GWS Gas-Fired Water Boilers User manual

Part Number 550-110-732/0703
Contents Page
1 Prepare boiler location ........................................................ 2
2 Prepare boiler ..................................................................... 8
3 Install water piping .............................................................. 9
4 Venting and combustion air ............................................... 12
5 Gas piping ........................................................................ 12
6 Field wiring ....................................................................... 13
7 Start-up ............................................................................ 14
8 Checkout procedure ......................................................... 16
9 Sequence of operation ...................................................... 17
10 Operating instructions ....................................................... 19
11 Service and maintenance ................................................. 20
12 Troubleshooting ................................................................ 25
13 Replacement parts ........................................................... 33
14 Dimensions ...................................................................... 38
15 Ratings ............................................................................. 39
Boiler Manual
GWS
Gas-Fired Water Boilers
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 16.
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

GWS Gas-Fired Water Boilers – Boiler Manual
2Part Number 550-110-732/0703
Codes & checklist
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!
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 GWS 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 (when required) in boiler water causing system
and boiler to freeze and leak.
The boiler contains ceramic fiber and
fiberglass materials. Use care when handling
these materials per instructions on page 21
of this manual. Failure to comply could result
in severe personal injury.
Failure to adhere to the guidelines below can
result in severe personal injury, death or
substantial property damage.

3Part Number 550-110-732/0703
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1 Prepare boiler location continued
Service clearances
1. Provide minimum clearances for cleaning and servicing the
boiler and for access to controls and components as listed in
Table 1 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.
Clearances
Flooring and foundation
Flooring
The GWS 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 2, below, for minimum foundation dimensions.
Residential garage installations
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. Vent pipe must be at least 2 inches from combustible material
except where otherwise noted in GWS Venting Manual.
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 2 Minimum foundation size
Boiler
model
Minimum
foundation
length
Minimum
foundation
width
GWS-063 25" 15"
GWS-095 25" 18"
GWS-127 25" 21"
GWS-158 25" 24"
Figure 1 Minimum clearances in small spaces
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"
Table 1 Minimum service clearances

GWS Gas-Fired Water Boilers – Boiler Manual
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1 Prepare boiler location continued
GWS special vent system required
Vent system
GWS boilers require a special vent system, designed for
pressurized venting. Model GWS-063 is rated ANSI Z21.13
Category IV (pressurized vent, likely to condense in the vent).
Models GWS-095, -127 and -158 are rated Z21.13 Category III
(pressurized vent).
You may use any of the vent systems covered in GWS Venting
Manual included in the boiler envelope assembly. The GWS vent
starter is a special item, designed only for GWS boilers, available
from each vendor. Do not attempt to connect the vent to a GWS
boiler with any other means.
DO NOT mix components from different systems.
The vent system could fail, causing leakage of flue
products into the living space.
Vent termination and combustion air supply
GWS boilers may be vented through the roof or through a side wall.
Follow the appropriate instructions in the GWS Venting Manual for
the vent system chosen. The maximum vent length depends on
boiler size. Refer to the GWS Venting Manual to determine
acceptable vent length.
Combustion air for GWS boilers may be from inside or ducted
directly to the boiler from outside. For outside air (direct vent
installation), two options are available for the flue/air termination.
The air supply must ALWAYS terminate at the same location as
the flue, using either:
1. Vertical direct vent installation — Obtain the Through-Roof or
Through-Unused Chimney Termination Kit. Refer to GWS
Venting Manual, packed with the kit and to the vent
manufacturer’s instructions for the vent material chosen.
2. Sidewall direct vent installation — Use the Vent/Air Intake
Termination Kit shipped with the boiler. Refer to GWS Venting
Manual shipped with the boiler.
Failure to follow all instructions can result in flue gas
spillage and carbon monoxide emissions, causing
severe personal injury or death.
Do not install the GWS into a common vent with any
other appliance. This will cause flue gas spillage or
appliance malfunction, resulting in possible severe
personal injury, death or substantial property damage.
Inspect existing chimney before installing boiler.
Failure to clean or replace perforated pipe or tile lining
will cause severe personal injury or death.
GWS boilers can be either direct-vent vented or
direct-exhaust vented.They cannot be chimney-draft
vented. See GWS Venting Manual for detailed
installation instructions.
If you are removing an existing boiler from a shared
venting system, the new GWS boiler cannot share
the vent system. You must test each appliance
remaining on the common vent system individually
to verify the vent system still operates adequately.
Follow guidelines below.
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.
Vent system

5Part Number 550-110-732/0703
GWS Gas-Fired Water Boilers – Boiler Manual
Table 3 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 3 for products and areas which may cause contaminated
combustion air.
Air contamination
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

GWS Gas-Fired Water Boilers – Boiler Manual
6Part Number 550-110-732/0703
Air openings
Using inside air — direct exhaust venting
The GWS boiler can use inside air if no contaminants are present
in the boiler space. If contaminants are likely to be present, install
the GWS boiler as a direct vent appliance, using the appropriate
instructions in the GWS Venting Manual and the instructions in this
manual.
Using outside air — direct venting
Combustion air can be ducted directly from outside to the GWS
boiler air intake fitting.This method is defined as direct vent (also
referred to as sealed combustion). Refer to the appropriate
instructions in the GWS Venting Manual and the instructions in this
manual.Two options are available: sidewall or vertical direct vent.
Each requires a special vent component kit.
Sizing air openings
Air openings provide for ventilation (as well as combustion air) to
prevent overheating of the boiler controls and boiler space. Air is
also needed for other appliances located in the same space.
Use Figure 2, page 7, selecting the appropriate installation conditions.
Note that the sizing given in Figure 2 applies only to GWS
installations with clearances no smaller than shown in Table 1, page
3 of this manual. For smaller clearances, regardless of how the air
openings are arranged, two openings providing free area of 1 square
inch per 1,000 Btuh input of all appliances in the space are required.
Air openings must be sized to handle all appliances
and air movers (exhaust fans, etc.) using the air
supply.
The sizing given in Figure 2 is based on the National Fuel Gas
Code, ANSI Z223.1, allowing adequate air opening for gravity-vented
gas appliances. The air openings recommended in Figure 2 will
allow adequate ventilation and combustion air provided the boiler
room is not subjected to negative pressure due to exhaust fans or
other mechanical ventilation devices. Refer to the National Fuel
Gas Code for dealing with other conditions.
Louver allowance
The free area of openings means the area after reduction for any
installed louvers or grilles. Be sure to consider this reduction when
sizing the air openings.
Special considerations
Tight construction
ANSI Z223.1 defines unusually tight construction where:
a. Walls and ceilings exposed to the outside atmosphere have a
continuous water vapor retarder with a rating of 1 perm or less
with openings gasketed, and . . .
b. Weather-stripping has been added on openable windows and
doors, and . . .
c. Caulking or sealants are applied to areas such as joints around
windows and door frames, between sole plates and floors,
between wall-ceiling joints, between wall panels, at penetrations
for plumbing, electrical, and gas lines, and in other openings.
For buildings with such construction, provide air openings into the
building from outside, sized per the appropriate case in Figure 2.
Exhaust fans and air movers
The appliance space must never be under a negative pressure,
unless the appliances are installed as direct vent. 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.
1 Prepare boiler location continued

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GWS Gas-Fired Water Boilers – Boiler Manual
Figure 2 Provide minimum air openings for GWS boiler installations based on following:
1 Prepare boiler location continued

GWS Gas-Fired Water Boilers – Boiler Manual
8Part Number 550-110-732/0703
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 GWS 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 18, item 3, page 36. 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 18, item 2, page 36. (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.)
Fill and pressure test
1. Open the shutoff valves you installed on supply and return
connections.
Pressure test
2. Slowly open boiler drain valve and fresh water supply to 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 and valves unless they will remain for use in
the system piping.
4. Remove plug from relief valve tapping. See Section 3, page 9,
to replace relief valve.
2 Prepare boiler
Table 4 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.
Inspect orifices and burners; connect air adapter
1. Remove front jacket door. Remove air adapter fitting from air
inlet hose (see Figure 17, page 35, items 9 and 10) and screw
into opening on jacket top. Reconnect air hose to bottom of air
adapter fitting. Remove inlet air box top panel. (See Figure 16,
item 13, page 34).
2. Check for correctly-sized manifold orifices. See Table 4 for sizing.
(The orifice size is stamped on the orifice spud barrel.)
Placement and setup
Correctly-sized manifold orifices must be used.
Failure to do so will result in severe personal injury,
death or substantial property damage.
3. Reinstall inlet air box top panel and jacket door.
Do not operate boiler without inlet air box top panel
secured in place. Failure to comply could result in
severe personal injury, death or substantial property
damage.

9Part Number 550-110-732/0703
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Table 5 Water pipe size (based on 20 °F rise)
3 Install water piping
Expansion tank
Diaphragm- or bladder-type expansion tank — Figure 3,
page 10
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 4, page 10
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.
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 18 for wiring.
A low water cutoff device is required when boiler is installed above
radiation level or by certain state or local codes or insurance
companies. Use low water cutoff designed for water installations.
Electrode probe-type is recommended. Purchase and install in tee
in supply piping above boiler.
Use backflow check valve in cold water supply if required by local
codes.
See Figure 3 (diaphragm-type or bladder-type expansion tank) or
Figure 4 (closed-type expansion tank) on page 10, and Table 5, for
near-boiler and single-zone systems designed for return water at
least 130 °F.
See page 9 for multiple zone systems.
See page 10 for boilers used with refrigeration systems.
Near-boiler piping
Water piping — multiple zone systems
Install system piping using either circulator zoning or zone valve
zoning. Install expansion tank on suction side of system pump.
Always connect fill line only at the expansion tank — never at
another point in the system.
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.
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 Figures 3 and 4, page 10, 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.
Near-boiler piping continued
Boiler
model
number
To
system
From
system
GWS-063 1" 1"
GWS-095 1" 1"
GWS-127 1" 1"
GWS-158 1¼" 1¼"

GWS Gas-Fired Water Boilers – Boiler Manual
10 Part Number 550-110-732/0703
Figure 3 Diaphragm- or bladder-type expansion tank:
Piping to single-zone system using
diaphragm-type or bladder-type expansion
tank. See Table 5, page 9, for piping sizes.
Figure 4 Closed-type expansion tank: Piping to
single-zone system using closed-type
expansion tank. See Table 5, page 9, for
piping sizes. Figure 5 Piping refrigeration systems
3 Install water piping continued
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 5 for typical installation of balancing
valve and check valve.
Install boiler so that chilled medium is piped in parallel
with heating boiler. 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.
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 3 or Figure 4 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 11) 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.

11Part Number 550-110-732/0703
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Figure 6 System bypass piping in boiler loop with
separate system circulator, using primary/
secondary piping
Figure 7 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 6 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 7 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.

GWS Gas-Fired Water Boilers – Boiler Manual
12 Part Number 550-110-732/0703
Figure 8 Gas supply piping
Table 6 Pipe capacity for 0.60 specific gravity natural gas
1. Remove jacket front panel and see Figure 8 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.
Natural Gas:
1. See Table 6 for pipe length and diameter. Base on rated
boiler input (divide by 1,000 to obtain cubic feet per hour).
Table 6 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
4 Venting and combustion air
GWS Boiler must be vented and supplied with combustion and ventilation air
as described in GWS Venting Manual, packed in envelope assembly with
boiler, and Section 1 of this manual, page 4.Failure to do so will cause severe
personal injury or death.
Use direct vent (sealed combustion) if combustion air quality cannot be
assured to be free of contaminants. Refer to Table 3, on page 5, for a list of
potential contaminants and locations likely to contain them. Operating the
boiler with contaminated air will damage the boiler sections and vent, resulting
in possible boiler failure or leakage of flue products, causing severe personal
injury, death or substantial property damage.
Install vent piping and air piping (if used)
per appropriate instructions in the GWS
Venting Manual, included in boiler
envelope assembly.
Refer to GWS Venting Manual and to
Boiler Manual Section 1, page 4,
regarding requirements for:
• vent system
• combustion air openings
• combustion air quality
5 Gas piping

13Part Number 550-110-732/0703
GWS Gas-Fired Water Boilers – Boiler Manual
For your safety, turn off electrical power supply at
service entrance panel before making any
electrical connections to avoid possible electric
shock hazard. Failure to do so can cause severe
personal injury or death.
Figure 9 Field wiring connections — service switch and thermostat (or end switch) provided by installer
6 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 per wiring
diagram, Figure 13, on page 18. For other devices, see
manufacturer’s specifications. Also see instructions with
thermostat.
Junction box (furnished)
1. Connect 120 VAC power wiring. See Figure 9.
2. Fused disconnect or service switch (15 amp. recommended)
may be mounted on this box. For those installations with local
codes which prohibit installation of fused disconnect or service
switch on boiler, install a 2 x 4 cover plate on the boiler junction
box and mount the service switch remotely as required by the
code.
Wiring multiple zones
See zone valve manufacturer’s literature for wiring and application.
A separate transformer is required to power zone valves. Zoning
with circulators requires a relay for each circulator.
The GWS control module is polarity-sensitive.The hot and neutral wires must be connected to the correct leads. A flashing
POWER light usually indicates reversed polarity of 120 VAC lead wires.
Wiring must be N.E.C. Class 1.
If 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 18. Circulator is
shipped loose, but wiring harness is pre-attached to the boiler.
Connect wires in circulator junction box.

GWS Gas-Fired Water Boilers – Boiler Manual
14 Part Number 550-110-732/0703
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.
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 39. 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.
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.
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 21 of this manual. Failure
to comply could result in severe personal injury.

15Part Number 550-110-732/0703
GWS Gas-Fired Water Boilers – Boiler Manual
7 Start-up continued
Check burner flame — Pilot burner
Proper pilot flame (see Figure 10):
1. Blue flame.
2. Inner cone engulfing pilot flame sensor.
3. 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.
Check burner flames — Main burner
Proper main burner flame (see Figure 11):
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).
Figure 11 Typical main burner flame
Verify operation
Figure 10 Typical pilot burner flame
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 . . .
• Read manual Sections 8 and 9 and “Operating
instructions”, page 19.
• Verify the boiler and system are full of water.
• Verify the Start-up preparation procedures of this
section have been completed.
Start the boiler
Follow “Operating instructions”, page 19. If boiler fails to start,
see “If boiler doesn’t start . . . Check for:” on this page.
Check system and boiler
Eliminate all system leaks. Continual fresh makeup
water will reduce boiler life. Minerals can build up in
sections, reducing heat transfer, overheating cast iron,
and causing section failure.
If you discover evidence of any gas leak, shut down
the boiler at once. Find the leak source with bubble
test and repair immediately. Do not start boiler again
until corrected. Failure to comply could result in
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.
Venting system must be sealed gas-tight to prevent
flue gas spillage and carbon monoxide emissions.
Failure to comply could result in severe personal injury
or death.
4. Check around the boiler for gas odor following the procedure
of Section 7, page 14 of this manual.
5. Verify operation using procedures below. Perform checkout
procedure in Section 8, page 16, 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,”
page 25 of this manual.

GWS Gas-Fired Water Boilers – Boiler Manual
16 Part Number 550-110-732/0703
Boiler model _______________________________________________________________ Series ____________
CP number _______________________________________ Date installed _________________________________
Measured Btuh input ____________
Installer _______________________ ______________________________ ____________________________
(company) (address) (phone)
_____________________________________
(installer’s signature)
8 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 4,
page 8 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 Operating Instructions on boiler or in manual,
page 19 for proper start-up?
❏Proper burner flame observed? See “Verify operation”,
page 15.
❏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.
❏Test ignition system safety device:
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
wiring diagram label on boiler or in manual, page 18.
❏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.
❏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.
Installation instructions have been followed.
Checkout sequence has been performed.
Above information is certified to be correct.
Information received and left with owner/maintenance person.
Installation and service certificate

17Part Number 550-110-732/0703
GWS Gas-Fired Water Boilers – Boiler Manual
9 Sequence of operation
Figure 12 GWS control module sequence of operation (based on indicator light status)
Follow all procedures given in this manual and
“Operating Instructions”, Section 10, page 19 and on
the inside of the boiler jacket panel, when operating
the boiler. Failure to do so could result in severe
personal injury, death or substantial property damage.
1. Raise room thermostat to call for heat.
2. Inducer and circulator energize. After pressure switch proves
proper airflow, control module initiates 10-second prepurge.
3. Control module sparks the pilot and opens pilot valve in main
gas valve.
a. If pilot does not light within 15 seconds, pilot valve is closed and
spark generator is turned off. Control module initiates a 15-
second postpurge, then starts a new cycle.
b. If pilot does light and control module senses flame current,
spark generator is turned off and main valve opens.
4. During main burner operation:
a. Control module monitors pilot flame current. If signal is lost,
main valve closes, spark generator activates and sequence
returns to step 4.
b. If power is interrupted, control system shuts off pilot and main
gas valves and restarts at step 1 when power is restored.
5. In the event the limit control shuts down the boiler — The
control module closes the gas valve, but keeps the inducer
operating for 15-second postpurge.
— The circulator continues to operate.
6. Lower room thermostat setting to stop call for heat.Thermostat
is satisfied — Pilot and main gas valves are closed — Inducer
operates for 15-second postpurge — Circulator is shut off.
7. Boiler is now in the off cycle.
8. Repeat steps 1 through 6 several times to verify operation.
9. Return the thermostat to normal setting.
10. Set thermostat heat anticipator setting per wiring diagram,
page 18.

GWS Gas-Fired Water Boilers – Boiler Manual
18 Part Number 550-110-732/0703
Figure 13 Wiring diagram — GWS boilers 9 Sequence of operation continued

19Part Number 550-110-732/0703
GWS Gas-Fired Water Boilers – Boiler Manual
10 Operating instructions
Applies to all gas valves used on GWS boilers
FOR YOUR SAFETY READ BEFORE OPERATING
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 is equipped with an ignition
device which automatically lights the pilot. Do
not try to light the pilot by hand.
B. Before OPERATING, 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 depress or move the selector arm. Never use tools.
If the selector arm will not depress or move 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.
WHAT TO DO IF YOU SMELL GAS
1. STOP! Read the safety information above on this label.
2. Set the thermostat to lowest setting.
3. Turn off all electrical power to the appliance.
4. Remove jacket front panel.
5. This appliance is equipped with an ignition device which automatically lights the burner.
Do not try to light the burner by hand.
6. Turn Gas control knob clockwise to OFF.
7. 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.
8. Turn Gas control knob counterclockwise to ON.
9. Turn on all electric power to the appliance.
10. Set thermostat to desired setting.
11. If the appliance will not operate, follow the instructions "TO TURN OFF GAS TO
APPLIANCE" below and call your service technician or gas supplier.
12. Replace jacket front panel.
OPERATING INSTRUCTIONS
TO TURN OFF GAS TO THE APPLIANCE
1. Set the thermostat to lowest setting.
2. Turn off all electric power to the appliance if service is to
be performed.
3. Remove jacket front panel.
4. Turn Gas control knob clockwise to OFF. Do not
force.
5. Replace jacket front panel.

GWS Gas-Fired Water Boilers – Boiler Manual
20 Part Number 550-110-732/0703
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 user)
11 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
• Condensate drain system
❏Service:
• Inducer motor
• 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
❏Cleaning boiler heating surfaces
❏Daily • Check boiler area
• Check boiler pressure/
temperature gauge
• Check air openings
❏Monthly • Check boiler piping
• Check venting system
• Check condensate drain system
• Check boiler relief valve
• Check automatic air vents (if used)
• Check pilot and main burner flames
• Check and clean vent termination & air
intake screens
❏Periodically • Test low water cutoff (if used)
• Oil inducer motor
❏Every 6 months • Operate relief valve
❏End of season • Shut down procedure