Weil-McLain CGi Series 2 User manual

Part Number 550-110-710/0200
2
GOLD CGi Series 2 Gas-Fired Water Boiler
How it works . . .
①Control module
The control module responds to signals from the room thermostat, air pressure switch and
boiler limit circuit to operate the boiler circulator, pilot burner, gas valve and inducer. When
room thermostat calls for heat, the control module starts the system circulator and inducer.
The control module runs the inducer long enough to purge the boiler flue passages, then
opens the pilot valve and activates pilot ignition spark.
The control module allows up to 15 seconds to establish pilot flame. If flame is not sensed
within 15 seconds, the control module will turn off the gas valve, flash the Flame light, and
then enter a 15-second postpurge. The control module will then start a new cycle. This will
continue indefinitely until pilot flame is established or power is interrupted. Once pilot flame
is proven, the control module opens the gas valve to allow main burner flame.
When the room thermostat is satisfied, the control module turns off the gas valve, operates
the inducer for a 15-second postpurge and waits for the next heat call.
The control module indicator lights show normal sequence when the lights are on steady.
When a problem occurs, the control module flashes combinations of lights to indicate the
most likely reason for the problem (see page 47).
②Transformer
The control transformer reduces line voltage to 24 volts for the gas valve and limit circuit.
③Inducer
The inducer pulls flue gases through the boiler, causing air to be pulled in through the boiler
air openings. The inducer pushes the flue gases through the vent pipe as well.
④Air pressure switch
The air pressure switch signals the control module, telling the control module whether the
inducer is working correctly or the vent is blocked.
⑤Water temperature limit switch
The water temperature limit switch turns off the gas valve if the temperature in the boiler
goes above its setting. (The circulator will continue to run as long as there is a call for heat.)
Boiler circulator
The boiler circulator circulates water through the external (system) piping. The circulator is
shipped loose, and can be mounted on either the boiler supply or return piping. The factory-
installed circulator wiring harness provides ample length for either location. NOTE — The
control module provides a pump exercising routine. If the boiler is not operated for 30 days,
the control module will power the circulator for 30 seconds, then turn off.
asupply to system
breturn from system
cstainless steel burners
dflue outlet
egas valve
fpressure/temperature gauge
grelief valve
hair vent connection
iflame rollout thermal fuse
element (TFE)
jburner shield
kpilot burner and bracket
lgas manifold
mcast iron boiler sections
nflue collector
ojunction box
Other boiler components:

Part Number 550-110-710/0200
4
GOLD CGi Series 2 Gas-Fired Water Boiler
Contents
Hazard definitions
The following defined terms are used throughout this manual to bring attention to the presence of hazards of
various risk levels or to important information concerning the life of the product.
Indicates presence of hazards that will cause severe personal injury, death or substantial
property damage.
Indicates presence of hazards that can cause severe personal injury, death or substantial
property damage.
Indicates presence of hazards that will or can cause minor personal injury or property damage.
Indicates special instructions on installation, operation or maintenance that are important
but not related to personal injury or property damage.
How it works .................................................................. 2–3
Hazard definitions.............................................................. 4
Please read before proceeding ......................................... 5
Prepare boiler location ................................................ 6–11
Prepare boiler............................................................. 12–13
Venting ........................................................................ 14-19
Water piping ............................................................... 20-29
Gas piping ........................................................................ 30
Field wiring ...................................................................... 31
Start-up ....................................................................... 32-35
Check-out procedure ....................................................... 36
Operation .................................................................... 37-40
Service and maintenance........................................... 41-45
Troubleshooting ......................................................... 46-55
Replacement parts ..................................................... 56-61
Dimensions and ratings ............................................. 62-63
1
2
3
4
5
6
7
8
9
10
11
12
13

Part Number 550-110-710/0200 5
Boiler Manual
Please read before proceeding
Installer
Read all instructions before
installing. Follow all instructions in
proper order to prevent personal
injury or death.
• Consider piping and installation when
determining boiler location.
• Any claims for damage or shortage in shipment
must be filed immediately against the transporta-
tion company by the consignee.
User
•This manual is for use only by your qualified
heating installer/service technician.
• Please refer to the User’s Information Manual for
your reference.
• We recommend regular service by a qualified
service technician, at least annually.
When calling or writing about the boiler— Please have the boiler model number from the
boiler rating label and the 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 36.
Failure to adhere to the guidelines on this page can result in severe personal injury, death
or substantial property damage.
• 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.
• Do not add cold water to hot boiler. Thermal
shock can cause sections to crack.
When servicing boiler —
• To avoid electric shock, disconnect electrical
supply before performing maintenance.
• To avoid severe burns, allow boiler to cool before
performing maintenance.
Boiler operation —
• Do not block flow of combustion or ventilation
air to boiler.
• 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.
• 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 —
• Do not use petroleum-based cleaning or sealing
compounds in boiler system. Water seal
deterioration will occur, causing leakage between
sections. This can result in substantial property
damage.
• Do not use "homemade cures" or "boiler patent
medicines". Serious damage to boiler, personnel
and/or property may result.
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.

Part Number 550-110-710/0200
6
GOLD CGi Series 2 Gas-Fired Water Boiler
• 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.
The CGi boiler gas manifold and controls met safe
lighting and other performance criteria when boiler
underwent tests specified in ANSI Z21.13–latest
edition.
Prepare boiler location — codes &checklist 1a
Installations must
follow these codes:
Before locating the boiler,
check the following:
• 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.

Part Number 550-110-710/0200 7
Boiler Manual
Prepare boiler location — clearances1b
Figure 1 Recommended clearances for service
Residential garage installation
Precautions
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.
Provide the following clearances:
1. Hot water pipes — at least ½" from combustible
materials.
2. Recommended service clearances — See Figure 1.
3. Minimum clearances for tight spaces — See
Figure 2.
Flooring
The CGi 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
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.
The minimum foundation size is:
Flooring and foundation
Figure 2 Minimum clearances for tight spaces
Boiler
model
Minimum
foundation
length
Minimum
foundation
width
CGi-25 25" 12"
CGi-3 25" 12"
CGi-4 25" 15"
CGi-5 25" 18"
CGi-6 25" 21"
CGi-7 25" 24"
CGi-8 25" 27"
71002
7"
7"
24"
18"
35"
Provide
— 6" from top
and 6" from bottom located
on wall next to boiler front..
(2) fresh air
openings
Each opening must have
free area of square
inch per of
CGi boiler input.
1
1,000 Btuh
71003
6"
2"

Part Number 550-110-710/0200
8
GOLD CGi Series 2 Gas-Fired Water Boiler
Prepare boiler location — vent system
Do not install the CGi 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.
1c
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 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.
Failure to follow all instructions can
result in flue gas spillage and carbon
monoxide emissions, causing
severe personal injury or death.
Chimney or vent requirements
1. Venting must be installed according to Part 7,
Venting of Equipment, of National Fuel Gas Code,
ANSI Z223.1–latest edition and applicable building
codes. Canadian installations must comply with
B149.1 or B149.2 Installation Codes.
2. See Ratings table on page 67 for minimum chimney
or vent sizes. A chimney or vent without a listed
cap should 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.A
chimney or vent must not extend less than the
distances stated above.
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. Weil-McLain
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.
Inspect existing chimney before
installing boiler. Failure to clean or
replace perforated pipe or tile lining
will cause severe personal injury or
death.
CGi venting

Part Number 550-110-710/0200 9
Boiler Manual
Prepare boiler location — contamination
Table 1 Corrosive contaminants
1d
If the boiler is installed in any area likely to cause contamination, or if products which
would contaminate the air cannot be removed, you must either remove products permanently
or isolate the boiler and provide outside combustion air. Contaminated combustion air will
damage the boiler, resulting in possible severe personal injury, death or substantial property
damage.
Air contamination
Please review the following information on potential
combustion air contamination problems.
Refer to Table 1 for products and areas which may cause
contaminated combustion air.
Products to avoid Areas likely to have contaminants
Spray cans containing chloro/fluorocarbons Dry cleaning/laundry areas and establishments
Permanent wave solutions Swimming pools
Chlorinated waxes/cleaners Metal fabrication plants
Chlorine-based swimming pool chemicals Beauty shops
Calcium chloride used for thawing Refrigeration repair shops
Sodium chloride used for water softening Photo processing plants
Refrigerant leaks Auto body shops
Paint or varnish removers Plastic manufacturing plants
Hydrochloric acid/muriatic acid Furniture refinishing areas and establishments
Cements and glues New building construction
Antistatic fabric softeners used in clothes dryers Remodeling areas
Chlorine-type bleaches, detergents, and cleaning
solvents found in household laundry rooms
Garages with workshops
Adhesives used to fasten building products and
other similar products

Part Number 550-110-710/0200
10
GOLD CGi Series 2 Gas-Fired Water Boiler
Prepare boiler location — air openings1e
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.
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.
Air from inside building
(boiler in interior room - Figure 3)
1. Tightly constructed buildings must be provided
with openings to outside for combustion and
ventilation air. These openings must be sized to
handle all fuel burning appliances, exhaust or
ventilation fans and fireplaces.
2. When openings to boiler room are taken to interior
spaces, provide two permanent openings:
• One air opening within 12 inches of floor.
• A second opening within 12 inches of ceiling.
Each opening must provide a minimum free area
of 1 square inch per 1,000 Btuh of input of
all appliances in room plus requirements for any
exhaust fans in room. The interior space supplying
combustion and ventilation air must have adequate
infiltration from outside.
Air directly from outside to boiler
room
1. Tightly constructed buildings must be provided
with combustion and ventilation air openings to
boiler room, which are adequate to handle the
boiler needs plus the needs of all other fuel burning
appliances, exhaust or ventilation fans and
fireplaces.
2. When combustion air is supplied to the boiler
space directly through outside walls (Figure 4):
Provide two permanent openings:
• One air opening within 12 inches of floor.
• A second opening within 12 inches of ceiling.
Each opening must provide a minimum free area
of 1 square inch per 4,000 Btuh of input of all
appliances in room plus requirements for any
exhaust fans in room. The interior space supplying
combustion and ventilation air must have adequate
infiltration from outside.
Figure 3 Air openings to interior space
Figure 4 Air directly from outdoors
3. When combustion air is supplied to the boiler
space directly from outside or ventilated attic/
crawl space through vertical ducts (Figure 5):
Provide two permanent openings:
• One air opening within 12 inches of floor.
• A second opening within 12 inches of ceiling.
Each opening must provide a minimum free area
of 1 square inch per 4,000 Btuh of input of all
appliances in room plus requirements for any
exhaust fans in room. The duct cross sectional area
must be no less than the required area of the
permanent openings.
Air
opening
Add air openings
to outside if
building is tight
construction.
Air
opening
0 to 12"
0 to 12"
Other
appliances
Each opening free area =
1 sq. inch per 1,000 Btuh
71004
CGi
boiler
MODEL
CGi
Other
appliances
Air
opening
Air
opening
0 to 12"
0 to 12"
Outside
Each opening free area =
1 sq. inch per 4,000 Btuh
71005
CGi
boiler
MODEL
CGi

Part Number 550-110-710/0200 11
Boiler Manual
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 4 if appliances are to use
inside air for combustion and ventilation.
4. When combustion air is supplied to the boiler
space directly from outside through horizontal
ducts (Figure 6): Provide two permanent openings:
• One air opening within 12 inches of floor.
• A second opening within 12 inches of ceiling.
Each opening must provide a minimum free area
of 1 square inch per 2,000 Btuh of input of all
appliances in room plus requirements for any
exhaust fans in room. The duct cross sectional area
must be no less than the required area of the
permanent openings.
Exhaust fans and air movers
The appliance space must never be under a negative
pressure, even if the appliance(s) 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.
Figure 6 Air from outdoors — horizontal
ducts
Figure 5 Air from outdoors — vertical ducts
Air
opening
Air
opening
0 to 12"
0 to 12"
Other
appliances
CGi
boiler
O
ut
s
i
de
Each opening free area =
1 sq. inch per 2,000 Btuh
71007
MODEL
CGi
12"
Other
appliances
Outside or ventilated attic
Ventilated
crawl space
— or —
Each opening free area =
1 sq. inch per 4,000 Btuh
71006
CGi
boiler
MODEL
CGi

Part Number 550-110-710/0200
12
GOLD CGi Series 2 Gas-Fired Water Boiler
Prepare boiler — placement & setup2a
Table 2 Manifold orifice sizing at sea level and altitudes to 4,500 feet
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.
4. Remove boiler from pallet.
Do not drop boiler or bump jacket
on floor or pallet. Damage to boiler
can result.
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 backward off pallet and into
position.
5. Check level.
a. Shim legs, if necessary.
b. Do not alter legs.
Inspect orifices and burners
1. Remove front jacket door. Remove burner shield
(see Figure 40, item 4, page 58).
2. Check for correctly-sized manifold orifices. See
Table 2 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,
Orifice replacement procedure
(when required)
1. Remove the screws securing the burner shield and
remove burner shield.
2. Using a 7 /16" open-end wrench, remove the burner
orifices from the manifold.
3. Apply a small amount of pipe dope to each of the
new orifices and install in the manifold using a 7
/16"
open-end wrench. Make sure the orifices are aligned
correctly, not cross-threaded in the manifold
tappings.
Use only pipe dope compatible with
propane gas, even if boiler is to be
operated on natural gas. Failure to
comply could result in severe
personal injury, death or substantial
property damage.
4. Carefully replace the burner shield.
5. Follow the check-out procedure, section 8page 36,
to assure the boiler is now operating properly after
orifices are replaced.
Location Boiler model
number
Natural gas Propane gas
0-2,000 ft over 2,000 ft 0-2,000 ft over 2,000 ft
U. S. CGi-25 2.30 mm (Note 1) #54 (Note 1)
CGi-3 — CGi-8 2.70 mm 1.65 mm
Canada
0-2,000 ft 2,000-4,500 0-2,000 ft 2,000-4,500
CGi-25 2.30 mm #44 #54 #55
CGi-3 — CGi-8 2.70 mm #38 1.65 mm #53
Note 1: For elevations above 2,000 feet, contact your local Weil-McLain sales office for details.
death or substantial property
damage.
3. Reinstall burner shield.
Do not operate boiler without
burner shield in place. Failure to do
so could result in severe personal
injury, death or substantial property
damage.

Part Number 550-110-710/0200 13
Boiler Manual
Prepare boiler — pressure test
Pressure test boiler before attaching water or gas piping (except as noted below) or electrical
supply.
Prepare boiler for test
1. Remove the shipping nipple (from CGi 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 circulator hardware and pressure/
temperature gauge carton. Install in boiler return connection as shown on page 3 and
Figure 42, page 60. Install circulator on either the return or supply.
3. Remove 1¼" nipple, 1¼" x 1¼" x ½" tee and pressure/temperature gauge from circulator
hardware and pressure/temperature gauge carton. Pipe to boiler supply connection as
shown on page 3 and Figure 42, page 60. (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.
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 on the pressure/temperature gauge
reaches no more than:
•45 psig for boilers with 30 psig relief valve.
•75 psig for boilers with 50 psig relief valve.
6. Test for no more than 10 minutes at:
•45 psig for boilers with 30 psig relief valve.
•75 psig for boilers with 50 psig relief valve.
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 4a, page 20 to replace relief valve.
2b
Perform hydrostatic pressure test

Part Number 550-110-710/0200
14
GOLD CGi Series 2 Gas-Fired Water Boiler
Venting — general information 3a
CGi venting methods
The CGi boiler can be vented using one of the following
methods:
1. Chimney draft venting — Uses the natural draft
provided by a vertical vent or chimney. Category I
appliance (non-positive vent static pressure and
vent gas temperature that avoids excessive
condensate production in vent). See section 3b,
below. Chimney draft installations use:
a. Vent connector (single or doublewall) sized to
eliminate positive pressure in vent system.
Diameter increases immediately at boiler.
b. Doublewall metal vent (B-vent) or chimney
with liner approved by the National Fuel Gas
Code, ANSI Z223.1–latest edition, or in Canada
B149.1 or B149.2 Installation Code.
2. Direct exhaust — vertical or sidewall — Uses
inside combustion air with no combustion air
connector piping. All CGi flue gas vents are
pressurized, requiring careful sealing of all joints.
Category III appliance (positive vent static pressure
and vent gas temperature that avoids excessive
condensate production in vent). See pages 15-19.
Direct exhaust installations use:
a. Vent pipe specified in this manual.
b. Vent termination through outside wall, roof or
unused chimney. Tight chimney areas will make
vent joint construction very difficult.
Venting — chimney draft venting 3b
1. Use doublewall metal vent (B-vent) or chimney with liner
as required by the National Fuel Gas Code, ANSI Z223.1–
latest edition, or in Canada, B149.1 or B149.2 Installation
Code.
2. To prevent downdrafts, chimney should extend at least 3
feet above the highest point where it passes through a roof
and at least 2 feet higher than any portion of a building
within a horizontal distance of 10 feet.
3. To vent with another appliance,see National Fuel Gas Code,
ANSI Z223.1–latest edition or in Canada B149.2 or B149.2
Installation Code
4. Do not connect breeching to any portion of a mechanical
draft system that can operate under positive pressure.
5. Maintain minimum 2" clearance from combustible
materials to vent pipe.
6. Do not use chimney with an open fireplace.
7. Make horizontal runs as short as possible. Long runs can
cause condensation.
8. When longer runs are used, support pipe with appropriate
hangers.
9. To prevent blockage, do not vent into bottom of chimney.
10. Vent pipe must not go beyond inside wall of chimney.
11. Vent passing through floors or ceilings must be firestopped.
12. See Figure 7 and Table 3 to connect boiler to venting system.
Inspect existing chimney before installing boiler.
Failure to clean or replace perforate pipe or lining will
cause severe personal injury or death.
Table 3
Vent
connector
diameter Vent sizing given in Table 3 is only a general guideline.
The vent connector and chimney must be designed,
sized and constructed in compliance with all applicable
codes. Failure to correctly size and install the vent
system could result in severe personal injury, death or
substantial property damage.
Boiler
model
number
“D” Minimum
vent connector
diameter
CGi-25 & CGi-3 4"
CGi-4 to CGi-8 5"
Figure 7
Chimney
draft venting
MODEL
CGi
71008
Chimney
Cleanout
Tight
seal
1/4" Rise/4 FT.
D
D
0322-057
Increaser

Part Number 550-110-710/0200 15
Boiler Manual
Venting —
direct exhaust — system components
3c
1. The following special gas vent systems comply with
UL-1738 and ULC-S636 standards and are certified
by CSA as the only systems suitable for use with
CGi boilers (all 3" diameter):
• Heat-Fab, Inc. Saf-T Vent®
• Flex-L International, Inc. StaR-34
• Z-Flex®, Inc. Z-Vent II
• ProTech Systems FasNSeal™
Use only the vent starter of the same
manufacturer as the vent compo-
nents. Do not mix components
from different systems. The vent
system could fail, causing flue gas
spillage, resulting in severe personal
injury or death.
2. Select vent method based on page 14 and
installation requirements.
Table 4 Maximum vent length
3. Refer to Table 4 for maximum vent run lengths and
number of elbows. Do not exceed data in Table 4.
4. Select vent components from Table 5. All
components, including the vent starter, must be of
the same vent manufacturer. Do not mix
components.
Table 5 Vent system components
Description Saf-T Vent
®
StaR-34 Z-Vent II FasNSeal™
Weil-McLain
part number
Saf-T Vent
®
part number
CGi Starter 699-999-015 73WMCGIS SRAWCG3 SVEWMFA03 FSA-WEIL-CGI
Termination Coupling with
Screen
699-999-001 73WMTERM -- SVSTPX03 FSB3S
Termination Elbow with Screen 699-999-069 1314TERM SRTE-03 SVSTEX0390 FSTE90
Termination Tee with Screen 699-999-026 7390TEE SRTT-03 SVSTTX03 FSTT3
45˚ Elbow 699-999-010 7311GC SRE4503 SVEEWC0345 FSEL4503
90˚ Elbow 699-999-011 7314GCTR SRE9003 SVEEWC0390 FSEL9003
6" Pipe 699-999-003 7301GC SR06P03 SVEPWC03.5 FSVL603
12" Pipe 699-999-004 7302GC SR12P03 SVEPWC0301 FSVL1203
18" Pipe 699-999-005 7304GC -- SVEPWC0318 FSVL1803
24" Pipe 699-999-006 7305GC SR24P03 SVEPWC03 FSVL2403
36" Pipe -- -- SR36P03 SVEPWC0303 FSVL3603
37 ½" Pipe 699-999-007 7307GC -- -- --
48" Pipe -- -- -- SVEPWC0304 --
49 ½" Pipe 699-999-008 7308GC -- -- --
60" Pipe 699-999-012 7360GC SR60P03 SVEPWC0305 --
Slip Connector (See Note) 699-999-009 7324GC9 SRSJ03 -- --
Horizontal Support 699-999-016 7323GC -- -- FSSH
Horizontal Drain Tee 699-999-014 7320GC SRTDH03 SVEDWC03 FSHDT3
Joiner Band -- -- SRJB-14 -- --
Sealant As specified by individual vent pipe manufacturer Not required
Note: Use to adjust for non-standard pipe lengths and Saf-T Vent
®
only, before termination coupling to terminate run.
Obtain vent system components
Max.vent
length (feet)
Total number of elbows
(Note 1)
1 2 3 4 5 6
CGi-25 to CGi-6 55 48 41 34 27 20
CGi-7 35 28 21 14 7 --
CGi-8 28 21 14 7 -- --
Note 1: Do not include termination fitting when
counting total number of elbows.

Part Number 550-110-710/0200
16
GOLD CGi Series 2 Gas-Fired Water Boiler
Venting — direct exhaust — vent starter 3d
Figure 8
FasNSeal™vent starter
Figure 9
Z-Vent II vent starter
Figure 11
StaR-34 vent starter
Figure 10
Saf-T Vent®vent
starter
1. Select a vent pipe manufacturer and obtain all vent
components needed, based on boiler location and
venting method.
2. You must use the vent starter made by the vent pipe
manufacturer. See Table 5, page 15, Vent system
components, for part number of each component,
listed by vent manufacturer.
Use only the vent starter of the same
manufacturer as the vent compo-
nents. Do not mix components
from different systems. The vent
system could fail, causing flue gas
spillage, resulting in severe personal
injury or death.
3. Follow all applicable national, state, local or
provincial codes when venting the CGi boiler.
4. Connect vent starter to blower housing outlet as
shown in the Figures 8 through 11, below.
a. Do not mix components from different vent
manufacturers.
b. Maintain minimum 2" clearance from
combustible materials to vent pipe.
c. Seal with sealant specified by vent pipe
manufacturer, using ³⁄₈" bead (not required for
FasNSeal™).
d. Tighten strap at band clamp screw until strap
is snug around blower housing.
71010
Z-Vent II
starter
Feed
position
Tighten
position
Band clamp
screw
Band clamp
strap
Blower
housing
outlet
³⁄₈" Bead
of sealant
71011
Saf-T Vent ®
starter
Band clamp
screw
Band clamp
strap
Blower
housing
outlet
³⁄₈" Bead of
sealant
71012
Band clamp
screw
Band clamp
strap
Blower
housing
outlet
3/8" Bead
of sealant
StaR-34
starter
71009
FasNSeal™
starter
Band clamp
screw
Band clamp
screw
Band clamp
strap
Blower
housing
outlet

Part Number 550-110-710/0200 17
Boiler Manual
1. Locate the boiler and vent penetration through the
wall so all requirements on this page and in Figure
12 will be met. Also follow vent manufacturer’s
instructions.
2. Gases will form white plume in winter. Plume could
obstruct window view.
3. Prevailing winds could cause freezing of
condensate and water/ice buildup on vent
termination, building, plants or roof. Ice buildup
on vent termination can cause boiler shutdown and
building freezeup.
4. Winds over 31 mph can cause nuisance boiler
shutdown if boiler is sidewall vented. This could
result in loss of heat to building, causing freezeup.
5. Locate or guard vent termination to prevent
condensate from damaging exterior surfaces.
6. Locate the vent termination well away from trees,
shrubs, and decorative items.
7. Locate or guard vent to prevent accidental contact
by people or pets.
8. Do not terminate vent in window well, stairwell,
alcove, courtyard, or other recessed areas.
9. Do not wrap or insulate vent pipe or fittings.
10. Do not terminate vent above any door or window.
Condensate can freeze, causing ice formations.
11. Do not connect:
• Any other appliance to vent pipe.
• Multiple boilers to a common vent pipe.
Figure 12 Vent termination minimum clearances
12. Canadian installations — See B149.1 or B149.2
Installation Code. Terminate vent no less than 6 feet
from another combustion air inlet, 3 feet from any
other building opening, and 3 feet from any gas
service regulator.
13. See Figure 12, showing that the vent must terminate:
• more than 4 feet below or to side of all doors
or windows.
• more than 1 foot above grade or anticipated
snow line.
• at least 7 feet above public walkway.
• 3 feet above any forced air intake within 10 feet.
14. Vent must also terminate:
• at least 6 feet away from adjacent walls.
• no closer than 5 feet below roof overhang.
• at least 4 feet horizontally (and in no case above
or below unless a 4 foot horizontal distance is
maintained) from electric meters, gas meters,
regulators, relief valves, and other equipment.
15. Site conditions may dictate greater clearances.
16. Do not extend exposed vent pipe outside of
building. Condensate could freeze and block vent
pipe.
A gas vent extending through an
exterior wall shall not terminate
adjacent to the wall or below
building extensions such as eaves,
parapets, balconies or decks. Failure
to comply could result in severe
personal injury, death or substantial
property damage.
Follow instructions on this page when determining
vent location to avoid possibility of severe personal
injury, death or substantial property damage.
Venting —
direct exhaust — vent termination
3e
71013
Forced
air intake
Public Walkway
3 feet
If within 10 feet
7 feet
71014
Snow
4 ft
4 ft
1 ft
4 feet

Part Number 550-110-710/0200
18
GOLD CGi Series 2 Gas-Fired Water Boiler
Venting — direct exhaust............................ 3f
1. Do not mix types or manufacturers of vent materials.
2. Clean all joints before sealing. See vent manufacturer’s instructions for
cleaning and sealing joints. Use their specified sealant. Do not use screws.
3. Install vent pipe with seams on top of vent horizontal runs. Follow
requirements in section 3e, page 17, for vent termination.
4. Maintain minimum 2" clearance from combustible materials to vent
pipe.
5. Vertical venting — See Figure13. Follow vent manufacturer’s
instructions for venting through roof.
• Vent pipe must extend through roof flashing, jacket or thimble.
• Vent may pass through floor, inside wall or concealed space when
installed according to vent manufacturer’s instructions.
Sidewall venting — See Figures 14 and 15. Vent must terminate at
least one foot above anticipated snowline. Vent must be terminated
only with:
• Tee or elbow with integral screen. (Tee may be mounted either
vertically or horizontally. DO NOT use horizontal tee with CGi-7
or CGi-8.)
• Elbow and termination coupling with screen (not available for
StaR-34).
6. Do not seal vent pipe (slip connector for Saf-T Vent) to inside or outside
plate.
7. If passing through noncombustible wall, provide hole diameter large
enough to insert the vent pipe (slip connector for Saf-T Vent).
8. Install horizontal drain tee as close as possible to boiler, in first
horizontal run. See Figure 13.
9. Do not exceed the maximum vent system length given in Table 4,
page 15.
Condensate drain line — use only silicone tubing
rated for at least 400 °F for the condensate drain line.
Using any other material could cause flue gas leakage, potentially
resulting in severe personal injury, death or substantial property
damage.
On some installations, the condensate drain fitting
may be omitted, provided:
• Vent manufacturer shows this option in their instructions.
• Vent is sloped toward termination as shown in dotted lines in Figure
14.
• The vent is installed per Weil-McLain and vent manufacturer’s
instructions.
Condensate drippage from such vents may accumulate on the ground
below. Consider traffic in the area to avoid hazard due to ice accumulation.
Figure 13 Direct exhaust vertical venting
Figure 14 Direct exhaust sidewall venting
MODEL
CGi
71015
Horizontal drain tee.
Follow vent
manufacturer's
instructions to install
condensate drain line.
Follow vent
manufacturer's
instructions for proper
installation of vent runs,
including slope and
support.
MODEL
CGi
71016
Horizontal drain tee.
Follow vent
manufacturer's
instructions to install
condensate drain line.
Optional downward
slope without drain
fitting, where allowed
by vent manufacturer
as explained in
CAUTION at left.
Follow vent
manufacturer's instructions for
proper installation of vent runs,
including slope, support and
condensate drainage.

Part Number 550-110-710/0200 19
Boiler Manual
Figure 15 Sidewall termination
vertical or sidewall
Using any termination other than one of those shown
could cause nuisance outages and loss of heat, resulting
in substantial property damage.
Pipe
section
Metal
plate
Metal
plate
Band
clamp
18" Slip
connector
Exterior
wall
Sealant
Sealant
Sealant
Sealant
Saf-T Vent®
Sealant
Sealant
Pipe
section
Metal
plate
Metal
plate
Exterior
wall
Pipe
section
Sealant
StaR-34
Elbow and termination
coupling with screen
Elbow and termination
coupling with screen
Termination coupling
not available
Elbow and termination
coupling with screen
Termination elbow or tee
Termination elbow or tee
Termination elbow or tee
Termination elbow or tee
Sealant
Z-Vent II
Metal
plate
Metal
plate
Exterior
wall
Pipe section
Pipe
section
Locking
band
FasNSeal™
71017
Metal
plate
Metal
plate
Exterior
wall
Pipe section
Sealant
Pipe
section
Sealant
Note 1 Note 1: DO NOT use horizontal tee with CGi-7 or CGi-8.
Note 1: DO NOT use horizontal tee with CGi-7 or CGi-8.
Note 1: DO NOT use horizontal tee with CGi-7 or CGi-8.
Note 1: DO NOT use horizontal tee with CGi-7 or CGi-8.
Note 1
Note 1
Note 1

Part Number 550-110-710/0200
20
GOLD CGi Series 2 Gas-Fired Water Boiler
Water piping — general information 4a
General piping information
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 section 9b, pages 38 and 39, for wiring.
Alow 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 as required by local codes.
Relief valve
Install relief valve vertically in ¾" tapping on side of boiler. See Figure 16
or 17 and the tag attached to the relief valve for manufacturer’s instructions.
Table 6 Water pipe size (based on 20 °F rise)
Boiler
model number
To
system
From
system
CGi-25 ¾" ¾"
CGi-3 1" 1"
CGi-4 1" 1"
CGi-5 1" 1"
CGi-6 1¼" 1¼"
CGi-7 1¼" 1¼"
CGi-8 1½" 1½"
Note: Circulator flange supplied with boiler is same size as
recommended piping above.
To avoid water damage or scalding due to relief 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.
System water piping
See Figure 16 (diaphragm-type or bladder-type
expansion tank) or Figure 17 (closed-type expansion
tank) on page 21, and Table 6 below, for near-boiler
and single-zone systems designed for return water at
least 130 °F.
See pages 22-23 to complete multiple-zone piping or
pages 24-29 to complete piping for radiant heating
systems or converted gravity systems.
Refer to page 29 for boilers used with refrigeration systems.
Install boiler such that —
• Chilled medium, if used, 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.
Pressure/temperature gauge
Install pressure/temperature gauge in tee on supply piping (as shown in
drawing on page 3). The gauge well is a self-closing valve, allowing removal
of the gauge without draining the system.
Slowly remove pressure/temperature gauge from well.
The self-closing valve could leak if clogged with
sediment. If water begins to spray, stop removing gauge.
Close system fill valve and drain enough water to release
system pressure before continuing with gauge removal.
Escaping hot water could cause severe personal injury.
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 3 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 16 and 17 show
typical near-boiler piping connections.