Weil-McLain CGS 550-110-260-02002 User Manual
GOLD CGs Gas-Fired Water Boiler
How it works . . .
①
②
③
Control 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 43).
Transformer
The control transformer reduces line voltage to 24 volts for the gas valve and limit circuit.
Inducer
The inducer pulls flue gases through the boiler, causing air to be pulled in through the air
intake opening. The inducer pushes the flue gases through the vent pipe as well.
④
⑤
Air pressure switch
The air pressure switch signals the control module, telling the control module whether air is
moving through the inducer.
Water 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 factoryinstalled 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.
Other boiler components:
a supply to system
b return from system
c combustion air inlet
d flue outlet
e gas valve
f pressure/temperature gauge
g relief valve (not visible)
h air vent connection
i flame rollout switch
j air inlet box
k pilot burner and bracket
l stainless steel burners
m cast iron boiler sections
n flue collector
o junction box
2
Part number 550-110-260/0200
GOLD CGs Gas-Fired Water Boiler
Contents
How it works .................................................................. 2–3
Hazard definitions.............................................................. 4
Please read before proceeding ......................................... 5
1. Prepare boiler location ............................................ 6–11
2. Prepare boiler......................................................... 12–13
3. Water piping........................................................... 14–23
4. Venting & combustion air............................................ 24
5. Gas piping .............................................................. 24–25
6. Field wiring................................................................... 26
7. Start-up .................................................................. 27–29
8. Check-out procedure ................................................... 30
9. Operation ............................................................... 31–34
10. Service and maintenance.................................... 35–40
11. Troubleshooting .................................................. 41–51
12. Replacement parts............................................... 52–57
13. Dimensions and ratings ...................................... 58–59
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.
4
Part number 550-110-260/0200
Boiler Manual
Please read before proceeding
Installer
Read all instructions before
installing.
proper order to prevent personal
injury or death.
• Also refer to CGs Venting Supplements.
• 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.
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 30.
Failure to adhere to the guidelines on this page can result in severe personal injury, death
or substantial property damage.
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.
Follow all instructions in
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
• 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.
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 550-110-260/0200
5
GOLD CGs Gas-Fired Water Boiler
1a
Prepare boiler location —
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.
The CGs boiler gas manifold and controls met safe
lighting and other performance criteria when boiler
underwent tests specified in ANSI Z21.13 — latest
edition.
codes & checklist
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.
6
Part number 550-110-260/0200
Boiler Manual
Prepare boiler location — clearances1b
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.
Figure 1 Recommended clearances for service
Figure 2 Minimum clearances for tight spaces
Flooring and foundation
Flooring
The CGs 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
Boiler model number Width — Inches
CGs-3 15
CGs-4 18
CGs-5 21
CGs-6 24
25" long by:
Part number 550-110-260/0200
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
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.
of the garage to assure the
7
GOLD CGs Gas-Fired Water Boiler
1c
Prepare boiler location — vent system
Removing from existing vent
Do not install the CGs 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.
Failure to follow all instructions can
result in flue gas spillage and carbon
monoxide emissions, causing
severe personal injury or death.
When removing boiler from existing
common vent system:
At the time of removal of an existing boiler, the
following steps shall be followed with each appliance
remaining connected to the common venting system
placed in operation, while the other appliances
remaining connected to the common venting system
are not in operation.
a. Seal any unused openings in the common venting
system.
Visually inspect the venting system for proper
b.
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 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, or smoke from a cigarette,
cigar, or pipe.
f. After it has been determined that
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
each appliance
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.
CGs special vent system
Vent system
The CGs boiler requires a special vent system, designed
for pressurized venting. Model CGs-3 is rated ANSI
Z21.13 Category IV (pressurized vent, likely to
condense in the vent). Models CGs-4, -5 and -6 are rated
Z21.13 Category III (pressurized vent).
You may use any of the vent systems covered by the
CGs Venting Supplements included in the envelope
assembly. The CGs vent starter is a special item, designed
only for the CGs boiler, available from each vendor.
Do not attempt to connect the vent to the CGs 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
The CGs boiler may be vented through the roof or
through a side wall. Follow the appropriate vent
supplement for the vent system chosen. The maximum
vent length depends on boiler size. Refer to the vent
supplement to determine acceptable vent length.
Combustion air for the CGs boiler 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 Weil-
McLain Through-Roof or Through-Unused
Chimney
Vertical Direct Venting Venting Supplement, 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
Refer to
Exhaust Venting: Vertical or Sidewall
Supplement shipped with the boiler.
termination kit and supplement. Refer to
termination kit shipped with the boiler.
CGs Direct Venting: Sidewall & Direct
Venting
8
Part number 550-110-260/0200
Boiler Manual
1d
Prepare boiler location — contamination
Air contamination
Please review the following information on potential
combustion air contamination problems.
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 pipe combustion air to the boiler
air intake. Contaminated combustion air will damage the boiler, resulting in possible severe
personal injury, death or substantial property damage. Do not install CGs boiler in a
room or pool facility, for example, without using ducted outside air. These areas will always
contain contaminants.
Table 1 Corrosive contaminants
Products to avoid Areas likely to have contaminants
Spray cans containing chloro/fluorocarbons Dry cleaning/laundry areas and establishments
Permanent wave solutions Swimming pools
Refer to Table 1 for products and areas which may cause
contaminated combustion air.
laundry
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 550-110-260/0200
9
GOLD CGs Gas-Fired Water Boiler
Prepare boiler location — air openings1e
CGs combustion air options
Using inside air — direct exhaust vent
The CGs boiler can use inside air if no contaminants
are present in the boiler space. If contaminants are likely
to be present, install the CGs boiler as a direct vent
appliance, using the appropriate vent supplement and
the instructions in this manual.
Using outside air — direct vent
Combustion air can be ducted directly from outside
to the CGs boiler air intake fitting. This method is
defined as
combustion). Refer to the appropriate vent supplement
and the instructions in this manual. Two options are
available: sidewall or vertical direct vent. Each requires
a special vent component kit.
direct vent (also referred to as sealed
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.
Figure 3, selecting the appropriate installation
Use
conditions. Note that the sizing given in Figure 3
applies only to CGs installations with clearances no
smaller than shown in Figure 1, page 7 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.
Louver allowance
The free area of openings means the area after
reduction for any installed louvers or grilles
to consider this reduction when sizing the air openings.
. Be sure
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
inside air for combustion and ventilation.
Exhaust fans and air movers
The appliance space must never be under a negative
pressure unless all 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
Figure 3 if appliances are to use
10
The sizing given in Figure 3 is based on the National
Fuel Gas Code, ANSI Z223.1, allowing adequate air
opening for gravity-vented gas appliances (Category I).
The CGs boiler is rated Category III or IV (pressurized
vent), and has different requirements for combustion
and ventilation air, reflected by the special sizing
instructions given in Figure 3. The air openings
recommended in Figure 3 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.
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
(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.
Part number 550-110-260/0200
isolated contact
Boiler Manual
Figure 3 Sizing air openings for CGs installations
Room Air Openings
Required area of the air openings given in this
table are free area — after the correction for
louver obstruction. (See below.)Exception
Apply this table only to installations with
clearances no smaller than those shown in
Figure 1, page 7 of this manual.
For installations with clearances less than
shown in Figure 1, page 7 of this manual,
provide 2 openings, each with 1 square inch
of free area per 1,000 Btuh of total input of
all appliances.
A
Air from Inside
CGs
B
Air
Directly
from
CGs
Outside
12”
Max
12”
Max
Air
opening
Air
opening
12”
Max
opening
opening
12”
Max
Inside
Air
Air
Direct exhaust vent installation
(CGs using room air for combustion)
Other
appliances
CGs CGs
Room
with other appliances
2 Openings —
each opening:
1 square inch
free area per
Outside
1,000
Btuh input of
other appliances
shared Room
CGs
2 Openings —
each opening:
1 square inch
free area per
4,000
of
plus CGs
2 Openings —
each opening:
1 square inch
free area per
Outside
4,000
Btuh input of
other appliances
2 Openings —
each opening:
1 square inch
free area per
4,000
of
plus CGs
Direct vent installation
(combustion air piped to CGs)
Combustion
Other
appliances
alone CGs
in room
with other appliances
air piping
CGs
shared
2 Openings —
each opening:
1 square inch
free area per
1,000
Btuh input
CGs
Btuh input of
other appliances
only (not )
CGs
2 Openings —
each opening:
1 square inch
free area per
4,000
Btuh input
CGs
Btuh input of
other appliances
only (not )
CGs
Combustion
air piping
CGs
alone
in room
NO Openings are
needed, provided:
Clearance around
boiler is
NO LESS
than shown in
Figure 1, page 7
of this manual.
NO Openings are
needed, provided:
Clearance around
boiler is
NO LESS
than shown in
Figure 1, page 7
of this manual.
C
Air from
Outside
Through horizontal
ducts
CGs
Outside or ventilated attic
D
Air from or —
Outside Attic
Lower Opening in Floor
or Vertical Duct
CGs
Ventilated
crawl space
26007
Exception to
combustion air
opening rules:
NO Openings are
needed, provided:
Clearance around
boiler is
NO LESS
than shown in
Figure 1, page 7
of this manual.
NO Openings are
needed, provided:
Clearance around
boiler is
NO LESS
than shown in
Figure 1, page 7
of this manual.
Max
Max
12”
12”
Max
Air
opening
Air
opening
12”
Duct
2 Openings —
each opening:
Duct
1 square inch
Inside
Duct
free area per
Outside
2,000
other appliances
plus CGs
Btuh input of
2 Openings —
each opening:
1 square inch
free area per
Outside
4,000
Or
Btuh input of
other appliances
2 Openings —
each opening:
1 square inch
free area per
4,000
Btuh input
CGs
of
2 Openings —
each opening:
1 square inch
free area per
4,000
Btuh input
CGs
of
plus CGs
combustion air openings are needed when theboiler (and other appliances) are installed ina space with a volume
NO
NO LESS
(1,000's of Btuh) andmultiply this numbertimes 50. (see page 10).
Example:
than 50 cubic feet per 1,000 Btuh of all installed appliances. Sum the total input of all appliances in MBH
Building must not be of Tight construction
For total input of 100 MBH (100,000 Btuh), minimum volume is 50 x 100 = 5,000 cubic feet. At a ceiling
2 Openings —
each opening:
1 square inch
free area per
2,000
Btuh input of
other appliances
only (not )
CGs
2 Openings —
each opening:
1 square inch
free area per
4,000
Btuh input of
other appliances
only (not )
CGs
height of 8feet, space must have at least 5,000÷8=625square feet (25feet x 25 feet, for instance).
Part number 550-110-260/0200
11
GOLD CGs Gas-Fired Water Boiler
Prepare boiler — placement & setup2a
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 inlet air box
top panel (see Figure 27, item 13, page 54).
death or substantial property
damage.
3. Reinstall inlet air box top panel.
Inlet air box top panel must be in
position during boiler operation.
Failure to do so could result in
severe personal injury, death or
substantial property damage.
Orifice replacement procedure
(when required)
1. Remove the screws securing the inlet air box top
panel.
2. Remove inlet air box top panel and inspect the fiber
gasket. Verify the gasket is in good condition and
can seal around the complete perimeter of the air
box. Replace the gasket if necessary.
3. Using a 7/16" open-end wrench, remove the burner
orifices from the manifold.
4. 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.
12
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,
Table 2 Manifold orifice sizing
Location Natural gas Propane gas
0-2,000 ft over 2,000 ft 0-2,000 ft over 2,000 ft
U. S.
2.70 mm (Note 1) 1.65 mm (Note 1)
0-2,000 ft 2,000-4,500 0-2,000 ft 2,000-4,500
Canada
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.
5. Carefully replace the inlet air box top panel, making
sure the gasket is in place will seal all around the
perimeter.
6. Follow the check-out procedure, section
to assure the boiler is now operating properly after
orifices are replaced.
8 page 30,
Part number 550-110-260/0200
Boiler Manual
2b
Prepare boiler — pressure test
Perform hydrostatic 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 CGs 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 page 3 and
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 on page 3 and Figure 29, page 56. (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
6. Test for no more than 10 minutes at:
• 45 psig
• 75 psig
7. Make sure constant gauge pressure has been maintained throughout test. Check for leaks.
Repair if found.
for boilers with 50 psig relief valve.
for boilers with 30 psig relief valve.
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.
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.
Figure 29, page 56. Install circulator on either
Part number 550-110-260/0200
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 3a to replace relief valve.
13
GOLD CGs Gas-Fired Water Boiler
Boiler
model
number
To
system
From
system
CGs-3 1" 1"
CGs-4 1" 1"
CGs-5 1" 1"
CGs-6 1 ¼" 1 ¼"
Note: Circulator flange supplied with boiler is same size as
recommended piping above.
3a
Water piping —
general information
General piping information
If installation is to comply with ASME or Canadian requirements, an
additional
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
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 probetype 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.
high temperature limit is needed. Install control in supply
9b, page 32 for wiring.
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 4 and 5 show typical
near-boiler piping connections.
System water piping
See Figure 4 (diaphragm-type or bladder-type
expansion tank) or
tank) on page 15, and
and single-zone systems designed for return water at
least 130 °F.
See pages 16-17 to complete multiple-zone piping or
pages 18-23 to complete piping for radiant heating
systems or converted gravity systems.
Refer to page 23 for boilers used with refrigeration systems.
Figure 5 (closed-type expansion
Table 3 below, for near-boiler
Relief valve
Install relief valve vertically in ¾" tapping on side of boiler. See Figure 4
and the tag attached to the relief valve for manufacturer’s instructions.
or 5
To avoid water damage or scalding due to relief valve
operation:
• Discharge line must be connected to relief valve outlet and
safe place of disposal
possibility of severe burns should the valve discharge.
• Discharge line must be as short as possible and be the
the valve discharge connection
• Discharge line must
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.
14
. Terminate the discharge line to eliminate
throughout its entire length.
pitch downward from the valve and terminate at
Table 3 Water pipe size (based on 20 °F rise)
run to a
same size as
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.
Part number 550-110-260/0200
Boiler Manual
Water piping — single-zone system3b
Expansion tank
Diaphragm-type or bladder-type
expansion tank — Figure 4
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
shown.
automatic air vent in air vent tapping as
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.
Use Figure 4 or Figure 5 only for single-zone 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, refer to the special piping suggestions of pages 18-23. 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.
Closed-type expansion tank —
Figure 5
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.
Figure 4 Diaphragm- or bladder-type expansion tank
Piping to single-zone system using
diaphragm-type or bladder-type expansion
tank. See Table 3 for piping sizes.
From
system
Isolation
valve
Relief
valve
Cold
water
fill
To DIAPHRAGM
expansion tank
and fittings
Isolation
valve
To system
Circulator*
Automatic
air vent
Figure 5 Closed-type expansion tank
Piping to single-zone system using closedtype expansion tank. See Table 3 for piping
sizes.
CLOSED-type
expansion tank
From
system
Isolation
valve
Relief
valve
Cold water fill
Isolation
valve
To system
Circulator*
Circulator
26010
Part number 550-110-260/0200
Drain
valve
*Alternate
location
Circulator
26011
Drain
valve
*Alternate
location
15
GOLD CGs Gas-Fired Water Boiler
Water piping — multiple zones3c
Piping multiple zones
Zoning with
circulators, return
temp over 130 °F
Zoning with zone
valves, return temp
over 130 °F
Piping for radiant
heating systems or
converted gravity
systems
Follow instructions on pages 14 and 15 to install near-boiler or single-zone piping. (Also
refer to
applicable.)
See
1. Size each circulator to individual circuit requirements.
2. Do not install circulator on boiler (except for primary/secondary piping).
3. Install isolation (balancing) valves to adjust flow to distribute heat to all zones.
4. Install and wire a separate relay for each zone circulator.
1. Install isolation (balancing) valves to adjust flow to distribute heat to all zones.
2. Provide a separate 24-volt transformer to power the zone valves. Size the transformer to
Converted gravity (or steam) systems
Whenever possible, use the primary/secondary piping shown in Figures 8 or 9 on page 19.
This piping design allows changing boiler flow rate without affecting primary circuit flow
rate.
If
11
the reduced flow rate in the heating system will not cause heat distribution problems.
Piping for radiant heating systems or converted gravity systems, below, if
Figure 6 or Figure 7 to complete installation.
handle the total rated load of all connected zone valves.
Figures 8 or 9 cannot be used, use the boiler-bypass piping shown in Figure 10 or Figure
on page 21. You can also use the piping shown in Figure 12 on page 23 (system-bypass), if
16
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.
Radiant heating systems
Preferably, use primary/secondary piping, as shown in Figures 8 or 9 on page 19. Alternatively,
use the method of either
12
(system-bypass), because this method does not control radiant system supply temperature.
If radiant system tubing has no oxygen barrier, a heat exchanger must be used.
Radiant heating system piping should include a means of regulating the boiler return water
temperature and the system supply temperature (such as provided by an injection pumping
control). Boiler return water temperature will be adequately controlled using the methods
shown in this manual provided the system supply temperature is relatively constant.
Do not apply the methods in this manual if the system is equipped with an outdoor reset
control
temperature at no less than 130 °F regardless of system supply temperature. Contact your
Weil-McLain representative for suggested piping and control methods. Failure to prevent
cold return water temperature to the boiler could cause corrosion damage to the sections or
burners, resulting in possible severe personal injury, death or substantial property damage.
. Instead, provide controls and piping which can regulate the boiler return water
Figure 10 or Figure 11 on page 21. Do not use the piping of Figure
Part number 550-110-260/0200
Boiler Manual
typical piping — multiple-zone installations
Figure 6
Zoning with circulators
— return water 130 °F or higher.
ZONE 2
ZONE 1
1
2
11
13
10
Cold
water
6
9
11
fill
12
Figure 7
Zoning with zone valves
— return water 130 °F or higher.
ZONE 2
ZONE 1
1
2
3
6
Cold
water
1
6
11
9
11
fill
12
6
Alternate
circulator
location
10
1
5
13
26012
1 Boiler isolation (balancing) valves
2 Flow/check valve
3 System or zone circulator
5 Zone valve
6 Drain valve
9 Relief valve
10 Automatic air vent (with diaphragm-type
expansion tank), or connect to tank fitting (closedtype expansion tank).
DO NOT use an automatic
For systems with possible low return-water temperature (such as converted gravity systems,
radiant heating systems and heat pump systems), refer to the special piping suggestions of
Figures 8 - 12, as applies. Failure to prevent sustained low return water temperature to the
boiler could cause corrosion of the boiler sections, resulting in severe personal injury, death
or substantial property damage.
Part number 550-110-260/0200
26013
air vent when using closed-type expansion tank. It
would allow air to leave the system, causing
waterlogging of the expansion tank.
11 Fill valve
12 Diaphragm-type or bladder-type expansion tank,
if used (For closed-type expansion tank, pipe from
top of air separator to tank fitting as in Figure 5.)
13 Air separator and automatic vent, if used (Note that
the fill valve must always be connected to the
expansion tank, regardless of location of expansion
tank circulator or air separator.
17
GOLD CGs Gas-Fired Water Boiler
Water piping — low temp systems3d
Primary/secondary
(preferred) bypass
piping method
Temperature gauges
Valve adjustment
(Figure 12 and 13 only)
Primary/secondary bypass piping is preferred because the flow rate and temperature drop in
the heating circuit(s) is determined only by the heating circuit circulator(s). So adjustment
of the bypass valves in the boiler circuit will not cause a change in the heating circuit rate and
temperature distribution.
Figures 8 and 9 show suggested bypass arrangements using primary/secondary bypass piping
(preferred) for low temperature systems such as radiant heating systems or converted gravity
systems
The bypass valves (items
system return water — set to assure a minimum return water temperature (at least 130 °F) to
the boiler. Set the valves as explained below.
Gauge 4a is suggested, but optional on any system.
Gauge
— to display the water temperature being supplied to the radiant tubing.
Gauge
a minimum of 130 °F. If this gauge is not available however, adjust the valves such that the
boiler-mounted temperature/pressure gauge reads at least 150 °F when the system return
water is cold (approximately 60 °F water temperature).
1. Set the valves while the system is cool, setting for the coldest expected water temperature
2. Start with valve 7a fully closed and 7b fully open.
3. Gradually open valve 7a while closing valve 7b until the temperature at gauge 8 reads
4. Note that valve
. For alternatives, see pages 20 through 23.
7a and 7b) provide mixing of hot boiler outlet water with cooler
4b is optional on converted gravity systems, but required on radiant heating systems
8 is required on all systems to assure the return water temperature is accurately set for
(usually 60 °F since the system will often drop to room temperature between cycles).
130 °F when gauge 4a reads 60 °F.
7a regulates the amount of hot water from the boiler supply which mixes
with return water. Valve 7b regulates the amount of system water flowing through the
boiler secondary loop.
18
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.
Radiant heating system piping should include a means of regulating the boiler return
water temperature
pumping control
Boiler return water temperature will be adequately controlled using the methods shown in
this manual provided the
DO NOT apply the methods of this manual if the system is equipped with an outdoor
reset control
water temperature at no less than 130 °F
your Weil-McLain representative for suggested piping and control methods.
Failure to prevent cold return water temperature to the boiler could cause corrosion
damage to the sections or burners, resulting in possible severe personal injury, death or
substantial property damage.
and the system supply temperature (such as provided by an injection
).
system supply temperature is relatively constant.
. Instead, provide controls and piping which can regulate the boiler return
regardless of system supply temperature. Contact
Part number 550-110-260/0200
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