Gas Fired Hot Water Boiler 67001100100

User Manual: Gas-Fired Hot Water Boiler

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Page Count: 36

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

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 certificate” found on

page 18.

Contents Page

1 Prepare boiler location ........................................................2

2 Prepare boiler ..................................................................... 6

3 Install water piping ............................................................ 10

4 Install gas piping ............................................................... 13

5 Field wiring ....................................................................... 14

6 Start-up ............................................................................ 15

7 Checkout procedure ......................................................... 18

8 Sequence of operation — standing pilot boilers ................. 19

9 Lighting instructions — GWA standing pilot boilers ........... 20

10 Service and maintenance ................................................. 22

11 Troubleshooting ................................................................ 27

12 Replacement parts ........................................................... 29

13 Dimensions ...................................................................... 34

14 Ratings ............................................................................. 35

Boiler Manual

Gas-Fired Water Boilers

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

installing. 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 transportation

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 qualified 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

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

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 GWA boiler gas manifold and controls met 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:

•System water piping

•Venting connections

•Gas supply piping

•Electrical power

❏Check area around boiler. Remove any combustible materials,

gasoline and other flammable liquids.

Failure to keep boiler area clear and free of

combustible 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 in boiler water causing system and boiler

to freeze and leak.

Codes & checklist

Failure to adhere to the guidelines below can

result in severe personal injury, death or

substantial 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

performing maintenance.

Boiler operation —

3. Do not block flow 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 qualified 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

compounds in boiler system. Water seal deterioration will

occur, causing leakage between boiler sections, circulator

flanges, 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. Mineral

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 flammable when exposed to high temperatures. If

glycol is allowed to accumulate in or around the boiler or any

other potential ignition source, a fire can develop. In order to

prevent potential severe personal injury, death or substantial

property damage from fire 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 possible

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!

GWA

Gas-Fired Water Boilers – Boiler Manual

35Part Number 670 01 1001 00

Install GWA boilers for residential radiant panel systems, converted gravity

heating systems or other low water temperature applications per instructions

in this manual to avoid damage due 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

requirements of the building and nothing need be added for normal piping and pickup.

Ratings are based on a piping and pickup allowance of 1.15. An additional allowance

should be made for unusual piping and pickup loads.

3. See information at right for model number suffixes. Letters shown 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

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.

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

The GWA boiler is approved for installation on combustible flooring,

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

foundation pad if any of the following is true:

•floor can become flooded.

•the boiler mounting area is not level.

2. See Table 1 for minimum foundation dimensions.

Residential garage installation

Take the following special precautions when installing the boiler in

a residential garage. If the boiler is located 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.

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 6 inches from combustible

material.

3. Type B double-wall metal vent pipe — See vent manufacturer’s

recommendation for clearances to combustible material.

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 clearances

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

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

5 4 10 45

GWA070

5 4 10 52

GWA105

513 54

GWA140

8 6 16 57

GWA175

619 60

GWA210

11 722 62

GWA245

725 64

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 to follow all instructions can result in flue 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 horizontal

pitch and determine there is no blockage 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

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 flame 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 or vent requirements

1. Venting must be installed according to Part 7, “Venting of

Do not alter boiler draft hood or place any obstruction

or non-certified 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.

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

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. See “Ratings” on page 35 for minimum chimney or vent sizes.

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

obstruction.

•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 materials

are best. Advice for flue 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. Williamson-Thermoflo 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

chimney 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.

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

The following requirements apply when you remove

an existing boiler from a vent system shared with

other appliances. If the new boiler will not use the

common vent, you must test (as described below)

each remaining appliance — operating by itself — 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,

", GWA052 through GWA175

Gas valve,

", 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

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 2 for products and areas which may cause contaminated

combustion air.

Air contamination Air openings

Combustion air and ventilation openings must comply with Section

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.

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 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 floor or pallet.

Damage to boiler can result.

5. Check level.

a. Shim legs, if necessary.

b. Do not alter legs.

Placement and setup 3. Level and straighten burners.

Burners must be properly seated in slots in burner

rest with their openings face up. Main burner orifices

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

flame rollout on ignition of main flame, resulting in

possible fire or personal injury hazard.

Inspect orifices and burners

1. Remove front jacket door. Remove base access panel (See

Figure 17, item 4, page 30).

2. Check for correctly-sized manifold orifices. See Table 3 for sizing.

(The orifice size is stamped on the orifice spud barrel.)

Correctly-sized manifold orifices must be used. Failure

to do so will result in severe personal injury, death or

substantial property 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

required for the firing 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.

Motorized air dampers

If the air openings are fitted with motorized dampers, electrically

interlock the damper to:

•Prevent the boiler from firing 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.

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

The boiler contains ceramic fiber and fiberglass materials. Use care when handling these materials per

instructions on page 23 of this manual. Failure to comply could result in severe personal injury.

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

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 GWA 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

accessory bag. Install in boiler return connection as shown on

in Figure 19, item 3, page 32. Install circulator on either the

return or supply.

3. Remove 1¼" nipple, 1¼" tee, bushing and pressure/temperature

gauge from accessory bag. Pipe to boiler supply connection as

shown in Figure 19, item 2, page 32. (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 connection

on the 1¼" tee. This valve will be used to bleed air during the fill.

(Valve and nipple are not included with boiler.)

6. Connect a nipple and shutoff valve to system return connection

(at circulator flange if circulator installed on return). This valve

will be used to bleed air during the fill. (Valve and nipple are not

included with boiler.)

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

boiler with water.

3. When water flows 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 fill 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 fill 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, valves and plus unless they will remain for

use in the system piping.

4. Remove plug from relief valve tapping. See Section 3, page 10,

to replace relief valve.

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

hood or vent damper outlet will offer best performance.

3. Where horizontal vent connector is used, slope upward at least

¼" per lineal foot toward chimney or vent and support with

hangers to prevent sagging.

4. Breeching must not be connected to any portion of a mechanical

draft system 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.

Severe personal injury, death or substantial property

damage could result.

Install vent piping

These systems are used on gas-fired boilers with

vent dampers as shipped from factory. Boiler will not

operate without vent damper installed.

Only vent dampers listed in the Replacement parts

list on page 29 are certified for use with GWA boilers.

Any other vent damper installed could cause severe

personal injury or death.

Damper blade

Standing pilot ignition systems— See vent manufacturer’s

instructions to install plug (shipped with damper) in damper hole.

For standing pilot boilers only, install plug with 3

/8" diameter hole in

vent damper hole.

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

damper hole.

Minimum clearances

Provide a minimum of 6" between the vent damper and any

combustible material. (See “Minimum clearance to combustible

materials,” page 3, for minimum clearance from jacket top to ceiling

to maintain this 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

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

damper or boiler except as noted below. This will void

CSA certification and will not be covered by

Williamson-Thermoflo warranty. Any changes will

cause severe personal injury, death or substantial

property damage.

1. Install vent damper horizontally or vertically as shown in vent

damper manufacturer’s instructions. Vent damper must be

installed so that it serves only one boiler and so damper blade

indicator is visible to the user. See Figure 4.

2. Screws or rivets used to secure the vent damper to the draft

hood must not interfere with rotation of the damper blade.

3. Install damper harness between damper actuator and hole in

jacket left side panel. See Figure 3, page 8.

Use strain relief connectors and locknuts to secure both ends

of damper harness.

Keep wiring harness clear of all hot surfaces. Wire

insulation could be damaged, causing risk of electrical

short-circuit.

4. Read and apply the harness plug warning label (shown upper-

left) so that it is visible after installation

5. Plug damper harness receptacle into damper harness plug.

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.

After boiler has operated once, if either end of harness

is disconnected, the system safety shutdown will

occur. The boiler will not operate until harness is

reconnected.

Effikal damper — Damper hold open switch must be

in Automatic Operation position for system to operate

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 C and 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 2 and

terminal 5 on damper plug in

boiler wiring harness. See

Table, right.

Does boiler fire?

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

•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

•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,

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 first control. Maximum allowable

setpoint is 240 °F. See page 19 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

supply piping above boiler.

Use backflow check valve in cold water supply if required by local

codes.

See Table 4 and Figure 5 (diaphragm-type or bladder-type expansion

tank) or Figure 6 (closed-type expansion tank) on page 11 for near-

boiler piping for systems designed for return water at least 130 °F.

See page 12 (Figures 8 and 9) for near-boiler piping for low-

temperature or high-volume systems.

See page 11 (Figure 7) for boilers used with refrigeration systems.

Near-boiler piping

3 Install water 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 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

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 threaded,

with a material serviceable for temperatures of 375 °F

or greater.

•Do not pipe the discharge to any place where freezing

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, resulting

in possibility of severe personal injury, death or

substantial property damage.

•Test the operation of the valve after filling and

pressurizing 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.

Water piping — multiple zone systems

Install system piping using either circulator zoning or zone valve

zoning. Install expansion tank on suction side of system circulator.

Always connect fill line only at the expansion tank — never at

another point in the system.

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 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. Always install the system fill connection at the same point

as the expansion tank connection to the system. Figures 5 and 6

show typical near-boiler piping connections.

Expansion tank

Diaphragm-type or bladder-type expansion tank —

Figure 5

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 6

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 fill valve. Eventual section failure can

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

damper manufacturer’s instructions packed with vent

damper for additional information. Failure to comply

could result in severe personal injury, death or

substantial property damage.

Figure 15 Manually opening vent damper

Label all wires prior to disconnection when servicing

controls. Wiring errors can cause improper and

dangerous operation.

Never jumper (bypass) rollout thermal fuse element

or any other device except for momentary testing as

outlined in “Chart 1”, page 28. Severe personal injury,

death or substantial property damage can result.

Burner access panel must be in position during boiler

operation to prevent momentary flame rollout on

ignition of main flame. Severe personal injury or

substantial property damage will result.

Before troubleshooting:

1. Have the following items:

a. Voltmeter that can check 120 VAC and 24 VAC.

b. Microammeter with a scale range of 0-10.

c. Continuity checker.

d. U-tube manometer.

2. Check for 120 VAC (minimum 102 VAC to maximum 132 VAC)

to boiler.

3. Make sure thermostat is calling for heat and contacts (including

appropriate zone controls) are closed. Check for 24 VAC

between thermostat wire nuts and ground.

Troubleshooting sequence:

1. Before proceeding, check for:

•Loose connections, blown fuse or service switch off?

•High limit switch set below boiler water temperature?

•Thermostat set below room temperature?

•Gas not turned on at meter or boiler?

•Incoming gas pressure less than:

5" w.c. for natural gas? 11" w.c. for propane gas?

2. If all of the above check correctly, check gas pressures:

a. With boiler off

•13" w.c. maximum natural or propane gas pressure

upstream of gas valve.

b. With boiler 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 incorrect or gas is not available to boiler,

contact gas supplier to correct before proceeding further.

3. Check pilot operation - Follow “Lighting Instructions”, pages 20

and 21.

•If gas is available and you cannot obtain a pilot flame, try

purging the gas line and cleaning pilot and pilot gas tubing.

Follow “Lighting Instructions” again. If you still cannot obtain

a flame, replace pilot burner and gas tubing. If this does not

allow you to obtain a pilot flame, replace gas valve.

•If you obtain a pilot flame, but pilot will not remain on, replace

thermocouple. If this does not correct problem, replace gas

valve and pilot burner.

•If pilot stays on, but main gas will not come on, proceed to

page 28.

In event of vent damper failure:

Effikal vent damper

If troubleshooting chart recommends replacing actuator and actuator

is not immediately available, damper blade can be fixed in an open

position to allow boiler operation. Manually turning blade can cause

actuator damage. Follow these instructions only in case of no heat

or damper actuator malfunction.

1. Move damper service switch to Hold Damper Open position.

Apply call for heat to boiler. Damper blade should then rotate to

Open position and boiler will fire.

2. If step 1 does not open damper, manually rotate damper blade

to open position using wrench or pliers on flat shaft between

damper and actuator. Boiler will fire. Verify that damper service

switch is in Hold Damper Open position. (Figure 15)

3. Do not leave vent damper permanently in this position. Replace

actuator immediately. If vent damper is left in Open position,

boiler will not operate at published efficiencies.

Johnson Controls vent damper

If troubleshooting chart recommends replacing actuator and actuator

is not immediately available, damper blade can be fixed in an open

position to allow boiler operation. Follow these instructions only in

case of no heat or damper actuator malfunction. See Figure 15.

1. Turn off power to boiler.

Failure to turn off power to boiler can result in severe

personal injury, death or substantial property damage.

2. See vent damper manufacturer’s instructions for procedure to

fix vent damper in open position.

3. Turn on power to boiler.

4. Using wrench or pliers on flat shaft section, manually rotate

damper blade until green light turns on. Boiler will fire. (Figure 15)

5. Do not leave vent damper permanently in this position. Replace

actuator immediately. If vent damper is left in Open position,

boiler will not operate at published efficiencies.

GWA

Gas-Fired Water Boilers – Boiler Manual

11Part Number 670 01 1001 00

Near-boiler piping continued

Figure 7 Piping refrigeration systems

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 7 for typical installation of balancing

valve and check valve.

If system includes radiant heating circuits, provide

piping and controls to regulate the temperature

supplying the radiant circuits. Failure to comply could

result in substantial property damage.

Use Figure 5 or Figure 6 only for systems designed

for return water at least 130 °F. For systems with low

return water temperature possible, such as

converted gravity systems and radiant heating

systems, install bypass piping (see page 12) 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 damage.

Install boiler so that chilled medium is piped in parallel

with heating boiler (Figure 7). Use appropriate valves

to prevent chilled medium from entering boiler. Consult

I=B=R 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 flow control valves or other

automatic 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.

Figure 6 Closed-type expansion tank: Piping to

single-zone system using closed-type

expansion tank. See Table 4 for piping sizes.

Figure 5 Diaphragm- or bladder-type expansion tank:

Piping to single-zone system using

diaphragm-type or bladder-type expansion

tank. See Table 4 for piping sizes.

3 Install water piping continued

GWA

Gas-Fired Water Boilers – Boiler Manual

26 Part Number 670 01 1001 00

10 Service and maintenance continued

❏❏

❏Check/test. . . . . . . . . . continued

Diaphragm- or bladder-type — welded gas tight with a rubber

membrane to separate the tank pressurizing air and the water.

May be located at any point in the system, but most often found

near the boiler.

•Systems with this type of expansion tank require at least

one automatic air vent, preferably located on top of an air

eliminator, as shown in examples in Manual Section 3,

page 10.

2. If relief valve has tended to weep frequently, the expansion tank

may be waterlogged or undersized.

Closed-type tank — tank is most likely waterlogged. Install a

tank fitting if not already installed. Then check fill level per fitting

manufacturer’s instructions. If fill level is correct, check tank

size against manufacturer’s instructions. Replace with a larger

tank if necessary.

Diaphragm- or bladder-type — first, check tank size to be

sure it is large enough for the system. If size is too small, add

additional tank(s) as necessary to provide sufficient expansion.

If tank size is large enough, remove tank from system and

check charge pressure (usually 12 psig for residential

applications). If tank won’t hold pressure, membrane has been

damaged. Replace tank.

Boiler relief valve

1. Inspect the relief valve and lift the lever to verify flow as in the

following warnings, excerpted from a relief valve manufacturer’s

warning label. Before operating any relief valve, ensure that it is

piped with its discharge in a safe area to avoid severe scald

potential. Read Manual Section 3, page 10, before proceeding

further.

2. After following the preceding warning directions, if the relief valve

weeps or will not seat properly, replace the relief valve. Ensure

that the reason for relief valve weeping is the valve and not

over-pressurization of the system due to expansion tank

waterlogging or undersizing.

❏❏

❏Review with owner

1. Review the User’s Information Manual with the owner.

2. Emphasize the need to perform the maintenance schedule

specified in the User’s Information Manual (and in this manual

as well).

3. Remind the owner of the need to call in a licensed contractor

should the boiler or system exhibit any unusual behavior.

4. Remind the owner to follow the proper shutdown procedure

and to schedule an annual start-up at the beginning of the next

heating season.

The boiler contains ceramic fiber and fiberglass

materials. Use care when handling these materials

per instructions on page 23 of this manual. Failure to

comply could result in severe personal injury.

1. Shut down boiler:

•Follow “To Turn Off Gas to Appliance” instructions on boiler

and “Lighting or Operating Instructions”.

•Do not drain boiler unless it will be exposed to freezing

temperatures. If using antifreeze in system, do not drain.

2. Follow shutdown procedure.

3. Remove venting system connection to boiler.

4. Remove top jacket panel. Turn back insulation.

5. Remove flue collector. Clean sealant from assembly and

sections.

6. Remove radiation plates hanging between sections.

7. Remove burners from base. Brush and vacuum burners to

remove all dust and lint. Verify that all burner ports are free of

debris.

8. Place newspapers in base of boiler to collect soot.

9. Clean between sections with wire flue brush.

10. Remove newspaper and soot. Vacuum or brush base and

surrounding area.

11. Reinstall radiation plates.

12. Replace collector box/transition assembly. Seal with sealant.

Obtain gas-tight seal to prevent flue gas spillage and carbon

monoxide emissions, resulting in severe personal injury or death.

13. Replace insulation and jacket top panel.

14. Start up boiler following section 6, pages 15–17 of this manual

and the boiler “Lighting Instructions”, pages 20 and 21.

Excessive sooting indicates improper gas combustion. If found,

check for proper combustion and make any necessary

adjustments.

❏❏

❏Cleaning boiler heating surfaces

Safety relief valves should be reinspected AT LEAST

ONCE EVERY THREE YEARS, by a licensed plumb-

ing contractor or authorized inspection agency, to

ensure that the product has not been affected by

corrosive water conditions and to ensure that the

valve and discharge line have not been altered or

tampered with illegally. Certain naturally occurring

conditions may corrode the valve or its components

over time, rendering the valve inoperative. Such con-

ditions are not detectable unless the valve and its

components are physically removed and inspected.

This inspection must only be conducted by a plumb-

ing contractor or authorized inspection agency — not

by the owner. Failure to reinspect the boiler relief valve

as directed could result in unsafe pressure buildup,

which can result in severe personal injury, death or

substantial property damage.

Following installation, the valve lever must be oper-

ated AT LEAST ONCE A YEAR to ensure that wa-

terways are clear. Certain naturally occurring min-

eral deposits may adhere to the valve, rendering it

inoperative. When manually operating the lever, wa-

ter will discharge and precautions must be taken to

avoid contact with hot water and to avoid water dam-

age. Before operating lever, check to see that a dis-

charge line is connected to this valve directing the

flow of hot water from the valve to a proper place of

disposal otherwise severe personal injury may re-

sult. If no water flows, valve is inoperative. Shut down

boiler until a new relief valve has been installed.

GWA

Gas-Fired Water Boilers – Boiler Manual

12 Part Number 670 01 1001 00

Figure 8 System bypass piping in boiler loop with

separate system circulator, using primary/

secondary piping.

Figure 9 Boiler bypass piping — use only for high

water content systems —DO NOT use for

radiant panel systems.

Near-boiler piping continued

Install all components specified 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.

3 Install water piping continued

System bypass method

1. Apply bypass piping of Figure 8 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 damage

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 temperature

to the boiler enough to prevent condensation of flue gases.

Boiler bypass method

1. Apply bypass piping of Figure 9 to high water content systems,

such as converted gravity systems.

2. The bypass arrangement shown protects the boiler from damage

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 approximately

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 temperature

rise in the boiler that the average temperature will be warm

enough to prevent condensation of flue gases.

GWA

Gas-Fired Water Boilers – Boiler Manual

25Part Number 670 01 1001 00

❏❏

❏Check/test. . . . . . . . . .

Air vents and air elimination

1. Inspect automatic air vents (if used). Also inspect air separators

to ensure they are operational.

2. The cap must be unscrewed one turn to allow air to escape.

3. If the air vent is leaking, remove cap and briefly push valve —

then release to clean the valve seat.

4. Replace cap by twisting all the way onto valve and then

unscrewing one turn.

Limit controls and cutoffs

1. Inspect and test the boiler limit control. Verify operation by turning

control set point below boiler temperature. Boiler should cycle

off. Return dial to original setting.

2. Inspect and test additional limit controls or low water cutoffs

installed on system.

Expansion tank

1. Expansion tanks provide space for water to move in an out as

the heating system water expands due to temperature increase

or contracts as the water cools. Tanks may be open, closed or

diaphragm or bladder type. See Section 3, page 10 of this

manual for suggested locations of expansion tanks and air

eliminators.

Open-type — located above highest radiator or baseboard unit,

usually in the attic or closet. Has a gauge glass and overflow

pipe to a drain.

Closed-type — welded gas tight and located above boiler. Tank

is partially filled with water, leaving an air cushion for expansion.

•Make sure this type of tank is fitted with a tank fitting, such

as the B & G Tank-Trol or Taco Taco-Trol. This fitting reduces

gravity circulation of air-saturated tank water back to the

system and prevents the air from bubbling up through the

water as it returns from the system.

•Do not use automatic air vents in systems with closed-type

tanks. The air will escape from the system instead of

returning to the tank. Eventually, the tank will waterlog and

no longer control pressurization. The boiler relief valve will

weep frequently.

10 Service and maintenance continued

❏❏

❏Check/test. . . . . . . . . .

Gas piping

1. Sniff near floor and around boiler area for any indication of a

gas leak.

2. Test gas piping using bubble test, per Section 4, page 13 of this

manual, if there is any indication of a leak.

Cold fill and operating pressures

1. While the system is cold, note the pressure reading on the boiler

pressure/temperature gauge. Verify that cold fill pressure is

correct.

2. Watch the pressure as the boiler and system heat up to ensure

pressure rise is normal. Too high a rise would indicate a

waterlogged or undersized expansion tank.

❏❏

❏Start-up. . . . . . . . . .

1. Perform start-up procedures Section 6, pages 15–17, including

“Verify operation” of burners and vent damper on page 17.

2. Verify cold fill pressure is correct and that fill system is working

properly.

3. Verify antifreeze level (if used) is at the right concentration and

that inhibitor level is correct.

4. Check gas piping, per Manual Section 4, page 13 and Section

6, page 15, verifying no indications of leakage and all piping

and connections are in good condition.

5. Read the “Lighting or Operating Instructions” (Manual Section 9,

pages 20 and 21 or Control Supplement) applying to the boiler.

6. Start the boiler following the “Lighting or Operating Instructions”

(Manual Section 9, pages 20 and 21 or Control Supplement).

Oiled-bearing circulators

1. The circulator shipped with the GWA boiler is water-lubricated.

No oiling is required.

2. Check other circulators in the system. Oil any circulators

requiring oil, following circulator manufacturer’s instructions.

Over-oiling will damage the circulator.

❏❏

❏Service. . . . . . . . . .

GWA

Gas-Fired Water Boilers – Boiler Manual

13Part Number 670 01 1001 00

Table 5 Pipe capacity for 0.60 specific gravity natural gas

4 Install gas piping

Natural Gas:

1. See Table 5 for pipe length and diameter. Base on rated

boiler input (divide by 1,000 to obtain cubic feet per hour).

Table 5 is only for gas with specific 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 standard 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

1. Remove jacket front panel and see Figure 10 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 floor, 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

requirements.

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 flame —

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 flow.

Failure to apply pipe dope as described in this manual

can result in severe personal injury, death or

substantial property damage.

Connecting gas supply piping to boiler

Figure 10 Gas supply piping

GWA

Gas-Fired Water Boilers – Boiler Manual

24 Part Number 670 01 1001 00

The boiler should be inspected and started annually,

at the beginning of the heating season, only by a

qualified service technician. In addition, the

maintenance and care of the boiler designated in

Table 6, page 22 and explained on the following pages

must be performed to assure maximum boiler

efficiency and reliability. Failure to service and

maintain the boiler and system could result in

equipment failure.

Electrical shock hazard — Turn off power to the boiler

before any service operation on the boiler except as

noted otherwise in this manual. Failure to turn off

electrical power could result in electrical shock,

causing severe personal injury or death.

The boiler contains ceramic fiber and fiberglass

materials. Use care when handling these materials

per instructions on page 23 of this manual. Failure to

comply could result in severe personal injury.

❏❏

❏Inspect . . . . . . . . . .

Reported problems

Inspect any problems reported by owner and correct before

proceeding.

Boiler area

1. Verify that boiler area is free of any combustible materials,

gasoline and other flammable vapors and liquids.

2. Verify that boiler area (and air intake) is free of any of the

contaminants listed in Table 2 on page 5 of this manual. If any of

these are present in the boiler intake air vicinity, they must be

removed. If they cannot be removed, install combustion air piping

to the boiler in accordance with national, provincial or local

codes.

Air openings

1. Verify that combustion and ventilation air openings to the boiler

room and/or building are open and unobstructed. Check

operation and wiring of automatic combustion air dampers, if

used.

2. Verify that boiler vent discharge and air intake are clean and

free of obstructions.

Flue gas vent system

1. Visually inspect entire flue gas venting system for blockage,

deterioration or leakage. Repair any joints that show signs of

leakage in accordance with vent manufacturer’s instructions.

2. Verify that masonry chimneys are lined, lining is in good

condition, and there are not openings into the chimney.

Failure to inspect for the above conditions and have

them repaired can result in severe personal injury or

death.

Pilot and main burner flames

1. Visually inspect pilot burner and main burner flames as directed

under Section 6, page 17 of this manual.

10 Service and maintenance continued

Water piping

1. Check the boiler interior piping and all system piping for signs

of leaks.

2. Repair any leaks before proceeding.

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 or boiler 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.

Leaking water may also cause severe property

damage.

❏❏

❏Inspect . . . . . . . . . .

Boiler heating surfaces

1. Disconnect the vent pipe at the boiler draft hood and remove

draft hood after turning off power to the boiler.

2. Use a bright light to inspect the boiler flue collector and heating

surfaces.

3. If the vent pipe or boiler interior surfaces show evidence of

soot, follow “Cleaning boiler heating surfaces” in this manual

section, page 26. Remove the flue collector and clean the boiler

if necessary after closer inspection of boiler heating surfaces.

4. If there is evidence of rusty scale deposits on boiler surfaces,

check the water piping and control system to make sure the

boiler return water temperature is properly maintained (per this

manual).

5. Reconnect vent and draft hood. Replace all boiler components

before returning to service.

6. Check inside and around boiler for evidence of any leaks from

the boiler. If found, locate source of leaks and repair.

Burners and base

1. After turning off power to the boiler, remove the jacket door and

base access panel (Figure 17, item 4, page 30).

2. Inspect burners and all other components in the boiler base.

3. If burners must be cleaned, raise rear of each burner to release

from support slot, slide forward and remove. Then brush and

vacuum the burners thoroughly, making sure all ports are free

of debris. Carefully replace all burners, making sure burner with

pilot bracket is replaced in its original position and all burners

are upright (ports up).

4. Inspect the base insulation.

The boiler contains ceramic fiber and fiberglass

materials. Use care when handling these materials

per instructions on page 23 of this manual. Failure to

comply could result in severe personal injury.

a. Verify that the insulation is intact and secure against all four

sides of the base.

If insulation is damaged or displaced, do not operate

the boiler. Replace or reposition insulation as

necessary. Failure to replace damaged insulation can

result in a fire hazard, causing severe personal injury,

death or substantial property damage.

GWA

Gas-Fired Water Boilers – Boiler Manual

14 Part Number 670 01 1001 00

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, provincial

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, except spill switch

and vent damper. See wiring diagram on page 19 for standing pilot

ignition boiler or Control Supplement for spark-ignited pilot boiler.

Circulator is shipped loose, but wiring harness is pre-attached to

the boiler. Connect wires in circulator junction box.

Figure 11 Field wiring connections — service switch and thermostat (or end switch) provided by installer

5 Field wiring

Thermostat

1. Connect thermostat as shown on wiring diagram on boiler.

2. Install on inside wall away from influences of drafts, hot or cold

water pipes, lighting fixtures, television, sunrays or fireplaces.

3. If thermostat has a heat anticipator, set heat anticipator in

thermostat to match power requirements of equipment

connected to it. If connected directly to boiler, set for 0.4 amps.

For other devices, see manufacturer’s specifications. Wiring

diagram on boiler gives setting for control module and gas valve.

Also see instructions with thermostat.

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.

Junction box (furnished)

1. Connect 120 VAC power wiring (Figure 11).

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.

GWA

Gas-Fired Water Boilers – Boiler Manual

23Part Number 670 01 1001 00

Handling ceramic fiber and fiberglass materials

REMOVAL OF COMBUSTION CHAMBER LINING OR BASE PANELS

The combustion chamber lining or base insulation panels in this product contain ceramic fiber materials. Ceramic

fibers can be converted to cristobalite in very high temperature applications. The International Agency for Research

on Cancer (IARC) has concluded, "Crystalline silica inhaled in the form of quartz or cristobalite from occupational

sources is carcinogenic to humans (Group 1).":

■Avoid breathing dust and contact with skin and eyes.

•Use NIOSH certified dust respirator (N95). This type of respirator is based on the OSHA requirements for

cristobalite at the time this document was written. Other types of respirators may be needed depending on

the job site conditions. Current NIOSH recommendations can be found on the NIOSH web site at http://

www.cdc.gov/niosh/homepage.html. NIOSH approved respirators, manufacturers, and phone numbers are

also listed on this web site.

•Wear long-sleeved, loose fitting clothing, gloves, and eye protection.

■Apply enough water to the combustion chamber lining or base insulation to prevent airborne dust.

■Remove combustion chamber lining or base insulation from the boiler and place it in a plastic bag for disposal.

■Wash potentially contaminated clothes separately from other clothing. Rinse clothes washer thoroughly.

NIOSH stated First Aid.

■Eye: Irrigate immediately

■Breathing: Fresh air.

REMOVAL OF FIBERGLASS WOOL — OR —

INSTALLATION OF FIBERGLASS WOOL, COMBUSTION CHAMBER LINING OR BASE

PANELS:

This product contains fiberglass jacket insulation and ceramic fiber materials in combustion chamber lining or base

panels in gas fired products. Airborne fibers from these materials have been listed by the State of California as a

possible cause of cancer through inhalation.

■Avoid breathing dust and contact with skin and eyes.

•Use NIOSH certified dust respirator (N95). This type of respirator is based on the OSHA requirements for

fiberglass wool at the time this document was written. Other types of respirators may be needed depending

on the job site conditions. Current NIOSH recommendations can be found on the NIOSH web site at http://

www.cdc.gov/niosh/homepage.html. NIOSH approved respirators, manufacturers, and phone numbers are

also listed on this web site.

•Wear long-sleeved, loose fitting clothing, gloves, and eye protection.

■Operations such as sawing, blowing, tear out, and spraying may generate airborne fiber concentration requiring

additional protection.

■Wash potentially contaminated clothes separately from other clothing. Rinse clothes washer thoroughly.

NIOSH stated First Aid.

■Eye: Irrigate immediately

■Breathing: Fresh air.

10 Service and maintenance continued

GWA

Gas-Fired Water Boilers – Boiler Manual

15Part Number 670 01 1001 00

Check for gas leaks

Before starting the boiler, and during initial

operation, smell near the floor and around the boiler

for gas odorant or any unusual odor. Do not

proceed with start-up if there is any indication of a

gas leak. 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 gas can accumulate at floor level. Smell near

the floor for the gas odorant or any unusual odor. If you

suspect a leak, do not attempt to light the pilot.

•Use caution when attempting to light the propane pilot.

This should be done by a qualified service technician,

particularly if pilot outages are common.

•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 propane supplier regarding installation

of a gas leak detector. There are some products on the

market intended for this purpose. Your supplier may be

able to suggest an appropriate device.

6 Start-up

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

with each application. Typical cold water fill pressure for a

residential system is 12 psi.

3. Purge air from system:

a. Connect a hose to purge valve or valves, if installed.

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-fill valve on cold water makeup line.

e. Open purge valve.

f. One zone at a time, open the isolation valves. Allow water

to run through the zone, pushing out the air. Run until no

noticeable air flow is present. Close the zone isolation valves

and proceed with the next zone. Follow this procedure until

all zones are purged.

g. Close the quick-fill water valve and purge valve and remove

the hose. Open all isolation valves. Watch that system

pressure rises to correct cold-fill pressure.

h. After the system has operated for a while, eliminate any

residual air by using the manual air vents located throughout

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 when water squirts out. Repeat with remaining

vents.

4. Open automatic air vent (diaphragm-type or bladder-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 filling the boiler and system with water, inspect all piping

throughout the system for leaks. If found, repair immediately. Repeat

this inspection after the boiler has been started and the 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.

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

in sections, reducing heat transfer, 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 quantity according to system water

content. Boiler water content is listed on page 35. Remember

to include expansion tank water content.

2. Follow antifreeze manufacturer's instructions.

3. A 50% solution of propylene glycol/water provides maximum

protection to about -30 °F.

4. Local codes may require back flow preventer or actual

disconnect from city water supply.

5. When using antifreeze in a system with automatic fill, install

a water meter to monitor water makeup. Glycol will leak before

the water begins to leak, causing glycol level to drop. Added

water will dilute the antifreeze, reducing the freeze protection

level.

Inspect base insulation

Check to make sure insulation is secure against all four sides of

the base. If insulation is damaged or displaced, do not operate 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 damage.

The boiler contains ceramic fiber and fiberglass

materials. Use care when handling these materials

per instructions on page 23 of this manual. Failure to

comply could result in severe personal injury.

GWA

Gas-Fired Water Boilers – Boiler Manual

22 Part Number 670 01 1001 00

Follow the “Service and maintenance” procedures given throughout this manual and in component literature shipped with

the boiler. See “Read this first” on page 2. Failure to perform the service and maintenance could result in damage to the boiler

or system. Failure to follow the directions in this manual and component literature could result in severe personal injury,

death or substantial property damage.

Table 6 Service and maintenance schedules (service technician and owner)

10 Service and maintenance

Service technician

(see following pages for instructions) Owner maintenance

(see User’s Information Manual for instructions)

ANNNUAL START-UP

❏

Inspect:

• Reported problems

• Boiler area

• Air openings

• Flue gas vent system

• Pilot and main burner flames

• Water piping

• Boiler heating surfaces

• Burners, base and inlet air box

❏

Service:

• Oiled-bearing circulators

❏

Start-up:

• Perform start-up per manual

❏

Check/test:

• Gas piping

• Cold fill and operating pressures

• Air vents and air elimination

• Limit controls and cutoffs

• Expansion tank

• Boiler relief valve

❏

Review:

• Review with owner

❏ Daily • Check boiler area

• Check boiler pressure/

temperature gauge

• Check air openings

❏ Monthly • Check boiler piping

• Check venting system

• Check boiler relief valve

• Check automatic air vents (if used)

• Check pilot and main burner flames

❏ Periodically • Test low water cutoff (if used)

❏ Every 6 months • Operate relief valve

❏ End of season • Shut down procedure

GWA

Gas-Fired Water Boilers – Boiler Manual

16 Part Number 670 01 1001 00

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

severe 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

“Check for gas leaks”, page 15.

5. Verify operation using procedures below. Perform “Checkout

procedure”, page 18, and fill 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

“Troubleshooting”, Section 11, page 27.

6 Start-up continued

Operate boiler

DO NOT proceed with boiler operation unless boiler

and system have been filled with water and all

instructions and procedures of previous manual

sections have been completed. Failure to do so could

result in severe personal injury, death or substantial

property damage. Before starting the boiler . . .

•See pages 20 and 21, for standing pilot boiler “Lighting

Instructions”, or the Control Supplement for spark-

ignited pilot “Operating Instructions”.

•Verify the boiler and system are full of water (or glycol/

water mixture, if used).

•Verify the “Preparation” procedures of page 15 have

been completed.

Start the boiler

Follow the “Lighting or Operating Boiler Instructions” from:

•Standing pilot boilers — Manual pages 20 and 21.

•Spark-ignited pilot boilers — See Control Supplement.

Remove boiler jacket door and note the gas valve manufacturer

and model number.

See either page 20 or page 21, depending on gas valve installed in

boiler. Use only the “Lighting Instruction” which applies to this gas

valve. (The “Lighting Instruction” label on the boiler provides the

same information.)

If boiler fails to start, see “If boiler doesn’t start . . . Check for:” on

this page.

GWA

Gas-Fired Water Boilers – Boiler Manual

21Part Number 670 01 1001 00

9 Lighting Instructions — GWA standing pilot boilers

Robertshaw 7200 gas valve

FOR YOUR SAFETY READ BEFORE LIGHTING

If you do not follow these instructions exactly, a fire or explosion may result causing

property damage, personal injury or loss of life.

1. Set the thermostat to lowest setting.

2. Turn off all electric power to the appliance if service is to be

performed.

3. Remove front panel.

4. Depress and move selector arm left to OFF.

5. Replace front panel.

LIGHTING INSTRUCTIONS

WHAT TO DO IF YOU SMELL GAS

•Do not try to light any appliance.

•Do not touch any electric switch; do not use any phone in

your building.

•Immediately call your gas supplier from a neighbor’s

phone. Follow the gas supplier’s instructions.

•If you cannot reach your gas supplier, call the fire

department.

A. This appliance has a pilot, which must be

lighted by hand. When lighting the pilot, follow

these instructions exactly.

B. Before LIGHTING, smell all around the

appliance area for gas. Be sure to smell next

to the floor because some gas is heavier than

air and will settle on the floor. See below.

C. Use only your hand to push down the reset button or turn the gas control

knob. Never use tools. If the knob or reset button will not operate by hand,

don't try to repair it, call a qualified service technician. Force or attempted

repair may result in a fire or explosion.

D. Do not use this appliance if any part has been under water. Immediately call

a qualified service technician to inspect the appliance and to replace any

part of the control system and any gas control, which has been under water.

1. Stop! Read the safety information above on this label.

2. Set the thermostat to lowest setting.

3. When equipped with Effikal vent damper Model RVGP, place

service switch in Hold Damper Open position.

4. Turn off all electrical power to the appliance.

5. When equipped with Johnson Controls vent damper Model

M35, manually rotate damper blade in direction of arrow to

Open position indicated on damper assembly.

6. Depress and move selector arm left to OFF.

7. When equipped with vent damper, verify damper blade is in

full open position.

8. Wait five (5) minutes to clear out any gas. Then smell for

gas, including near the floor. If you smell gas, STOP! Follow

"B" in the safety information above. If you don't smell gas,

go to the next step.

9. Remove access panel located above burners.

10. Find pilot — follow metal tube from gas control.

The pilot is between two burners behind the

access panel.

11. Move selector arm on gas control right

to SET position.

12. Hold selector arm in SET position and immediately light the

pilot with a match. Continue to hold selector arm to SET for

about one-half (1/2) minute after the pilot is lit.

13. Release selector arm. If pilot does not remain lit, repeat steps

6 through 13.

•If the pilot will not stay lit after several tries, move selector

arm left to OFF and call your service technician or gas

supplier.

14. Replace access panel.

15. Turn selector arm left to ON.

16. Turn on all electric power to the appliance.

17. When equipped with Effikal vent damper, place service

switch in Automatic Operation position.

18. Set thermostat to desired setting.

19. Replace front panel.

TO TURN OFF GAS TO THE APPLIANCE

GWA

Gas-Fired Water Boilers – Boiler Manual

17Part Number 670 01 1001 00

Check the pilot ignition system used for the boiler.

The boiler model suffix will contain an “S” for standing

pilot or an “I” for spark-ignited pilot. See Section 9,

pages 20 and 21, for standing pilot boiler “Lighting

Instructions”, or the Control Supplement for spark-

ignited pilot “Operating Instructions”.

Figure 12 Typical pilot burner flame

Verify operation

Check vent damper operation

1. Raise room thermostat to call for heat — Vent damper actuator

will slowly open vent damper.

2. When vent damper is fully open — Main gas valve will open

and main burners will ignite. (Spark-ignited pilot controls will

first light pilot, then allow main burners to ignite.)

Vent damper must be fully open before main burners

light. If vent damper does not fully open, flue products

such as carbon monoxide will escape into house,

causing severe personal injury or death.

3. Lower thermostat setting — Main burner flames will go out, then

vent damper will close.

4. Repeat Steps 2 through 4 several times to verify operation.

5. Return thermostat to normal setting.

6. Set thermostat heat anticipator setting indicated on wiring

diagram.

Check venting system operation

1. With boiler firing, hold a candle or match below lower edge of

draft hood “skirt.” If flame does not blow out, but burns

undisturbed, the vent system is working properly. If flame blows

out or flickers severely, the vent system must be checked for

obstructions or other causes of improper venting.

Figure 13 Typical main burner flame

Check burner flames — Main burner

Proper main burner flame (see Figure 13):

1. Yellow-orange streaks may appear (caused by dust).

Improper main burner flame:

1. Overfired — Large flames.

2. Underfired — Small flames.

3. Lack of primary air — Yellow tipping on flames (sooting will

occur).

Check burner flame — Pilot burner

Proper pilot flame (see Figure 12):

1. Blue flame.

2. Inner cone engulfing thermocouple (standing pilot) or pilot flame

sensor (spark-ignited pilot).

3. Thermocouple or pilot flame sensor glowing cherry red.

Improper pilot flame:

1. Overfired — Large flame lifting or blowing past pilot flame

sensor.

2. Underfired — Small flame. Inner cone not engulfing pilot flame

sensor.

3. Lack of primary air — Yellow flame tip.

4. Incorrectly heated pilot flame sensor.

6 Start-up continued

GWA

Gas-Fired Water Boilers – Boiler Manual

20 Part Number 670 01 1001 00

9 Lighting Instructions — GWA standing pilot boilers

Honeywell VR8200/VR8300 gas valve

If you do not follow these instructions exactly, a fire or explosion may result causing

property damage, personal injury or loss of life.

A. This appliance has a pilot, which must be

lighted by hand. When lighting the pilot, follow

these instructions exactly.

B. Before LIGHTING, smell all around the

appliance area for gas. Be sure to smell next

to the floor because some gas is heavier than

air and will settle on the floor. See below.

C. Use only your hand to push down the reset button or turn the gas control

knob. Never use tools. If the knob or reset button will not operate by hand,

don't try to repair it, call a qualified service technician. Force or attempted

repair may result in a fire or explosion.

D. Do not use this appliance if any part has been under water. Immediately call

a qualified service technician to inspect the appliance and to replace any

part of the control system and any gas control, which has been under water.

•Do not try to light any appliance.

•Do not touch any electric switch; do not use any phone in

your building.

•Immediately call your gas supplier from a neighbor’s phone.

Follow the gas supplier’s instructions.

•If you cannot reach your gas supplier, call the fire department.

1. Stop! Read the safety information above on this label.

2. Set the thermostat to lowest setting.

3. When equipped with Effikal vent damper Model RVGP, place

service switch in Hold Damper Open position.

4. Turn off all electrical power to the appliance.

5. When equipped with Johnson Controls vent damper Model

M35, manually rotate damper blade in direction of arrow to

Open position indicated on damper assembly.

6. Turn gas control knob clockwise to OFF.

7. When equipped with vent damper, verify damper blade is in

full open position.

8. Wait five (5) minutes to clear out any gas. Then smell for

gas, including near the floor. If you smell gas, STOP! Follow

"B" in the safety information above. If you don't smell gas,

go to the next step.

9. Remove access panel located above burners.

10. Find pilot — follow metal tube from gas control.

The pilot is between two burners behind the

access panel.

11. Turn gas control knob counterclockwise to

PILOT.

12. Push in red reset button and hold. Immediately light the pilot

with a match. Continue to hold reset button in for about one

(1) minute after the pilot is lit.

13. Release reset button. Pilot should remain lit. If pilot goes out,

repeat steps 6 through 13.

•If reset button stays depressed after release, stop and

immediately call your service technician or gas supplier.

•If the pilot will not stay lit after several tries, turn the gas control

knob clockwise to OFF and call your service technician

or gas supplier.

14. Replace access panel.

15. Turn gas control knob counterclockwise to ON.

16. Turn on all electric power to the appliance.

17. When equipped with Effikal vent damper, place service switch

in Automatic Operation position.

18. Set thermostat to desired setting.

19. Replace front panel.

1. Set the thermostat to lowest setting.

2. Turn off all electric power to the appliance if service is to be

performed.

3. Remove front panel.

4. Turn gas control knob clockwise to OFF.

5. Replace front panel.

FOR YOUR SAFETY READ BEFORE LIGHTING

LIGHTING INSTRUCTIONS

TO TURN OFF GAS TO THE APPLIANCE

WHAT TO DO IF YOU SMELL GAS

GWA

Gas-Fired Water Boilers – Boiler Manual

18 Part Number 670 01 1001 00

7 Checkout procedure

❏Boiler and heat distribution units filled 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 orifices installed? See Table 3,

page 6, to check size and fuel type.

Correctly sized manifold orifices must be used.

Failure to do so will cause severe personal injury,

death or substantial property damage.

❏Followed “Lighting or Operating Instructions” on boiler or in

Manual Section 9 or Control Supplement for proper start-up?

❏Proper burner flame observed? See “Verify operation”, Manual

Section 6, page 17.

❏Test limit control — While burners are operating, move indicator

on limit control below actual boiler water temperature. Burners

should go off while circulator continues to operate. Raise setting

on limit control above boiler water temperature and burners

should reignite.

❏Test additional field-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.

❏Button on spill switch pushed in?

❏Test ignition system safety device:

a. Standing pilot — Turn gas cock knob to PILOT position

and extinguish pilot flame. Pilot gas flow should stop in less

than 3 minutes. Put system back into operation (see

Section 6, pages 15-17).

b. Spark-ignited pilot — Connect manometer to outlet side

of gas valve. Start boiler, allowing for normal start-up cycle

to occur and main burners 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.

❏For multiple zones, adjust flow so it is about the same in

each zone.

❏Verify thermostat heat anticipator (if available) set properly?

See “Field wiring”, Manual Section 5, page 14, “Thermostat”.

❏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.

❏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

rating label.

oInstallation instructions have been followed.

oCheckout sequence has been performed.

oAbove information is certified to be correct.

oInformation received and left with owner/maintenance person.

Installation and service certificate

❏Check manifold gas pressure by connecting manometer to

downstream test tapping on main gas valve. Manifold pressure

for natural gas should be 3.5" w.c. and for propane gas should

be 10" w.c.

❏Observe several operating cycles for proper operation.

❏Set room thermostat to desired room temperature.

❏Fill in Installation and service certificate below?

❏Review all instructions shipped with this boiler with owner or

maintenance person. Return instructions to envelope and give

to owner or place in pocket inside front panel in boiler.

Boiler model _______________________________________________________________ Series ____________

CP number _______________________________________ Date installed _________________________________

Measured Btuh input ____________

Installer _______________________ ______________________________ ____________________________

(company) (address) (phone)

_____________________________________

(installer’s signature)

GWA

Gas-Fired Water Boilers – Boiler Manual

19Part Number 670 01 1001 00

Figure 14 Wiring diagram — Standing pilot system

8 Sequence of operation — standing pilot boilers

Follow all procedures given in this manual and “Lighting Instructions” when

operating the boiler. Failure to do so could result in severe personal injury,

death or substantial property damage.

1. Standby mode: After pilot is manually lighted, the gas valve provides pilot gas and

maintains pilot as long as the thermocouple is satisfied. If thermocouple signal drops

for any reason, pilot must be manually lighted, following the “Lighting Instructions” in

this manual and on boiler. Vent damper will remain closed until a call for heat.

2. Call for heat: When thermostat circuit closes, the boiler circulator and vent damper

are energized. The vent damper drives open. When the vent damper is fully open, its

end switch energizes the main gas valve. This provides gas to the main burners.

Burners remain ignited until thermostat circuit or limit circuit opens. Burners and

circulator are de-energized when call for heat stops. Burners are de-energized, but

circulator remains on, if the limit circuit opens.

3. Limit operation: When a limit control opens, the main gas valve is de-energized, but

circulator continues to run. When the limit circuit closes again, the main gas valve is

energized if there is still a call for heat.

4. Thermostat heat anticipator: Set heat anticipator as shown on wiring diagram,

Figure 14.