshall
not terminate adjacent to the wall or below building
extensionssuchaseaves,overhangs,balconiesor
decks.Failuretocomplycouldresultinsevereper-
sonal injury, death or substantial property damage.
Vent termination location
Follow instructions on this page when determining
ventlocationtoavoidpossibilityofseverepersonal
injury, death or substantial property damage.
Figure 4 Maintain minimum clearances from public
walkways and building air openings
Figure 5 Maintain minimum clearances from doors,
windows and snow line
3 Vent installation continued
11
Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Direct exhaust venting continued
1. Donotmixtypesormanufacturersofventmaterials.
 Useonlytheventstarterofthesamemanufacturer
astheventcomponents.Donotmixcomponents
fromdifferentsystems.Theventsystemcouldfail,
causing flue gas spillage, resulting in severe per-
sonal injury or death.
2. Clean all joints beforesealing. See ventmanufacturer’s in-
structionsforcleaningandsealingjoints.Usetheirspecied
sealant. Do not use screws.
3. Installventpipewithseamsontopofventhorizontalruns.
Followrequirementsonpage 10forventterminationlocation.
4. Maintainminimum2”clearancefromcombustiblematerials
to vent pipe.
5. Vertical venting — See Figure 6.Followventmanufacturer’s
instructionsforventingthroughroof.
• Vent pipe must extend through roof ashing, jacket or
thimble.
• Vent may pass through oor, inside wall or concealed
space when installed according to vent manufacturer’s
instructions.
Sidewall venting — See Figures 7 and 8. Vent must terminate
atleastonefootaboveanticipatedsnowline.Vent mustbe
terminated only with:
• Elbowwithintegralscreen.
• Elbowandterminationcouplingwithscreen(notavailable
forStaR-34).
6. Donotsealventpipe(slipconnectorforSaf-TVent)toinside
or outside plate.
7. Ifpassingthroughnoncombustiblewall,provideholediam-
eterlargeenoughtoinserttheventpipe(slipconnectorfor
Saf-TVent).
8. Installhorizontaldrainteeascloseaspossibletoboiler,in
first horizontal run. See Figure 7.
9. Do not exceed the maximum vent system length given in
Table 4, page 9.
 Condensatedrainline—useonlysiliconetubing
ratedforatleast400°Ffortherst18”ofconden-
sate drain line, then other non-metallic tubing may
beused.Usinganyothermaterialcouldcauseue
gasleakage,potentiallyresultinginseverepersonal
injury, death or substantial property damage.
On some installations, the condensate drain fitting
may be omitted, provided:
• Ventmanufacturershowsthisoptionintheirinstruc-
tions.
• Ventisslopedtowardterminationasshownindotted
lines in Figure 7.
• Theventisinstalledperboilermanufacturer’sand
ventmanufacturer’sinstructions.
Condensatedrippagefromsuchventsmayaccumulateonthe
groundbelow.Considertrafcintheareatoavoidhazarddueto
ice accumulation.
Installing direct exhaust vent and termination
3 Vent installation continued
Figure 6 Vertical direct exhaust installation Figure 7 Direct exhaust through side wall
12 Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
 Usinganyterminationotherthanoneofthoseshown
could cause nuisance outages and loss of heat,
resulting in substantial property damage.
Direct exhaust venting continued
Figure 8 Sidewall vent termination options and
installation requirements
3 Vent installation continued
13
Part Number 550-142-785/0812
Table 6 Water pipe size (based on 20 °F rise)
General
Boiler
model
number
To
system From
system
GWI-047 ¾” ¾”
GWI-063 1” 1”
GWI-095 1” 1”
GWI-127 1” 1”
GWI-158 1 ¼” 1 ¼”
GWI-190 1 ¼” 1 ¼”
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
IfinstallationistocomplywithASMEorCanadianrequirements,
anadditionalhightemperaturelimitisneeded.Installcontrolin
supply piping between boiler and isolation valve. Set second
controltominimum20°Fabovesetpointofrstcontrol.Maximum
allowablesetpointis240°F.Seepage 24 and 25forwiring.
Alowwatercutoffdeviceisrequiredwhenboilerisinstalledabove
radiation level or by certain state or local codes or insurance
companies.Uselowwatercutoffdesignedforwaterinstallations.
Electrodeprobe-typeisrecommended. Purchaseandinstallin
tee in supply piping above boiler.
Usebackowcheckvalveincoldwatersupplyifrequiredby
local codes.
See Figure 9(diaphragm-typeorbladder-typeexpansiontank)
orFigure10(closed-typeexpansiontank)onpage 14, and Table
6, for near-boiler and single-zone systems designed for return
wateratleast130°F.
See page 13formultiple-zonepiping.
See page 14forboilersusedwithrefrigerationsystems.
Near-boiler piping
Relief valve
Installreliefvalveverticallyin¾”tappingonsideofboiler.See
thetagattachedtothereliefvalveformanufacturer’sinstructions.
To avoid water damage or scalding due to valve
operation, discharge line must be connected to re-
liefvalveoutletandruntoasafeplaceofdisposal.
Terminate the discharge line to eliminate possibility
ofsevereburnsshouldthevalvedischarge.
• Dischargelinemustbeasshortaspossibleandbe
the same size as the valve discharge connection
throughout its entire length.
• Dischargelinemustpitchdownwardfromthevalve
and terminate at least 6” above the floor drain where
any discharge will be clearly visible.
• Thedischargelineshallterminateplain,notthread-
ed,withamaterialserviceablefortemperaturesof
375°Forgreater.
• Donotpipethedischargetoanyplacewherefreez-
ing could occur.
• Noshutoffvalveshallbeinstalledbetweentherelief
valve and boiler, or in the discharge line. Do not plug
or place any obstruction in the discharge line.
• Failuretocomplywiththeaboveguidelinescould
resultinfailureofthereliefvalvetooperate,result-
inginpossibilityofseverepersonalinjury,deathor
substantial property damage.
• Testtheoperationofthevalveafterllingandpres-
surizingsystembyliftingthelever.Makesurethe
valvedischargesfreely.Ifthevalvefailstooperate
correctly,replaceitwithanewreliefvalve.
Circulator
The circulator is shipped loose (wiring pre-attached to boiler)
to allow you to locate it either in the return or supply piping, as
desired. See page 14foratypicalinstallation.Pipetheexpansion
tanktothesuctionsideofthecirculatorwheneverpossible.Install
anairseparatorinthesupplypiping.Connecttheexpansiontank
totheairseparatoronlyiftheseparatorisonthesuctionsideof
thecirculator.Alwaysinstallthesystemllconnectionatthesame
pointastheexpansiontankconnectiontothesystem.Figures 4
and 5 show typical near-boiler piping connections.
Expansion tank
Diaphragm- or bladder-type expansion tank — Figure 9,
page 14
1. Ensure expansion tank size will handle boiler and system
watervolumeandtemperature.Tankmustbelocatedinboiler
returnpipingasclosetoboileraspossible,beforeinletside
ofcirculator.Seetankmanufacturer’sinstructionsfordetails.
2. Installanautomaticairventasshown.
Closed-type expansion tank — Figure 10, page 14
1. Ensureexpansiontanksizewillhandleboilerandsystemwater
volumeandtemperature.Seetankmanufacturer’sinstructions
fordetails.
2. Connecttankto½”NPTtappinglocatedbehindsupplyoutlet,
using ½” NPT piping. Pitch any horizontal piping up towards
tank1inchper5feetofpiping.
 Undersizedexpansiontanks cause system water
tobelostfromreliefvalveandmakeupwatertobe
addedthroughllvalve.Eventualsectionfailurecan
result.
Water piping — multiple zone systems
Installsystempipingusingeithercirculatorzoningorzonevalve
zoning.Installexpansiontankonsuctionsideofsystempump.
Alwaysconnectllline only at the expansiontank—neverat
another point in the system.
DO NOT connect directly from 3-wire zone
valves to the T-T terminals on the boiler.
When using 3-wire zone valves, install an isolation
relay.Connectthezonevalveendswitchwiresto
theisolationrelaycoil.Connecttheisolationrelay
contact across the boiler T-T terminals. Failure to
comply can result in damage to boiler components
or cause unreliable operation, resulting in severe
property damage.
4 Install water piping4 Install water piping
14 Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Water piping — refrigeration systems
Prevent chilled water from entering boiler
Installboilersothatchilledmediumispipedinparallelwiththe
heatingboiler.Useappropriatevalvestopreventchilledmedium
from entering boiler.  See Figure 11 for typical installation of
balancingvalveandcheckvalve.
Figure 9 Diaphragm- or bladder-type expansion tank:
Piping to single-zone system using
diaphragm-type or bladder-type expansion
tank. See Table 6, page 13, for piping sizes.
Figure 10 Closed-type expansion tank: Piping to single-
zone system using closed-type expansion
tank. See Table 6, page 13, for piping sizes.
Figure 11 Piping refrigeration systems
 Installboilersothatchilledmediumispipedinpar-
allelwithheatingboiler.Useappropriatevalvesto
preventchilledmediumfromenteringboiler.Consult
AHRIInstallationandPipingGuides.
If boiler is connected to heating coils located in
air handling units where they can be exposed to
refrigeratedair,useowcontrolvalvesorotherau-
tomatic means to prevent gravity circulation during
coolingcycle.Circulationofcoldwaterthroughthe
boilercouldresultindamagetotheheatexchanger,
causing possible severe personal injury, death or
substantial property damage.
 Ifsystemincludesradiantheatingcircuits,provide
piping and controls to regulate the temperature sup-
plying the radiant circuits. Failure to comply could
result in substantial property damage.
 UseFigure9orFigure10onlyforsystemsdesigned
forreturn waterat least130°F.Forsystemswith
low return water temperature, such as converted
gravity systems and radiant heating systems, install
bypasspiping(seepage 15)toprotectboileragainst
condensation. Failure to prevent low return water
temperaturetotheboilercouldcausecorrosionof
the boiler sections or burners, resulting in severe
personal injury, death or substantial property dam-
age.
4 Install water piping continued
15
Part Number 550-142-785/0812
4 Install water piping continued
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Figure 12 System bypass piping in boiler loop with
separate system circulator, using primary/
secondary piping
Figure 13 Boiler bypass piping — use only for high
water content systems — DO NOT use for
radiant panel systems
Near-boiler piping continued
 Installallcomponentsspeciedaboveandadjustvalvesasdescribedtopreventlowtemperatureintheboiler.Failureto
preventlowwatertemperatureintheboilercouldcausecorrosionoftheboilersectionsorburners,resultinginsevere
personal injury, death or substantial property damage.
System bypass method
1. Apply bypass piping of Figure 12 to high water content
systems,radiantpanelsystemsoranysystemthatislikely
to operate with low return water temperature for extended
periods.
2. Thebypassarrangementshownprotectstheboilerfromdam-
age caused by condensate corrosion due to low return water
temperatureandprotectslowtemperaturesystemsfromtoo
high a supply temperature.
3. Adjustthebypassvalvesasindicatedbelow.
Adjust Bypass valves 1 and 2 as follows:
1. Startwithvalve2fullyclosed,valve1fullyopen.
2. Slowlyopenvalve2whileclosingvalve1.Adjustthevalves
untiltheboilerpressure/temperaturegaugereads160°For
higher.Asyouopenthevalves,pauselongenoughtoallow
temperaturestoleveloff.Ittakesawhilefortheboilerwater
temperature to rise as the flow changes.
3. Bypass valve 2 allows hot boiler outlet water to blend with
colder return water, raising the supply temperature to the boiler.
Bypass valve 1 balances the pressure drop through valve 2.
4. Thepurposeofthispipingistoraisethereturnwatertem-
peraturetotheboilerenoughtopreventcondensationofue
gases.
Boiler bypass method
1. ApplybypasspipingofFigure 13 to high water content sys-
tems, such as converted gravity systems.
2. Thebypassarrangementshownprotectstheboilerfromdam-
age caused by condensate corrosion due to low return water
temperature.Thismethoddoesnotprovideprotectionfrom
high temperature water being supplied to the system.
3. DO NOT apply this piping to radiant panel systems.
4. Adjustthebypassvalvesasindicatedbelow.
Adjust Bypass valves 1 and 2 as follows:
1. Startwithvalve1fullyclosed,valve2fullyopen.
2. Slowlyopenvalve1whileclosingvalve2.Adjustthevalves
until the boiler pressure/temperature gauge reads approxi-
mately60°Fhigherthanthesystemtemperaturegauge.As
you open the valves, pause long enough to allow temperatures
toleveloff.Ittakesawhilefortheboilerwatertemperatureto
rise as the flow changes.
3. Bypass valve 1 controls system flow rate. Bypass valve 2
controls flow through the boiler.
4. Thepurposeofthispipingistocause ahighenoughtem-
perature rise in the boiler that the average temperature will
bewarmenoughtopreventcondensationofuegases.
16 Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Figure 14 Gas supply pipingTable 7 Pipe capacity for 0.60 specic gravity natural gas
Connecting gas supply piping to boiler
1. RemovejacketfrontpanelandseeFigure 14 to pipe gas to
boiler.
a. Installdriplegatinletofgasconnectiontoboiler.Where
localutilityrequiresdriplegtobeextendedtotheoor,
useappropriatelengthofnipplebetweencapandtee.
b. Installgroundjointunionforservicing,whenrequired.
c. Installmanualshutoffvalveingassupplypipingoutside
boilerjacketwhenrequiredbylocalcodesorutilityrequire-
ments.
d. InCanada—Whenusingmanualmainshutoffvalve,it
must be identified by the installer.
2. Support piping with hangers, not by boiler or its accessories.
3. Purgeallairfromgassupplypiping.
4. Beforeplacingboiler in operation,checkboiler and its gas
connectionforleaks.
a. Close manual main shutoff valve during any pressure
testing at less than 13” w.c.
b. Disconnectboilerandgasvalvefromgassupplypiping
during any pressure testing greater than 13” w.c.
 Donotcheckforgasleakswithanopename—Use
bubbletest.Failuretousebubbletestorcheckfor
gasleakscancauseseverepersonalinjury,death
or substantial property damage.
5. Usepipedopecompatiblewithpropanegases.Applysparingly
onlytomalethreadsofpipejointssothatpipedopedoesnot
blockgasow.
5 Install gas piping
Failure to apply pipe dope as described in this
manual can result in severe personal injury, death
or substantial property damage.
Natural Gas:
1. SeeTable7forpipelengthanddiameter.Baseonratedboiler
input(divideby1,000toobtaincubicfeetperhour).Table 7
isonlyforgaswithspecicgravity0.60,withapressuredrop
throughthegaspipingof0.30”w.c.Foradditionalgaspipe
sizinginformation,seeANSIZ223.1(B149.1orB149.2for
Canadianinstallations).
2. Inletpressurerequiredatgasvalveinlet:
• Maximum:13”w.c.
• Minimum:5”w.c.
• Manifoldgaspressure:3.5”w.c.
3. Install100%lockupgaspressureregulatorinsupplylineif
inletpressureexceeds13”w.c.Adjustfor13”w.c.maximum.
Propane Gas:
1. Contactgassuppliertosizepipes,tanksand100%lockup
gas pressure regulator.
2. Adjustpropanesupplyregulatorprovidedbygassupplierfor
13”w.c.maximumpressure.
3. Inletpressurerequiredatgasvalveinlet:
• Maximum:13”w.c.
• Minimum:11”w.c.
• Manifoldgaspressure:10”w.c.
Gas pipe
length
(feet)
Capacity of pipe for pipe size of:
(Capacity in cubic feet gas per hour)
½” ¾” 1” 1¼” 1½”
10 132 278 520 1050 1600
20 92 190 350 730 1100
30 73 152 285 590 860
40 63 130 245 500 760
50 56 115 215 440 670
75 45 93 175 360 545
100 38 79 150 305 460
150 31 64 120 250 380
17
Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Foryoursafety,turnoffelectricalpowersupplyat
serviceentrancepanelbeforemakinganyelectrical
connectionstoavoidpossibleelectricshockhazard.
Failure to do so can cause severe personal injury
or death.
 WiringmustbeN.E.C.Class1.
If rollout thermal fuse element wire as supplied
withboilermustbereplaced,type200°Cwireor
equivalentmustbeused.Ifotheroriginalwiringas
supplied with boiler must be replaced, use only type
105°Cwireorequivalent.
 Boilermustbeelectricallygroundedasrequiredby
NationalElectricalCodeANSI/NFPA70-latestedition.
Electrical installation must comply with:
1. NationalElectricalCodeandanyothernational,state,provin-
cial or local codes or regulations.
2. InCanada,CSAC22.1CanadianElectricalCodePart1,and
any local codes.
Wiring connections
Boiler is shipped with controls completely wired. See wiring dia-
gram on page 24 and 25fordetails.Circulatorisshippedloose,
butwiringharnessispre-attachedtotheboiler.Connectwiresin
circulatorjunctionbox.
Thermostat
1. Connectthermostatasshownonwiringdiagramonboiler.
2. Installoninsidewallawayfrominuencesofdrafts,hotorcold
waterpipes,lightingxtures,television,sunraysorreplaces.
3. If thermostat has a heat anticipator, set heat anticipator in
thermostattomatchpowerrequirementsofequipmentcon-
nectedtoit.Ifconnecteddirectlytoboiler,seeWiringdiagrams,
6 Field wiring
page 24 and 25,foranticipatorsetting.Forotherdevices,see
manufacturer’sspecications.Wiringdiagramonboilergives
settingforcontrolmoduleandgasvalve.Alsoseeinstructions
with thermostat.
DHW (if used)
ConnectDHWaquastatasshowninwiringbelow.Economy
functionisn’tutilizedwithDHWinput.
R & C Connections (if used)
24Vacleadsshouldbeusedforpowerstealingthermostatsonly!
Junction box (furnished)
1. Connect120VACpowerwiring(Figure 15).
2. Fuseddisconnectorserviceswitch(15amp.recommended)
maybemountedonthisbox.Forthoseinstallationswithlocal
codeswhichprohibitinstallationoffuseddisconnectorservice
switchonboiler,installa2x4coverplateontheboilerjunction
boxandmounttheserviceswitchremotelyasrequiredbythe
code.
Wiring multiple zones
Seezonevalvemanufacturer’sliteratureforwiringandapplication.
Aseparatetransformerisrequiredtopowerzonevalves.Zoning
withcirculatorsrequiresarelayforeachcirculator.
DO NOT connect directly from 3-wire zone
valves to the T-T terminals on the boiler.
When using 3-wire zone valves, install an isolation
relay.Connectthezonevalveendswitchwiresto
theisolationrelaycoil.Connecttheisolationrelay
contact across the boiler T-T terminals. Failure to
comply can result in damage to boiler components
or cause unreliable operation, resulting in severe
property damage.
Figure 15 Field wiring connections — service switch, DHW (if used) and thermostat (or end switch) provided by installer
18 Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Check for gas leaks
 Beforestartingtheboiler,andduringinitialopera-
tion,smellneartheoorandaroundtheboilerfor
gas odorant or any unusual odor. Do not proceed
withstart-upifthereisanyindicationofagasleak.
Repairanyleakatonce.
 Propaneboilersonly—Yourpropanesuppliermixes
anodorantwiththepropanetomakeitspresence
detectable.Insomeinstances,theodorantcanfade
and the gas may no longer have an odor.
• Propanegascanaccumulateatoorlevel.Smell
neartheoorforthegasodorantoranyunusual
odor.Ifyoususpectaleak,donotattempttolight
the pilot.
• Usecautionwhenattemptingtolightthepropane
pilot.Thisshouldbedoneby aqualiedservice
technician,particularlyifpilotoutagesarecommon.
• Periodicallychecktheodorantlevelofyourgas.
• Inspectboilerandsystematleastyearlytomake
sureallgaspipingisleak-tight.
• Consultyourpropanesupplierregardinginstallation
ofagasleakdetector.Therearesomeproductson
themarketintendedforthispurpose.Y
oursupplier
may be able to suggest an appropriate device.
Determine if water treatment is needed
Do not use petroleum-based cleaning or sealing
compounds in boiler system. Severe damage to
boiler will occur, resulting in substantial property
damage.
 Eliminateallsystemleaks.Continualfreshmakeup
waterwillreduceboilerlife.Mineralscanbuildup
insections,reducingheattransfer,overheatingcast
iron,andcausingsectionfailure.
Verify water chemistry
Consultlocalwatertreatmentcompaniesforunusuallyhardwater
areas(above7grainshardness)orlowpHwaterconditions(below
7.0).BoilerwaterpHof7.0to8.5isrecommended.
Freeze protection (when used)
Useantifreezemadeespeciallyforhydronicsystems.Inhibited
propylene glycol is recommended.
Do not use ethylene glycol, automotive or undiluted
antifreeze. Severe personal injury or death can
result.
1. Determine antifreeze quantityaccordingtosystemwater
content. Boiler water content is listed on page 47. Remember
toincludeexpansiontankwatercontent.
2. Followantifreezemanufacturer’sinstructions.
3. A50%solutionofpropyleneglycol/waterprovidesmaximum
protectiontoabout-30°F.
4. Localcodesmayrequirebackowpreventeroractualdiscon-
nectfromcitywatersupply.
5. Whenusingantifreezeinasystemwithautomaticll,installa
watermetertomonitorwatermakeup.Glycolwillleakbefore
thewaterbeginstoleak,causingglycolleveltodrop.Added
waterwilldilutetheantifreeze,reducingthefreezeprotection
level.
Preparation
Fill the system with water
1. Closemanualandautomaticairventsandboilerdraincock.
2. Fill to correct system pressure. Correct pressure will vary
witheachapplication.T
ypical coldwater llpressurefor a
residential system is 12 psi.
3. Purgeairfromsystem:
a. Connectahosetopurgevalveorvalves,ifinstalled.Route
hose to an area where water can drain and be seen.
b. Close the boiler or system isolation valve between the
purge valve and fill connection to the system.
c. Closezoneisolationvalves.
d. Openquick-llvalveoncoldwatermakeupline.
e. Open purge valve.
f. Onezoneatatime,opentheisolationvalves.Allowwater
to run through the zone, pushing out the air. Run until no
noticeable air ow is present. Close the zone isolation
valvesandproceedwiththenextzone.Followthisproce-
dure until all zones are purged.
g. Closethequick-llwatervalveandpurgevalveandremove
the hose. Open all isolation valves. Watch that system
pressure rises to correct cold-fill pressure.
h. Afterthesystemhasoperatedforawhile,eliminateany
residual air by using the manual air vents located through-
out the system.
i. Ifpurgevalvesarenotinstalledinsystem,openmanualair
vents in system one at a time, beginning with lowest floor.
Closeventwhenwatersquirtsout.Repeatwithremaining
vents.
4. Open automaticairvent (diaphragm-type orbladder-type
expansiontanksystemsonly)oneturn.
5. Open other vents:
a. Starting on the lowest floor, open air vents one at a time
untilwatersquirtsout.
b. Repeat with remaining vents.
6. Refill to correct pressure.
Inspect system water piping
Afterllingthe boiler and systemwithwater, inspectallpiping
throughoutthesystemfor leaks. Iffound, repairimmediately.
Repeatthisinspectionaftertheboilerhasbeenstartedandthe
system has heated up.
 Leaksmustberepairedatonce.Failuretodosocan
damage the boiler, resulting in substantial property
damage.
Do not use petroleum-based cleaning or sealing
compounds in boiler system. Severe damage to
boiler will occur, resulting in substantial property
damage.
Inspect base insulation
Checktomakesureinsulationissecureagainstallfoursidesof
thebase.Ifinsulationisdamagedordisplaced,donotoperate
boiler. Replace or reposition insulation.
Failure to replace damaged insulation or reposition
insulation can result in a fire hazard, causing severe
personal injury, death or substantial property dam-
age.
The boiler contains ceramic fiber and fiberglass
materials.Usecarewhenhandlingthesematerials
perinstructionsonpage48ofthismanual.Failure
to comply could result in severe personal injury.
7 Start-up
19
Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Operate boiler
DO NOT proceed with boiler operation unless boiler
and system have been filled with water and all in-
structionsandproceduresofpreviousmanualsec-
tions have been completed. Failure to do so could
result in severe personal injury, death or substantial
propertydamage.Beforestartingtheboiler...
• ReadmanualSections 9 and 10andthe“Operating
instructions”, page 26.
• Verifytheboilerandsystemarefullofwater.
• VerifytheStart-up“Preparation”proceduresofthis
section have been completed.
Adjust boiler control settings
BOILER OPERATING TEMPERATURE
With power turned on, control module receives a signal from
the temperature sensor and displays boiler temperature. The
control knob labeled BOILER TEMP is used to adjust the
operating temperature setpoint, turning clockwise to increase
temperature setting and counterclockwise to decrease. When the
knob is turned to adjust temperature the display will brighten to
indicate adjustment mode. After temperature is set to desired
value, display will dim after approximately 5 seconds to indicate
measurement mode.
ADJUST BOILER OPERATING TEMPERATURE TO
DESIRED SETPOINT
BOILER ECONOMY SETTING
To comply with Department of Energy regulations, the control
module circulates available hot water before turning on the boiler
to attempt to satisfy a call for heat. While attempting to satisfy
the heat demand, the control module also monitors the boiler
temperature changes via the temperature sensor and determines
whether or not the available hot water will satisfy the demand,
adjusting the time delay to turn on the boiler until it determines
that additional heat will be needed. The knob labeled ECONOMY
ADJUST provides an adjustment between maximize (MAX) and
minimize (MIN) the delay. The maximum (MAX) adjustment
position should be used to maximize energy savings. Turning the
knob counterclockwise decreases the delay time and should only
be used in the event that the heated space becomes uncomfortable.
ADJUST ECONOMY TO DESIRED POSITION
(MAX IS THE PREFERRED SETTING)
IMPORTANT
In accordance with Section 325 (f) (3) of the Energy Policy
and Conservation Act, this boiler is equipped with a feature
that saves energy by reducing the boiler water temperature
as the heating load decreases. This feature is equipped with
an override which is provided primarily to permit the use of
an external energy management system that serves the same
function.
7 Start-up continued
THIS OVERRIDE MUST NOT BE USED UNLESS AT LEAST
ONE OF THE FOLLOWING CONDITIONS IS TRUE:
• An external energy management system is installed that
reduces the boiler water temperature as the heating load
decreases.
• This boiler is part of a modular or multiple boiler system
having a total input of 300,000 BTU/hr or greater.
• This boiler is equipped with a tankless coil.
Start the boiler
Followthe“Operatinginstructions”,page 26.
Ifboilerfailstostart,see“Ifboilerdoesn’tstart...Checkfor:”
on this page.
Check system and boiler
 Eliminateallsystemleaks.Continualfreshmakeup
waterwillreduceboilerlife.Mineralscanbuildup
insections,reducingheattransfer,overheatingcast
iron,andcausingsectionfailure.
 Ifyoudiscoverevidenceofanygasleak,shutdown
theboileratonce.Findtheleaksourcewithbubble
test and repair immediately. Do not start boiler again
until corrected. Failure to comply could result in se-
vere personal injury, death or substantial property
damage.
Do not use petroleum-based cleaning or sealing
compounds in boiler system. Severe damage to
boiler will occur, resulting in substantial property
damage.
1. Checksystempipingforleaks.Iffound,shutdownboilerand
repair immediately.
2. Ventairfromsystemusingmanualvents.Airinthesystemwill
interferewithcirculationandcauseheatdistributionproblems
and noise.
3. Inspectventsystemthoroughlyforsignsofdeteriorationfrom
corrosion,physicaldamageorsagging.Verifythatmasonry
chimney liners are in good condition, with no obstructions,
and there are no openings into the chimney.
4. Checkaroundtheboilerforgasodorfollowingtheprocedure
ofpage 16ofthismanual.
5. Verifyoperationusingproceduresbelow.Perform“Checkout
procedure” on pages 20 and 21andllinthe“Installationand
service certificate”.
If boiler doesn’t start . . . Check for:
1. Looseconnections,blownfuseorserviceswitchoff?
2. Highlimitswitchsetbelowboilerwatertemperature?
3. Thermostatsetbelowroomtemperature?
4. Gasnotturnedonatmeterorboiler?
5. Incominggaspressurelessthan:
 5”w.c.fornaturalgas?11”w.c.forpropanegas?
6. Ifnoneoftheabovecorrectstheproblem,see“Troubleshoot-
ing”, page 31ofthismanual.
20 Part Number 550-142-785/0812
GWI
Series 2 Gas-Fired Water Boilers – Boiler Manual
Boilerandheatdistributionunitslledwithwater?
Automaticairvent,ifused,openonefullturn?
Airpurgedfromsystem?
Airpurgedfromgaspiping?Pipingcheckedforleaks?
Correctly-sized manifold orices installed? See Table 3,
page 6tochecksizeandfueltype.
Correctly sized manifold orices must be used.
Failure to do so will cause severe personal injury,
death or substantial property damage.
Followed“Operatinginstructions”onboilerorinmanual,page
26forproperstart-up?
Properburnerameobserved?See“Verifyoperation”,manual
Section 7.
Test temperature limit — While burners are operating, turn
BoilerTempadjustmentknobcounterclockwiseuntildisplay
reading is below actual boiler water temperature. Burners
should go off while circulator continues to operate.Turn
BoilerTempadjustmentknobclockwiseuntildisplayread-
ingisaboveboilerwatertemperatureandignitionsequence
should resume.
Test additional eld-installed controls — If boiler hasalow
water cutoff, additional high limit or other controls, test for
operation as outlined by manufacturer. Burners should be
operatingandshouldgooffwhencontrolsaretested.When
controls are restored, burners should reignite.
Testignitionsystemsafetydevice:
a. Connectmanometertooutletsideofgasvalve.Startboiler,
allowingfornormalstart-upcycletooccurandmainburn-
erstoignite.Withmainburnerson,manuallyshutoffgas
supplyatmanualmainshutoffgasvalve.Burnersshould
gooff.Openmanualmainshutoffgasvalve.Manometer
should confirm there is no gas flow. Pilot will relight, flame
sensing element will sense pilot flame and main burners
reignite.
Setlimitcontrol(s)tosystemtemperaturerequirements.Adjust
balancing valves and controls to provide design temperature
to system.
SetEconomymode,fullyclockwise.
For multiple zones, adjust flow so it is about the same in each zone.
Verifythermostatheatanticipator(ifavailable)setproperly?
See wiring diagram label on boiler or in manual, page 24 and
25.
Cycleboilerwiththermostat—Raisetohighestsettingand
verify boiler goes through normal start-up cycle. Lower to
lowestsettingandverifyboilergoesoff.
CycleDHWAquastatifused.
Measurenaturalgasinput:
a. Operate boiler 10 minutes.
b. Turnoffotherappliances.
c. Atnaturalgasmeter,measuretime(inseconds)required
touseonecubicfootofgas.
d. Calculategasinput:
3600 x 1000
number of seconds from step c
= Btuh
e. Btuhcalculatedshouldapproximateinputratingonboiler
8 Checkout procedure
Check burner flame — Pilot burner
Proper pilot flame (see Figure 16):
1. Blue flame.
2. Innerconeengulngpilotamesensor.
3. Pilot flame sensor glowing cherry red.
Improper pilot flame:
1. Overred — Large ame lifting or blowing past pilot ame
sensor.
2. Underred—Smallame.Innerconenotengulngpilotame
sensor.
3. Lackofprimaryair—Yellowametip.
Figure 17 Typical main burner ame
Verify operation
Figure 16 Typical pilot burner ame
4. Incorrectlyheatedpilotamesensor.
Check burner flames — Main burner
Proper main burner flame (see Figure 17):
1. Yellow-orangestreaksmayappear(causedbydust).
Improper main burner flame:
1. Overred—Largeames.
2. Underred—Smallames.
3. Lackofprimaryair—Yellowtippingonames(sootingwill
occur).
7 Start-up continued
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Williamson GWI-127 User manual

Category
Water heaters & boilers
Type
User manual
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