ICP GWA 245 User manual

Part Number 670 01 1001 00
GWA
This manual must only be used by a qualified heating installer/service technician. Failure to comply could result in
severepersonalinjury,death orsubstantial property damage.
Whencallingorwritingabouttheboiler—Pleasehave: • boilermodelnumberfromtheboilerratinglabel and • CP number
fromtheboiler jacket.YoumaylisttheCP numberin the spaceprovidedonthe“Installationandservicecertificate”foundon
page18.
Contents Page
1 Prepareboilerlocation ........................................................2
2 Prepareboiler .....................................................................6
3 Installwaterpiping ............................................................10
4 Installgas piping ...............................................................13
5 Fieldwiring .......................................................................14
6 Start-up ............................................................................15
7 Checkoutprocedure .........................................................18
8 Sequenceof operation —standing pilotboilers.................19
9 Lightinginstructions—GWAstandingpilot boilers ...........20
10 Serviceandmaintenance .................................................22
11 Troubleshooting ................................................................27
12 Replacementparts ...........................................................29
13 Dimensions ......................................................................34
14 Ratings .............................................................................35
Boiler Manual
Gas-Fired Water Boilers
Hazardsthatwillorcancauseminorpersonalinjury
orpropertydamage.
Special instructions on installation, operation or
maintenance that are important but not related to
personalinjuryor property damage.
INSTALLER —Read all instructions before
installing.Read page 2 first.Followallinstructions
inproperorder to preventpersonalinjury or death.
•Considerpipingand installation whendetermining
boilerlocation.
•Any claims for damage or shortage in shipment
mustbefiledimmediatelyagainstthetransportation
companyby theconsignee.
USER —Please read the following. Failure to
complycouldresultinseverepersonalinjury,death
orsubstantial property damage.
•This manual is for use only by your qualified
heating installer/service technician.
•Pleaseseethe User’sInformation Manualforyour
reference.
•Have the boiler serviced by a qualified service
technician,at leastannually.
Hazards that will cause severe personal injury,
deathor substantial propertydamage.
Hazards that can cause severe personal injury,
deathor substantial propertydamage.
Hazard definitions
GWA Gas-Fired Water Boilers – Boiler Manual
36 Part Number 670 01 1001 00

GWA Gas-Fired Water Boilers –Boiler Manual
2Part Number 670 01 1001 00
Installations must follow these codes:
•Local, state, provincial, and national codes, laws, regulations
andordinances.
•NationalFuel Gas Code,ANSI Z223.1–latestedition.
•Standard for Controls and Safety Devices for Automatically
FiredBoilers, ANSI/ASMECSD-1, whenrequired.
•NationalElectrical Code.
•For Canada only: B149.1 or B149.2 Installation Code, CSA
C22.1Canadian Electrical Code Part1 and any local codes.
Certification
TheGWAboilergas manifoldand controlsmet safe
lighting and other performance criteria when boiler
underwent tests specified in ANSI Z21.13–latest
edition.
Before locating the boiler:
❏Check for nearby connection to:
•Systemwater piping
•Venting connections
•Gassupply piping
•Electricalpower
❏Checkareaaroundboiler.Remove anycombustiblematerials,
gasolineandother flammable liquids.
Failure to keep boiler area clear and free of
combustiblematerials,gasolineandotherflammable
liquids and vapors can result in severe personal
injury,deathor substantialpropertydamage.
❏Boilermustbeinstalledso that gascontrolsystemcomponents
are protected from dripping or spraying water or rain during
operationor 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
fromhard waterdeposits.
2. Incorrectly-sized expansion tank.
3. Lackof antifreezeinboilerwatercausing system andboiler
tofreeze andleak.
Codes & checklist
Failure to adhere to the guidelines below can
result in severe personal injury, death or
substantialpropertydamage.
When servicing boiler —
1. To avoid electric shock, disconnect electrical supply
beforeperformingmaintenance.
2. To avoid severe burns, allow boiler to cool before
performingmaintenance.
Boiler operation —
3. Donot block flowof combustionor ventilationairto boiler.
4. Shouldoverheating occurorgassupply fail toshutoff, do
not turn off or disconnect electrical supply to circulator.
Instead, shut off the gas supply at a location external to
theappliance.
5. Do not use this boiler if any part has been under water.
Immediatelycall aqualified servicetechnician toinspect
the boiler and to replace any part of the control system
andany gas control thathas been underwater.
Boiler water —
6. DO NOT use petroleum-based cleaning or sealing
compoundsinboiler system.Watersealdeteriorationwill
occur,causing leakage betweenboilersections,circulator
flanges, diaphragm tanks or other system components.
Thiscan resultin substantialproperty damage.
7. DO NOT use "homemade cures" or "boiler patent
medicines".Serious damage to boiler, personnel and/or
property may result.
8. Continualfreshmakeupwaterwillreduceboilerlife.Mineral
buildupin sectionsreduces heattransfer, overheatscast
iron, and causes section failure. Addition of oxygen and
othergases can causeinternal 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 —
Allglycolisflammable when exposedtohigh temperatures. If
glycolis allowedto accumulate in or aroundthe boileror any
other potential ignition source, a fire can develop.In order to
preventpotential severe personal injury, death orsubstantial
propertydamagefrom fire and/orstructural damage:
•Never store glycol of any kind near the boiler or any
potentialignitionsource.
•Monitor and inspect the system and boiler regularly for
leakage.Repairanyleaksimmediatelyto preventpossible
accumulationof glycol.
•Neveruseautomotive antifreezeorethylene glycol inthe
system. Using these glycols can lead to hazardous
leakageof glycolin theboiler system.
1 Prepare boiler locationRead this first!
GWA Gas-Fired Water Boilers –Boiler Manual
35Part Number 670 01 1001 00
InstallGWAboilersforresidentialradiant panelsystems,convertedgravity
heatingsystemsorother low water temperatureapplicationsperinstructions
inthis manual toavoid damagedue to condensation.
GWA boilers are CSA design certified for installation on combustible
flooring.
GWA boilers are ASME rated for 50 psig working pressure.
14 Ratings
DOE
1. Based on standard test procedures prescribed by the United States Department of
Energy.
2. Net I=B=R ratings are based on net installed radiation of sufficient quantity for the
requirementsof the buildingandnothing need beadded fornormalpiping and pickup.
Ratingsare basedon apiping andpickup allowanceof 1.15.An additionalallowance
shouldbe madefor unusual pipingand pickuploads.
3. See information at rightfor model number suffixes. Lettersshown are model number
suffixes. An “N”after the model number designates natural gas. The letter after the
“N”designates the pilot ignition system —“S”for standing pilot or “I”for spark-
ignited pilot. For example, a suffix “NS”means a natural standing pilot boiler.
4. Contact your International Comfort Products dealer regarding information and parts
for high altitude applications.
Boiler
model
number
0–2,000 feet altitude 2,000–4,500 feet altitude
(Canada) Net I=B=R
ratings
(Btuh)
Boiler
water
content
(gallons)
DOE
Seasonal
efficiency
(% A.F.U.E)
Chimney
and
breeching
size
Input
(Btuh) DOE Heating Capacity (Output) (Btuh) Input (Btuh) Output (Btuh) NS NI
(Note 3) (Note 1) (Note 4) (Note 2) (Note 3)
GWA052 52,000 43,000 46,800 37,400 37,000 1.5 80.2 83.0 4"I.D. x 20’
GWA070 70,000 58,000 63,000 50,400 50,000 1.5 80.1 82.2 4"I.D. x 20’
GWA105 105,000 88,000 94,500 75,600 77,000 2.1 80.4 82.9 5"I.D. x 20’
GWA140 140,000 117,000 126,000 100,800 102,000 2.7 80.4 82.5 6"I.D. x 20’
GWA175 175,000 145,000 157,500 126,000 126,000 3.3 80.5 82.2 6"I.D. x 20’
GWA210 210,000 175,000 189,000 151,200 151,000 3.8 80.5 81.8 7"I.D. x 20’
GWA245 245,000 202,000 220,500 176,400 176,000 4.4 80.5 81.4 7"I.D. x 20’

GWA Gas-Fired Water Boilers –Boiler Manual
3Part Number 670 01 1001 00
Service clearances
1. Provide minimum clearances for cleaning and servicing the
boiler and for access to controls and components as listed in
thetablebelow:
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
movedfor servicing.
Figure 1 Minimum clearances
Clearances
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"
Flooring and foundation
Flooring
TheGWAboilerisapprovedforinstallationoncombustible flooring,
butmust neverbe installed on carpeting.
Donotinstallboiler oncarpetingevenif foundation is
used.Fire canresult,causing severepersonal injury,
deathor substantial propertydamage.
Foundation
1. Provide a solid brick or minimum 2-inch thick concrete
foundationpad ifany of the following istrue:
•floorcan become flooded.
•theboiler mounting areais notlevel.
2. SeeTable1 forminimumfoundationdimensions.
Residential garage installation
Takethe followingspecialprecautions wheninstalling theboiler in
aresidential garage.If theboiler is located in a residential garage,
perANSI Z223.1, paragraph5.1.9:
•Mountthe boiler aminimum of18 inches abovethe floorof the
garagetoassure the burnerandignition deviceswillbe no less
than18 inchesabovethefloor.
•Locateorprotecttheboilersoitcannotbedamagedbya moving
vehicle.
Minimum clearance to combustible materials
1. Hotwater pipesmustbe at least½"from combustible material.
2. Single-wallventpipemustbeatleast6inchesfromcombustible
material.
3. TypeBdouble-wallmetalventpipe—Seeventmanufacturer’s
recommendationfor clearances tocombustible material.
Small space installations
1. When the boiler is located in a closet or small space, provide
clearancesnolessthanthoseshowninFigure1.Theclearances
are required to any surface, whether combustible or non-
combustible.
Table 1 Minimum foundation size
1 Prepare boiler location continued
Clearances from combustible materials: Minimum
Front (provide means of access) 3"
Back 7"
Left side (provide means of access) 6"
Right side 2"
Top GWA052 to GWA105
GWA140
GWA175
GWA210
GWA245
H
35"
35½"
38½"
39¾"
42½"
Boiler
model Minimum foundation
length
Minimum
foundation
width
GWA052 25" 12"
GWA070 25" 12"
GWA105 25" 15"
GWA140 25" 18"
GWA175 25" 21"
GWA210 25" 24"
GWA245 25" 27"
GWA Gas-Fired Water Boilers –Boiler Manual
34 Part Number 670 01 1001 00
Figure 21 Dimensional drawing — ALL DIMENSIONS IN INCHES
13 Dimensions
Boiler
model
number
Supply
tapping
(inches NPT)
Return
tapping
(inches NPT)
Gas connection
& manifold size
(Note 3)
(inches NPT)
“A”
Vent
location
(inches)
“D”
Vent
diameter
(inches)
“W”
Jacket
width
(inches)
“H”
Damper
height
(inches)
GWA052
1
1
/ 4 1
1
/ 41 / 2 5 4 10 45
3
/ 8
GWA070
1
1
/ 4 1
1
/ 41 / 2 5 4 10 52
3
/ 8
GWA105
1
1
/ 4 1
1
/ 41 / 2 6
1
/ 2 513 54
3
/ 8
GWA140
1
1
/ 4 1
1
/ 41 / 2 8 6 16 57
7
/ 8
GWA175
1
1
/ 4 1
1
/ 41 / 2 9
1
/ 2 619 60
7
/ 8
GWA210
1
1
/ 4 1
1
/ 43 / 4 11 722 62
1
/ 8
GWA245
1
1
/ 4 1
1
/ 43 / 4 12
1
/ 2 725 64
7
/ 8
Note 3: Size gas piping from meter to boiler per local utility requirements.

GWA Gas-Fired Water Boilers –Boiler Manual
4Part Number 670 01 1001 00
1 Prepare boiler location continued
Failure tofollowall instructions can result in flue gas
spillage and carbon monoxide emissions, causing
severepersonal injuryor death.
When removing boiler from existing common vent
system:
Atthetime ofremovalof anexistingboiler,thefollowingsteps shall
befollowedwitheachapplianceremainingconnectedtothecommon
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. Visuallyinspecttheventingsystemforpropersizeandhorizontal
pitchanddeterminethereisnoblockage or restriction, leakage,
corrosion or other deficiencies 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
clothesdryersandanyappliancenotconnected to the common
ventingsystem.Turnonanyexhaustfans,such asrangehoods
andbathroomexhausts, sotheywilloperateatmaximumspeed.
Donotoperateasummerexhaust fan. Closefireplacedampers.
d. Place in operation the appliance being inspected. Follow the
lighting/operatinginstructions. Adjustthermostat so appliance
willoperatecontinuously.
e. Test for spillage at draft hood relief opening after 5 minutes of
mainburner operation.Use the flameof amatch orcandle.
f. After it has been determined that each appliance remaining
connectedtothe common ventingsystemproperly vents when
testedasoutlined above, returndoors,windows, exhaust fans,
fireplacedampers,andanyothergas-burningappliancetotheir
previousconditions ofuse.
Any improper operation of common venting system should be
corrected so the installation conforms with the National Fuel Gas
Code,ANSIZ223.1–latest edition. Correctbyresizing toapproach
the minimum size as determined using the appropriate tables in
Part11of thatcode.CanadianinstallationsmustcomplywithB149.1
orB149.2 Installation Code.
Chimney or vent requirements
1. Venting must be installed according to Part 7, “Venting of
Donotalterboilerdraft hood orplaceanyobstruction
or non-certified vent damper in breeching or vent
system.CSAcertificationwill become void.Fluegas
spillage and carbon monoxide emissions will occur
causingsevere personalinjury or death.
Inspect existing chimney before installing boiler.
Failure to clean or replaceperforatedpipeortilelining
willcause severe personal injury ordeath.
Vent system
Equipment”, of National Fuel Gas Code, ANSI Z223.1–latest
edition and applicable building codes. Canadian installations
mustcomply withB149.1 orB149.2 InstallationCodes.
2. See “Ratings”on page35 forminimum chimneyor ventsizes.
Chimneyor vent termination:
•Achimney, or anyvent other thanaType B ventwithlisted
ventcap,mustextendat least 3feetabovethehighestpoint
where it passes through a roof of a building, and at least
2 feethigherthananyportionofabuildingwithinahorizontal
distanceof 10 feet.
•Type B ventswith listedcaps may terminate as in Figure 2
if no closer than 8 feet from a vertical wall or similar
obstruction.
•Otherwise,TypeBventsmustterminateatleast2feetabove
theroofpenetrationandatleast2feethigherthananyportion
ofa building within10 feet.
3. A lined chimney ispreferred andmust be used when required
bylocal, state, provincialandnational codes,laws,regulations
and ordinances. Vitreous tile linings with joints that prevent
retentionofmoistureandlinings made ofnoncorrosivematerials
are best. Advice for flue connections and chimney linings can
beobtainedfrom local gasutility.TypeBdouble-wallmetalvent
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
existsfor condensation to occur.Condensationcan damagea
masonry chimney. Williamson-Thermoflo recommends the
followingto prevent possibledamage.
a. Line chimney with corrosion-resistant metal liner such as
AL29-4C®single-wall stainless steel or B-vent. Size liner
perNational FuelGas Code ANSIZ223.1–latest edition.
b. Providedrain trapto removeany condensate.
5. Where two or more gas appliances vent into a common
chimney or vent, equivalent area should be at least equal to
areaof vent outleton largestappliance plus 50percent ofvent
outletareaofadditional appliance.
Figure 2 Terminations with Type B vent fitted with
listed cap, provided vent is at least 8 feet
from any vertical wall or similar obstruction
Thefollowing requirements applywhen youremove
an existing boiler from a vent system shared with
otherappliances. If the new boiler will not use the
common vent, you must test (as described below)
eachremainingappliance —operatingbyitself —to
verify that the vent system operates adequately.
GWA Gas-Fired Water Boilers –Boiler Manual
33Part Number 670 01 1001 00
Figure 20 Gas control assembly
12 Replacement parts continued
Item
number Description Manufacturer Manufacturer’s part number International Comfort
Products
part number
Standing pilot —Natural gas components
1Gas valve,
1
/ 2 "x
1
/ 2 ", GWA052 through GWA175
Gas valve,
3
/ 4 "x
3
/ 4 ", GWA210 and GWA245
Honeywell
Robertshaw
Honeywell
VR8200A2116
7200ER
VR8300C4050
511044360WT
511044256WT
2Pilot assembly kit with orifice International Comfort Products 510811005WT
3Tubing, pilot, aluminum 560742860WT
4Tubing, thermocouple 511724254WT
5Transformer relay 510312167WT
not
shown Wiring harness 591391862WT

GWA Gas-Fired Water Boilers –Boiler Manual
5Part Number 670 01 1001 00
Table 2 Corrosive contaminants and likely locations
Topreventpotentialofseverepersonalinjuryordeath,
check for products or areas listed below before
installingboiler.Ifanyofthesecontaminantsarefound:
•Removecontaminants permanently.
—OR —
•Isolateboilerandprovideoutsidecombustionair.See
national, provincial or local codes for further
information.
Pleasereviewthefollowing information onpotentialcombustion air
contaminationproblems.
SeeTable2 forproducts andareaswhichmaycause contaminated
combustionair.
Air contamination Air openings
Combustionairand ventilation openingsmustcomply withSection
5.3,“AirforCombustionandVentilation”,ofNationalFuelGasCode
ANSI Z223.1–latest edition, or applicable local building codes.
Canadian installations must comply with B149.1 or B149.2
InstallationCodes.
See table below for minimum combustion/ventilation air opening
sizes.Where openings are required, provide two (2) openings —
onewithin 12 inchesofthe ceiling,theother within12inches ofthe
floor,as showninthe table illustrations.
Provide adequate combustion and ventilation air to
assure proper combustion and reduce the risk of
severepersonal injury,death or substantialproperty
damage caused by flue gas spillage and carbon
monoxideemissions.
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
1 Prepare boiler location continued
GWA Gas-Fired Water Boilers –Boiler Manual
32 Part Number 670 01 1001 00
Figure 19 Trim assembly
12 Replacement parts continued
Item
number Description Manufacturer Manufacturer’s part number International
Comfort
Products
part number
1Pressure relief valve, ASME, 30 PSIG, ¾"maleinlet
Pressure relief valve, ASME, 30 PSIG, ¾" female inlet
(Fittings shown are factory-installed on boiler.)
Conbraco
Watts 10-407-10 M330 511546920WT
Conbraco
Watts 10-408-05 335 511546924WT
2Combination pressure-temperature gauge, with 2½"short
shank Ametek ENFM PTA-1088 4104 510218099WT
3Drain valve, ¾"
(Fittings shown are included with boiler.) Conbraco Hammond Valve
Matco-Norca
Watts
31-606-01
710
205F04
BD-2C 511210423WT
4Circulator (Fittings shown are shipped loose with boiler.) Taco 007 511405113WT
5Circulator gasket, universal (2 per boiler) International Comfort Products 590317535WT
not
shown Circulator hardware kit, includes: 2 flanges, 4 nuts, 4 screws, 2 pipe nipples —
1" NPT —GWA052 through GWA140
1¼"NPT—GWA175 through GW245
International Comfort Products
381354525WT
381354526WT
6Circulator wiring harness International Comfort Products 591319793WT

GWA Gas-Fired Water Boilers –Boiler Manual
6Part Number 670 01 1001 00
Air openings continued
2 Prepare boiler
Table 3 Manifold orifice sizing
Place boiler/crate near position
1. Leave boiler in crate and on pallet until installation site is
ready.
2. Move entire crate and palletnext toselected location.
3. Remove crate. Leave boiler on pallet.
4. Remove boiler from pallet asfollows:
a. Tilt left side of boiler up and place a board under left legs.
b. Tiltboiler the otherway and placea board underright legs.
c. Slide boiler backwards offpallet andinto position.
Do not drop boiler or bump jacket on floor or pallet.
Damageto boilercan result.
5. Check level.
a. Shim legs, if necessary.
b. Donot alterlegs.
Placement and setup 3. Level and straightenburners.
Burners must be properly seated in slots in burner
restwith their openingsfaceup.Mainburnerorifices
mustinjectdowncenterofburner.Failure toproperly
seat burners will result in severe personal injury,
deathor substantial propertydamage.
4. Reinstall access panel.
Donot operateboiler without access panel secured
in place.Failure to comply could cause momentary
flame rollout on ignition of main flame, resulting in
possiblefire orpersonal injuryhazard.
Inspect orifices and burners
1. Remove front jacket door. Remove base access panel (See
Figure17, item 4, page 30).
2. Checkforcorrectly-sizedmanifoldorifices.SeeTable3forsizing.
(The orifice size is stamped on the orifice spud barrel.)
Correctly-sizedmanifoldorificesmustbeused.Failure
todo so willresult inseverepersonal injury, deathor
substantialproperty damage.
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
requiredforthefiringrateof all appliances, butalsotohandletheair
movementrate of theexhaust fans orair movers usingair from the
buildingor space.
Motorized air dampers
If the air openings are fitted with motorized dampers, electrically
interlockthe damperto:
•Preventthe boilerfrom firingif thedamper isnot fullyopen.
•Shut the boiler down should the damper close during boiler
operation.
To accomplish this interlock, wire an isolated contact (proving the
damperopen) inserieswith the thermostat input to the boiler.The
boilerwill not startif this contactis open,andwill shutdownshould
itopenduring operation.
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 #49 1.30 mm #56
Note 1: For U. S. elevations above 2,000 feet, contact your International Com-
fort Products supplier for details.
GWA Gas-Fired Water Boilers –Boiler Manual
31Part Number 670 01 1001 00
Figure 18 Jacket assembly
12 Replacement parts continued
Theboiler contains ceramicfiber and fiberglassmaterials. Use carewhen handling thesematerials per
instructions onpage 23of this manual.Failure to comply could resultin severepersonalinjury.
Item
number Description International Comfort
Products
part number
1Junction box, 4 x 4
(Available at local supply house)
1a Junction box, 2 x 4
(Available at local supply house)
2Jacket panel, left side, with
insulation 431223425WT
3Jacket panel, right side, with
insulation 431223426WT
4Jacket
panel,
door
GWA052 & GWA070
GWA105
GWA140
GWA175
GWA210
GWA245
431223450WT
431223451WT
431223452WT
431223453WT
431223454WT
431223455WT
Item
number Description International Comfort
Products
part number
5Jacket
panel, top GWA052 & GWA070 GWA105
GWA140
GWA175
GWA210
GWA245
431223433WT
431223434WT
431223435WT
431223436WT
431223437WT
431223438WT
6Jacket
cross tie GWA052 & GWA070 GWA105
GWA140
GWA175
GWA210
GWA245
431223507WT
431223508WT
431223509WT
431223510WT
431223511WT
431223512WT
7Jacket
panel,
interior,
with
insulation
GWA052 & GWA070
GWA105
GWA140
GWA175
GWA210
GWA245
431223427WT
431223428WT
431223429WT
431223430WT
431223431WT
431223432WT
8Jacket
panel,
rear, with
insulation
GWA052 & GWA070
GWA105
GWA140
GWA175
GWA210
GWA245
431223444WT
431223445WT
431223446WT
431223447WT
431223448WT
431223449WT

GWA Gas-Fired Water Boilers –Boiler Manual
7Part Number 670 01 1001 00
Perform hydrostatic pressure test
Pressuretestboilerbeforeattaching water orgaspiping orelectrical
supply (except as noted below).
Prepare boiler for test
1. Remove the shipping nipple (from GWA supply tapping) and
remove the boiler relief valve.Temporarily plug the relief valve
tappingwith a¾" NPTpipe plug.
2. Remove 1¼" nipple, reducing tee and drain valve from
accessorybag. Installin boilerreturn connectionas shownon
in Figure 19, item 3, page 32. Install circulator on either the
return or supply.
3. Remove1¼"nipple,1¼"tee,bushingandpressure/temperature
gaugefromaccessory bag. Pipetoboiler supply connectionas
showninFigure19,item 2, page32.(Usepipedopesparingly.)
4. Connect a hose to boiler drain valve, theother endconnected
to a fresh water supply. Make sure hose can also be used to
drainboiler aftertest.
5. Connecta nipple and shutoff valvetosystemsupplyconnection
onthe1¼"tee.This valvewillbeused to bleedair duringthefill.
(Valveand nippleare not includedwith boiler.)
6. Connecta nippleandshutoffvalveto system returnconnection
(at circulator flange if circulator installed on return).This valve
willbe used tobleedairduringthefill.(Valveand nipplearenot
includedwithboiler.)
7. Temporarily plug the air elimination tapping (next to supply
tapping).
2 Prepare boiler continued
Pressure test
Fill and pressure test
1. Open the shutoff valves you installed on supply and return
connections.
2. Slowly open boiler drain valve and fresh water supply to fill
boilerwith water.
3. Whenwater flowsfrom shutoff valves,close boilerdrainvalve.
4. Close shutoff valves.
5. Slowlyreopen boilerdrain valve untiltest pressureofnot more
than45 psiis reached on the pressure/temperaturegauge.
6. Test at no more than 45 psi for no more than 10 minutes.
Donotleaveboilerunattended. A coldwaterfillcould
expand and cause excessive pressure, resulting in
severepersonal injury,death or substantialproperty
damage.
7. Make sure constant gauge pressure has been maintained
throughouttest. Checkfor leaks.Repair if found.
Leaksmustbe repairedatonce.Failuretodoso can
damage boiler, resulting in substantial property
damage.
Do not use petroleum-based cleaning or sealing
compoundsinboilersystem.Severedamagetoboiler
willoccur,resulting insubstantial propertydamage.
Drain and remove fittings
1. Disconnect fill water hose from water source.
2. Drainboiler atdrainvalveor out hose,whicheverprovides best
access to drain. Remove hose after draining if used to drain
boiler.
3. Remove nipples, valves and plus unless they will remain for
usein the systempiping.
4. Remove plug fromreliefvalvetapping.SeeSection 3,page 10,
toreplace reliefvalve.
GWA Gas-Fired Water Boilers –Boiler Manual
30 Part Number 670 01 1001 00
Figure 17 Base assembly, manifold, orifices and burners
12 Replacement parts continued
Item
number Description International Comfort
Products
part number
Base assembly kit GWA052 & GWA070
GWA105
GWA140
GWA175
GWA210
GWA245
381354200WT
381354201WT
381354202WT
381354203WT
381354204WT
381354205WT
1Base side panel (in Base assembly)
2Base front cross-tie assembly (in Base assembly)
3Base back cross-tie assembly (in Base assembly)
4Base access panel (in Base assembly)
5Base pan angle, left side (in Base assembly)
6Base pan angle, right side (in Base assembly)
7Base pan (in Base assembly)
8Burner rest (in Base assembly)
9Base insulation kit
(includes insulation for
all base parts above
plus gasket material
needed between block
assembly and base)
GWA052 to GWA140
GWA175 to GWA245 381354210WT 381354211WT
10 Boiler leg kit 590424252WT
11 Manifold GWA052
GWA070
GWA105
GWA140
GWA175
GWA210
GWA245
591126615WT
591126616WT
591126617WT
591126618WT
591126619WT
591126556WT
591126557WT
12 Main burner orifice, sea level 560528997WT
13 Burner, stainless steel 512200077WT
14 Burner with pilot
bracket
(not shown)
Standing pilot 512200079WT
Spark-ignited pilot 512200078WT
15 Screw, 10-32 x 3/8STP type D hx, washer head
slot ZP available at local supply
house
16 Rollout thermal fuse element 512050230WT

GWA Gas-Fired Water Boilers –Boiler Manual
8Part Number 670 01 1001 00
1. Connect from draft hood or vent damper outlet to chimney or
vent with same size vent connector.
2. Where possible, vertical venting to the outside from the draft
hoodor ventdamper outlet willoffer bestperformance.
3. Wherehorizontal ventconnectorisused, slope upwardatleast
¼" per lineal foot toward chimney or vent and support with
hangersto preventsagging.
4. Breechingmustnotbeconnectedtoanyportionofamechanical
draftsystem that can operate under positive pressure.
Long horizontal vent connector, excessive number
of elbow or tees, or other obstructions that restrict
the flow of combustion gases should be avoided.
Severepersonalinjury, deathorsubstantial property
damagecouldresult.
Install vent piping
These systems are used on gas-fired boilers with
vent dampers asshipped fromfactory.Boiler willnot
operatewithoutvent damperinstalled.
Only vent dampers listed in the Replacement parts
listonpage29 are certifiedforuse with GWAboilers.
Anyother vent damperinstalled couldcause severe
personalinjury ordeath.
Damper blade
Standing pilot ignition systems—See vent manufacturer’s
instructions to install plug (shipped with damper) in damper hole.
Forstandingpilot boilers only, installplug with3/8"diameterhole in
ventdamperhole.
Spark-ignited pilot systems—See vent manufacturer’s
instructions to install plug (shipped with damper) in damper hole.
For spark-ignited pilot boilers only, install plug with no hole in vent
damperhole.
Minimum clearances
Provide a minimum of 6" between the vent damper and any
combustible material. (See “Minimum clearance to combustible
materials,”page3, forminimum clearance fromjacket toptoceiling
tomaintainthis dimension.)
Vent damper
Draft hood installation
1. Orient draft hood with spill switch mounting holes to front of
boiler as shown in Figure 3.
2. Secure draft hood to outlet at top of boiler with sheet metal
screws.
Figure 3 Spill switch with wire harness
Draft hood & spill switch
3. Bottom of draft hood or skirt must have clearance dimension
above jacket top panel as indicated on draft hood.
Do not alter boiler draft hood or place any
obstruction or non-approved vent damper in
breeching or vent system. CSA certification will
become void. Flue gas spillage and carbon
monoxide emissions will occur causing severe
personal injury or death.
Improper orientation of spill switch may cause
boiler to shut down. The loss of heat can result in
significant damage due to freezing.
Spill switch installation
1. Fasten spill switch to draft hood as shown in Figure 3.
2. See Wiring diagram to connect wires:
a. Standing pilot boiler —see page 19.
b. Spark-ignited pilot boiler —see Control Supplement.
2 Prepare boiler continued
GWA Gas-Fired Water Boilers –Boiler Manual
29Part Number 670 01 1001 00
Figure 16 Section assembly, flue collector, draft hood and vent damper
12 Replacement parts
Item
number Description International Comfort
Products
part number
not shown Replacement
section
assembly
GWA052
GWA070
GWA105
GWA140
GWA175
GWA210
GWA245
321114501WT
321114501WT
321114502WT
321114503WT
321114504WT
321114505WT
321114506WT
1Radiation plate
(1 per joint) 460003700WT
2Collector
hood GWA052 GWA070
GWA105
GWA140
GWA175
GWA210
GWA245
381354625WT
381354626WT
381354627WT
381354628WT
381354629WT
381354630WT
381354631WT
3Draft hood GWA052
GWA070
GWA105
GWA140
GWA175
GWA210
GWA245
450021270WT
450021271WT
450021272WT
450021273WT
450021274WT
450021275WT
450021276WT
Item
number Description International Comfort
Products
part number
4High limit, 30°differential,
with well Honeywell L4080D1036 White-Rodgers 11B81-3 510312250WT
5Spill switch 510350105WT
6Vent
damper 4" GWA052 GWA070 Effikal RVGP-KS-4BKF *Johnson Controls Q35GB-2 510512350WT
5" GWA105 Effikal RVGP-KS-5BKF
*Johnson Controls Q35GD-2 510512351WT
6" GWA140
GWA175 Effikal RVGP-KS-6BKF *Johnson Controls Q35GF-2 510512352WT
7" GWA210
GWA245 Effikal RVGP-KS-7BKF *Johnson Controls Q35GH-2 510512353WT
*Johnson Controls damper assemblies consist of M35BC
actuator and Y15 vent pipe
7Vent damper actuator Effikal RVGP
Johnson M35BE-1C only with vent damper above
8Vent damper harness 591391795WT

GWA Gas-Fired Water Boilers –Boiler Manual
9Part Number 670 01 1001 00
Figure 4 Vent damper assemblies
Damper installation
Do not modify draft hood or vent damper, or make
another connection between draft hood and vent
damperorboilerexceptasnotedbelow.Thiswill void
CSA certification and will not be covered by
Williamson-Thermoflo warranty. Any changes will
cause severe personal injury, death or substantial
propertydamage.
1. Install vent damper horizontally or vertically as shown in vent
damper manufacturer’s instructions. Vent damper must be
installedso thatit servesonly oneboiler andso damperblade
indicator is visible to the user.See Figure 4.
2. Screws or rivets used to secure the vent damper to the draft
hoodmust not interferewith rotationof the damperblade.
3. Install damper harness between damper actuator and hole in
jacketleft side panel.See Figure3, page8.
Use strain relief connectors and locknuts to secure both ends
ofdamper harness.
Keep wiring harness clear of all hot surfaces.Wire
insulationcouldbedamaged, causingriskofelectrical
short-circuit.
4. Read and applythe harnessplugwarning label(shown upper-
left)so thatit is visible after installation
5. Plug damper harnessreceptacle intodamper harnessplug.
Bypassing (jumpering) vent damper will cause flue
products such as carbon monoxide to escape into
the house.This will cause severe personal injury or
death.
Afterboilerhas operatedonce,ifeitherendofharness
is disconnected, the system safety shutdown will
occur. The boiler will not operate until harness is
reconnected.
Effikaldamper —Damper holdopen switch mustbe
inAutomaticOperationpositionforsystemtooperate
properly.
Vent damper continued
2 Prepare boiler continued
GWA Gas-Fired Water Boilers –Boiler Manual
28 Part Number 670 01 1001 00
Is 24VAC present across transformer terminals C& Y?
Is damper harness securely plugged in at both ends?
Secure connections.
Check for open thermostat, LWCO, high limit, spill switch or
rollout thermal fuse element contacts or check for loose
wire connections.
If LWCO, spill switch or rollout thermal fuse
element contacts are open, determine cause
and correct condition. Failure to do so will
cause severe personal injury, death or
substantial property damage.
Check/repair out of round stack section.
Does vent damper rotate open?
Is 24VAC present across transformer terminal Cand yellow
wire on vent damper connector?
Is 24VAC present across gas valve terminals?
Open thermostat contacts for 30 seconds. Vent damper will
rotate to closed position. Close thermostat contacts. Vent
damper will rotate to open position.
Is 24VAC present across gas valve terminals?
Remove damper harness from
damper harness plug.
TEMPORARILY install jumper
between terminal 2and
terminal 5on damper plug in
boiler wiring harness. See
Table, right.
Does boiler fire?
No Yes
No Yes
Chart 1 — Standing pilot — Boiler will not fire
Check for loose wire connections or bad relay on
transformer.
No Yes
Is vent damper rotated open?
No Yes
No Yes
•Replace actuator.
•Retest.
Check continuity of each wire in damper harness. Does
continuity exist for each wire?
See Table right.
•Replace damper
wiring harness.
•Retest.
•Replace gas valve.
•Retest.
Is main flame on now?
No Yes
Retest.
No Yes
No Yes
No Yes
No Yes
•Replace damper actuator.
•Retest.
•Turn gas valve cock to
ON position.
•Retest.
•Replace gas valve.
•Retest.
Is gas valve cock turned to ON position?
No Yes
Before proceeding, follow "Troubleshooting sequence" on page 27. If problem persists, then:
11 Troubleshooting continued

GWA Gas-Fired Water Boilers –Boiler Manual
10 Part Number 670 01 1001 00
Table 4 Water pipe size (based on 20 °F rise)
General
If installation is to comply with ASME or Canadian requirements,
anadditionalhightemperaturelimitisneeded.Installcontrolinsupply
piping between boiler and isolation valve. Set second control to
minimum20 °F abovesetpoint offirst control. Maximumallowable
setpointis 240 °F.See page19 forwiring.
Alow water cutoffdevice isrequired when boileris installedabove
radiation level or by certain state or local codes or insurance
companies. Use low water cutoff designed for water installations.
Electrodeprobe-typeis recommended.Purchaseand installintee
supplypiping above boiler.
Use backflow check valve in cold water supply if required by local
codes.
SeeTable4andFigure5(diaphragm-typeorbladder-typeexpansion
tank)orFigure6 (closed-type expansiontank)on page 11fornear-
boilerpiping forsystemsdesigned forreturn waterat least130 °F.
See page 12 (Figures 8 and 9) for near-boiler piping for low-
temperatureor high-volumesystems.
Seepage 11 (Figure7) forboilersused withrefrigeration systems.
Near-boiler piping
3 Install water piping
Relief valve
Installrelief valve verticallyin¾" tapping on side of boiler.See the
tagattached tothe relief valve formanufacturer’s instructions.
To avoid water damage or scalding due to valve
operation,dischargeline must beconnected to relief
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
throughoutitsentire length.
•Discharge line must pitch downward from the valve
andterminate at least6" above thefloor drain where
any discharge will be clearly visible.
•Thedischargelineshallterminateplain,not threaded,
withamaterialserviceablefortemperaturesof375°F
orgreater.
•Donotpipethedischargeto any placewherefreezing
couldoccur.
•Noshutoff valve shallbe installedbetween therelief
valveandboiler,or inthe dischargeline.Do notplug
orplace anyobstruction in the discharge line.
•Failure to comply with the above guidelines could
resultinfailure of thereliefvalveto operate,resulting
in possibility of severe personal injury, death or
substantialproperty damage.
•Test the operation of the valve after filling and
pressurizing system by lifting the lever. Make sure
thevalve discharges freely.Ifthevalvefailstooperate
correctly, replace it with a new relief valve.
Water piping —multiple zone systems
Install system piping using either circulator zoning or zone valve
zoning.Install expansiontank onsuction side of system circulator.
Always connect fill line only at the expansion tank —never at
anotherpoint inthe system.
Circulator
The circulator is shipped loose (wiring pre-attached to boiler) to
allowyoutolocateiteither in thereturnorsupplypiping,as desired.
See page 11 for 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.Alwaysinstallthesystemfillconnection at thesamepoint
as the expansion tank connection to the system. Figures 5 and 6
showtypical near-boiler piping connections.
Expansion tank
Diaphragm-type or bladder-type expansion tank —
Figure 5
1. Ensureexpansion tank sizewillhandleboilerandsystem water
volume and temperature.Tank mustbelocated inboiler return
pipingasclose toboileraspossible,beforeinletsideofcirculator.
Seetank manufacturer’s instructions fordetails.
2. Install an automatic airvent asshown.
Closed-type expansion tank —Figure 6
1. Ensureexpansion tank sizewillhandleboilerandsystem water
volumeand temperature.See tankmanufacturer’s instructions
fordetails.
2. Connect tank to ½" NPT tapping located behind supply outlet,
using ½" NPT piping. Pitch any horizontal piping up towards
tank1 inch per5 feet of piping.
Undersizedexpansion tankscause system water to
be lost from relief valve and makeup water to be
addedthrough fill valve.Eventual section failurecan
result.
Near-boiler piping continued
Boiler model
number To system From system
GWA052 ¾"¾"
GWA070 1" 1"
GWA105 1" 1"
GWA140 1" 1"
GWA175 1¼" 1¼"
GWA210 1¼" 1¼"
GWA245 1½" 1½"
GWA Gas-Fired Water Boilers –Boiler Manual
27Part Number 670 01 1001 00
11 Troubleshooting
Verify proper operation after servicing. •See vent
dampermanufacturer’sinstructionspackedwith vent
damperforadditional information.Failure tocomply
could result in severe personal injury, death or
substantialpropertydamage.
Figure 15 Manually opening vent damper
Labelall wires priorto disconnectionwhenservicing
controls. Wiring errors can cause improper and
dangerousoperation.
Neverjumper (bypass)rollout thermalfuse element
orany other deviceexcept formomentary testing as
outlinedin“Chart1”,page28.Severe personal injury,
deathor substantialproperty damage can result.
Burneraccesspanelmustbein position during boiler
operation to prevent momentary flame rollout on
ignition of main flame. Severe personal injury or
substantialpropertydamage will result.
Before troubleshooting:
1. Have the followingitems:
a. Voltmeter that can check 120VAC and 24VAC.
b. Microammeterwith ascale range of 0-10.
c. Continuity checker.
d. U-tubemanometer.
2. Checkfor120VAC(minimum102VACto maximum 132VAC)
toboiler.
3. Makesure thermostatiscallingforheat and contacts(including
appropriate zone controls) are closed. Check for 24 VAC
betweenthermostat wire nuts and ground.
Troubleshooting sequence:
1. Before proceeding, check for:
•Loose connections, blown fuse or service switch off?
•Highlimit switchset below boiler water temperature?
•Thermostatset below roomtemperature?
•Gasnot turnedon atmeter or boiler?
•Incominggas pressure lessthan:
5" w.c.for natural gas? 11" w.c. for propane gas?
2. If all of the above check correctly, check gas pressures:
a. Withboiler off
•13" w.c. maximum natural or propane gas pressure
upstream of gas valve.
b. Withboiler on:
•5" w.c. minimum natural gas pressure or 11" w.c.
propane gas pressure upstream of gas valve.
•3.5" w.c. minimum natural gas pressure or 10" w.c.
propane gas pressure downstream tapping on gas
valve —Can be adjusted by regulator on gas valve.
c. If gas pressure is incorrector gasis notavailableto boiler,
contactgas supplierto correct beforeproceedingfurther.
3. Checkpilot operation-Follow “Lighting Instructions”,pages 20
and21.
•If gas is available and you cannot obtain a pilot flame, try
purgingthegas lineandcleaning pilotandpilot gastubing.
Follow“LightingInstructions”again. If youstillcannotobtain
aflame,replace pilot burnerandgastubing. Ifthisdoesnot
allowyou toobtain apilot flame, replace gas valve.
•Ifyouobtainapilot flame,butpilotwillnotremainon,replace
thermocouple.Ifthisdoes notcorrectproblem,replace gas
valveandpilot burner.
•Ifpilot stays on,but main gaswill not come on, proceed to
page 28.
In event of vent damper failure:
Effikal vent damper
Iftroubleshootingchartrecommendsreplacingactuatorandactuator
isnotimmediately available,damperblade can befixed in anopen
positiontoallowboileroperation. Manually turningbladecancause
actuatordamage. Follow theseinstructions onlyincase ofno heat
ordamper actuator malfunction.
1. Move damper service switch to Hold Damper Open position.
Applycallforheattoboiler.Damperbladeshould thenrotate to
Openposition and boiler will fire.
2. If step 1does notopen damper,manually rotatedamper blade
to open position using wrench or pliers on flat shaft between
damperand actuator.Boilerwill fire.Verify thatdamper service
switchis inHold DamperOpen position.(Figure 15)
3. Donot leave ventdamperpermanentlyinthisposition.Replace
actuator immediately. If vent damper is left in Open position,
boilerwill not operateat publishedefficiencies.
Johnson Controls vent damper
Iftroubleshootingchartrecommendsreplacingactuatorandactuator
isnotimmediately available,damperblade can befixed in anopen
positionto allowboiler operation.Follow theseinstructions onlyin
caseof no heator damperactuator malfunction.See Figure 15.
1. Turn offpowertoboiler.
Failure toturnoffpowerto boiler canresult in severe
personalinjury,deathorsubstantialpropertydamage.
2. See ventdamper manufacturer’s instructions for procedure to
fixvent damperin openposition.
3. Turn onpowertoboiler.
4. Using wrench or pliers on flat shaft section, manually rotate
damperbladeuntilgreenlightturnson.Boilerwillfire.(Figure 15)
5. Donot leave ventdamperpermanentlyinthisposition.Replace
actuator immediately. If vent damper is left in Open position,
boilerwill not operateat publishedefficiencies.