Weil McLain GOLD CGS 4E User Manual

™

GOLD

CGs-4

Gas-Fired Water Boiler

• Installation • Maintenance

Boiler Manual

• Startup

• Parts

This manual must only be used by a qualiﬁed heating installer/service technician. Before installing, read all

instructions, including this manual, the burner manual and any related supplements. Perform steps in the order

given. Failure to comply could result in severe personal injury, death or substantial property damage.

DO NOT USE BOILER DURING CONSTRUCTION unless you provide dust-free air to the boiler area or

follow the requirements given on page 9. Failure to comply could result in severe personal injury, death or sub-

stantial property damage.

Part No. 550-110-282/1108

GOLD

CGs-4E Gas-Fired Water Boiler — Boiler Manual

^GOLDCGs-4E Gas-Fired Induced-Draft Water Boiler

Part number 550-110-282/1108

GOLD

CGs-4E Gas-Fired Water Boiler — Boiler Manual

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 ......................................................... 25

6 Field wiring ....................................................... 26

7 Start-up........................................................27–30

8 Check-out procedure......................................... 31

9 Operation .....................................................32–36

10 Service and maintenance .............................37–42

11 Troubleshooting............................................43–53

12 Replacement parts .......................................54–61

13 Dimensions and ratings................................62–63

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 dam-

age.

Indicates special instructions on installation, operation or maintenance that are important but

not related to personal injury or property damage.

Part number 550-110-282/1108

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Please read before proceeding

Installer

User

•

This manual is for use only by your qualiﬁed heating

Read all instructions before installing. Fol-

low all instructions in proper order to prevent

personal injury or death.

installer/service technician.

Please refer to the User’s Information Manual for your refer-

ence.

We recommend regular service by a qualiﬁed service techni-

cian, at least annually.

•

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.

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

on page 64 of this manual. Failure to comply could result in severe personal injury.

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 31.

Read and follow the special instructions for the Commonwealth of Massachusetts, located on page 36 of this

manual.

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. Min-

eral 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.

When servicing boiler —

•

To avoid electric shock, disconnect electrical supply before

performing maintenance.

•

To avoid severe burns, allow boiler to cool before perform-

ing maintenance.

Boiler operation —

•

Do not add cold water to hot boiler. Thermal shock can

cause sections to crack.

•

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.

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:

•

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.

•

Never store glycol of any kind near the boiler or any poten-

tial ignition source.

Boiler water —

•

Donotusepetroleum-basedcleaningorsealingcompounds

in boiler system. Water seal deterioration will occur, caus-

ing leakage between sections. This can result in substantial

property damage.

Monitor and inspect the system and boiler regularly for

leakage. Repair any leaks immediately to prevent possible

accumulation of glycol.

•

Do not use“homemade cures”or“boiler patent medicines”.

Severe personal injury, death or substantial property dam-

age may result.

•

Never use automotive antifreeze or ethylene glycol in the

system. Using these glycols can lead to hazardous leakage

of glycol in the boiler system.

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Prepare boiler location — codes & checklist

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 Electri-

cal Code Part 1 and any local codes.

The CGs-4E 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 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, or other contaminants.

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.

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Prepare boiler location — clearances

Recommended SERVICE clearances

Figure 2

Required MINIMUM clearances

(Fig. 1)

1. Provide clearances for cleaning and servicing the boiler and for

access to controls and components. See Figure 1 for recommenda-

tions.

2. Provide at least screwdriver clearance to jacket front panel screws

for removal of front panel for inspection and minor service. If

unable to provide at least screwdriver clearance, install unions and

shutoff valves in system so boiler can be moved for servicing.

Figure 1

Recommended

SERVICE clearances

(see WARNING

below)

Flooring

The CGs-4E boiler is approved for installation on combus-

tible ﬂooring, but must never be installed on carpeting.

If any clearance is less than in Figure 1, provide

openings for combustion and ventilation air

located on the wall or door opposite the boiler

FRONT (see Figure 2).

Do not install boiler on carpeting even

if foundation is used. Fire can result,

causing severe personal injury, death

or substantial property damage.

These openings must be located as shown in Figure 2 to provide

proper air ﬂow around the boiler. The free area of each opening

(after deducting for louvers) must be at least one square inch per

1,000 Btuh of boiler input. If the building is of unusually tight

construction (see page 10 for deﬁnition), the air openings must

connect directly to outside or the building must have air openings

to the outside as speciﬁed on page 10.

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.

If clearances are equal to or greater than Figure 1, see pages 10

and 11 for location and sizing of combustion air openings.

2. Minimum dimensions are 25” length by:

Minimum foundation width:

Failure to comply can result in severe personal injury, death or

substantial property damage and reduced boiler life.

CGs-4E

15”

Required MINIMUM clearances (Fig. 2)

Never install the boiler in a space with clear-

ances less than the minimum clearances shown

in Figure 2. Failure to comply can result in severe

personal injury, death or substantial property

damage and reduced boiler life.

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:

1. Hot water pipes: at least ¹⁄₂ inch from combustible material.

•

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.

2. Single-wall vent pipe: at least 6 inches from combustible mate-

rial.

3. Type B double-wall metal vent pipe: refer to vent manufacturer’s

•

Locate or protect the boiler so it cannot be damaged

recommendation for clearances to combustible material.

by a moving vehicle.

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Prepare boiler location — vent system

Failure to follow all instructions can result in ﬂue gas spillage and carbon monoxide emissions, causing severe

personal injury or death.

Inspect existing chimney before installing boiler. Failure to clean or replace perforated pipe or tile lining will cause

severe personal injury or death.

DO NOT COMMON VENT — Do not install the CGs-4E 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.

When removing boiler from an CGs-4E special vent system

existing common vent system:

At the time of removal of an existing boiler, the fol-

Vent system

The CGs-4E boiler requires a special vent system, de-

signed for pressurized venting. Model CGs-4E is rated

ANSI Z21.13 Category IV (pressurized vent, likely to

condense in the vent).

lowing steps shall be followed with each appliance

remaining connected to the common venting system

placed in operation, while the other appliances remain-

ing connected to the common venting system are not

in operation.

You may use any of the vent systems covered by the

CGs Venting Supplements included in the envelope as-

sembly. The CGs vent starter is a special item, designed

only for CGs and CGs-4E boilers, available from each

vendor. Do not attempt to connect the vent to the CGs-

4E boiler with any other means.

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 condi-

tion.

DO NOT mix components from

different systems. The vent system

could fail, causing leakage of ﬂue

products into the living space.

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 con-

nected to the common venting system are located

and other spaces of the building. Turn on clothes

dryers and any appliance not connected to the com-

mon 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 sum-

mer exhaust fan. Close ﬁreplace dampers.

Vent termination and combustion air

supply

The CGs-4E boiler may be vented through the roof or

through a side wall. Follow the appropriate vent supple-

ment for the vent system chosen. The maximum vent

length depends on boiler size. Refer to the vent supple-

ment to determine acceptable vent length.

d. Place in operation the appliance being inspected.

Follow the lighting/operating instructions. Adjust

thermostat so appliance will operate continuously.

Combustion air for the CGs-4E boiler must be 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:

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 previ-

ous conditions of use.

1. Vertical direct vent installation. Obtain the

Weil-McLain Through-Roof or Through-Unused

Chimney termination kit and supplement. Refer

to Vertical Direct Venting Venting Supplement,

packed with the kit, and to the vent manufacturer’s

instructions for the vent material chosen.

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.

2. Sidewall direct vent installation. Use the Vent/Air

Intake termination kit shipped with the boiler. Refer

to CGs DirectVenting: Sidewall & Direct Exhaust

Venting:Vertical or Sidewall Venting Supplement

shipped with the boiler.

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Prepare boiler location — contamination

Please review the following information on potential Refer to Table 1 for products and areas which may cause

combustion air contamination problems.

contaminated combustion air.

All CGs-4E boilers must be direct vented (using ducted outside air).The vent/air termination

must be installed in a location that is free of the contaminants listed below. Allowing the

boiler to operated with contaminated air can cause damage to the boiler and vent system,

resulting in possible severe personal injury, death or substantial property damage.

Table 1 Corrosive or destructive contaminants and likely locations

Products to avoid

Areas likely to have contaminants

Spray cans containing chloro/fluorocarbons

Permanent wave solutions

Dry cleaning/laundry areas and establishments

Swimming pools

Chlorinated waxes/cleaners

Metal fabrication plants

Chlorine-based swimming pool chemicals

Calcium chloride used for thawing

Sodium chloride used for water softening

Refrigerant leaks

Beauty shops

Refrigeration repair shops

Photo processing plants

Auto body shops

Paint or varnish removers

Plastic manufacturing plants

Furniture refinishing areas and establishments

New building construction

Remodeling areas

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

Garages with workshops

Adhesives used to fasten building products and

other similar products

Buildings under construction (where air is

contaminated with particulates)

Airborne particulates (drywall dust, fiberglass

particles, road or gravel dust, lint, etc.)

CONSTRUCTION DUST HAZARD — Airborne particulates, such as drywall dust or

ﬁberglass dust, will cause blockage of the CGs-4E burners, resulting in carbon monoxide

production, a ﬁre hazard, or building freeze damage. If the boiler is operated during

construction, you must isolate the boiler air supply to provide clean air for combus-

tion. Follow the instruction manual guidelines for piping intake air. If you are unable

to ensure uncontaminated air in the boiler air intake at all times, you must inspect

the boiler at least once weekly. When inspecting, clean the burners if necessary using

the procedure given on page 39. Failure to follow these guidelines could result in severe

personal injury, death or substantial property damage.

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Prepare boiler location — air openings

Louver allowance

Air opening location and sizing requirements de-

pend on the clearances around the boiler. Check

the boiler placement compared to Figure 1, page 7.

The free area of openings means the area after reduc-

tion for any installed louvers or grilles. Be sure to

consider this reduction when sizing the air openings.

If all clearances are at least equal to Figure 1,

page 7, apply the sizing and placement of openings

given on pages 10 and 11.

✷

If ANY clearance is less than Figure 1, page 7,

you must provide air openings sized and located

as shown in Figure 2, page 7. DO NOT apply the

sizing and location information shown on page 10

or 11. The Figure 2 air openings are required even if

the boiler is direct vented (outside air piped to the

boiler air intake as described in this manual). These

openings ensure adequate air circulation around the

boiler for cooling, even if the boiler does not use

inside air for combustion.

Special considerations

Tight construction

ANSI Z223.1 defines unusually tight construction

where:

1. Walls and ceilings exposed to the outside atmo-

sphere have a continuous water vapor retarder with

a rating of 1 perm or less with openings gasketed,

and . . .

2. Weather-stripping has been added on openable

windows and doors, and . . .

3. 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.

Combustion air requirements

✷

Using outside air — direct vent only

Combustion air must be ducted directly from outside to the CGs-4E boiler

air intake ﬁtting. This method is deﬁned as direct vent (also referred to

as sealed 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.

For buildings with such construction, provide air open-

ings into the building from outside, sized per the ap-

propriate case in Figure 3 if appliances are to use inside

air for combustion and ventilation.

Exhaust fans and air movers

Sizing air openings

Air openings provide for ventilation to prevent overheating of the boiler

controls and boiler space. Air is also needed for other appliances located

in the same space.

✷

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 dimen-

sions 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.

Use Figure 3,page 11,selecting the appropriate installation conditions.Note

that the sizing given in Figure 3 applies only to CGs-4E 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.

Motorized air dampers

If the air openings are ﬁtted with motorized dampers,

electrically interlock the damper to:

Air openings must be sized to handle all appliances and

air movers (exhaust fans, etc.) using the air supply.

•

Prevent the boiler from ﬁring if the damper is not

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-4E boiler is rated Category IV (pressurized vent),

and has different requirements for combustion and ventilation air, reﬂected

fully open.

•

Shut the boiler down should the damper close dur-

ing boiler operation.

by the special sizing instructions given in Figure 3. The air openings rec- To accomplish this interlock, wire an isolated contact

ommended in Figure 3 will allow adequate ventilation and combustion (proving the damper open) in series with the thermo-

air provided the boiler room is not subjected to negative pressure due to stat input to the boiler. The boiler will not start if this

exhaust fans or other mechanical ventilation devices. Refer to the National contact is open, and will shut down should it open

Fuel Gas Code for dealing with other conditions.

during operation.

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Figure 3 Sizing air openings for CGs-4E installations ✷

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Prepare boiler — placement & setup

Inlet air box top panel must be in

Place boiler/crate near

position

position during boiler operation.

Failure to do so could result in

severe personal injury, death or

substantial property damage.

1. Leave boiler in crate and on pallet until installation

site is ready.

2. Move entire crate and pallet next to selected loca-

tion.

3. Remove crate.

4. Remove boiler from pallet.

Oriﬁce replacement procedure

Do not drop boiler or bump jacket

on ﬂoor or pallet. Damage to boiler

can result.

(when required)

1. Remove the screws securing the inlet air box top

panel.

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 posi-

tion.

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.

5. Check level.

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 tap-

pings.

a. Shim legs, if necessary.

b. Do not alter legs.

Inspect oriﬁces and burners

1. Remove front jacket door. Remove inlet air box top

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 per-

sonal injury, death or substantial

property damage.

panel (see Figure 27, item 13, page 56).

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,

death or substantial property dam-

age.

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 8 page 31,

to assure the boiler is now operating properly after

oriﬁces are replaced.

3. Reinstall inlet air box top panel.

Table 2 Manifold oriﬁce sizing

Location

U. S.

Natural gas

Propane gas

0-2,000 ft

over 2,000 ft

(Note 1)

0-2,000 ft

1.60 mm

0-2,000 ft

1.60 mm

over 2,000 ft

(Note 1)

2.55 mm

0-2,000 ft

2.55 mm

2,000-4,500

#41

2,000-4,500

1.45 mm

Canada

Note 1: For elevations above 2,000 feet, contact your local Weil-McLain sales ofﬁce for details.

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Prepare boiler — pressure test

5. Slowly reopen boiler drain valve until test pressure

Hydrostatic pressure test

on the pressure/temperature gauge reaches no more

than:

Pressure test boiler before attaching water or gas piping

(except as noted below) or electrical supply.

•

45 psig for boilers with 30 psig relief valve.

Prepare boiler for test

75 psig for boilers with 50 psig relief valve.

1. Remove the shipping nipple (from CGs-4E supply

tapping) and remove the boiler relief valve. Tempo-

rarily plug the relief valve tapping with a ¾” NPT

pipe plug.

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.

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 29, page 60. Install

circulator on either the return or supply.

3. Remove 1¼” nipple, 1¼” x 1¼” x ½” tee and pres-

sure/temperature gauge from circulator hardware

and pressure/temperature gauge carton. Pipe to

boiler supply connection as shown on page 3 and

Figure 29, page 60. (Use pipe dope sparingly.)

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 main-

tained 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.

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.)

Do not use petroleum-based clean-

ing or sealing compounds in boiler

system. Severe damage to boiler

will occur, resulting in substantial

property damage.

6. Connect a nipple and shutoff valve to system re-

turn 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.)

Drain and remove ﬁttings

1. Disconnect ﬁll water hose from water source.

Fill and pressure test

2. Drain boiler at drain valve or out hose, whichever

provides best access to drain. Remove hose after

draining if used to drain boiler.

1. Open the shutoff valves you installed on supply and

return connections.

2. Slowly open boiler drain valve and fresh water sup-

ply to ﬁll boiler with water.

3. Remove nipples and valves unless they will remain

for use in the system piping.

3. When water ﬂows from shutoff valves, close boiler

drain valve.

4. Remove plug from relief valve tapping. See page 14

4. Close shutoff valves.

to replace relief valve.

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Water piping — general information

General piping information

Circulator

If installation is to comply with ASME or Canadian requirements, an ad-

ditional 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, page 34 for wiring.

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 instal-

lation. Pipe the expansion tank to the suction side of the

circulator whenever possible. Install an air separator in

A low water cutoff device is required when boiler is installed above ra- the supply piping.Connect the expansion tank to the air

diation 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.

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,page 15, show typical near-

boiler piping connections.

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

codes.

System water piping

Pressure/temperature gauge

Install pressure/temperature gauge in tee on supply piping (as shown in

drawing on page 3).

See Figure 4 (diaphragm-type or bladder-type expan-

sion tank) or Figure 5 (closed-type expansion tank) on

page 15, and Table 3 below, for near-boiler 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 (large-volume

systems originally designed for circulation by natural

convection rather than a pump).

Relief valve

Install relief valve vertically in ¾” tapping on side of boiler. See Figure 4 or 5,

page 15, and the tag attached to the relief valve for manufacturer’s instructions.

Table 3 Water pipe size (based on 20°F rise)

To avoid water damage or scalding due to relief valve

operation:

Boiler

model

system

From

system

•

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.

number

CGs-4E

1”

•

Discharge line must be as short as possible and be the same size as

the valve discharge connection throughout its entire length.

Note: The boiler supply and return connections, the return/

drain tee and the supply/gauge tee supplied with

the boiler are 1¼” NPT. One of the circulator ﬂanges

supplied with the boiler is 1¼”. The other circulator

ﬂange is the size of the recommended system piping

shown above.

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 mate-

rial serviceable for temperatures of 375°F or greater.

Do not pipe the discharge to any place where freezing could

occur.

Chillers or air handling units:

Install boiler such that —

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.

•

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 au-

tomatic 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.

•

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.

Part number 550-110-282/1108

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Water piping — single-zone system

Diaphragm-type or bladder-

type expansion tank ^{(Figure 4)}

Closed-type expansion tank

(Figure 5)

1. Ensure expansion tank size will handle boiler and 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.

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.

2. Install an automatic air vent in air vent tapping as

shown.

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.

Figure 4

Diaphragm- or bladder-type expansion tank

Piping to single-zone system

See Table 3 for piping sizes.

Figure 5

Closed-type expansion tank

Piping to single-zone system

See Table 3 for piping sizes.

Part number 550-110-282/1108

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Water piping — multiple zones

Piping multiple zones

Piping for radiant heating

Follow instructions on pages 14 and 15 to install near-

boiler or single-zone piping. (Also refer to Piping for

radiant heating systems or converted gravity sys-

tems, below, if applicable.)

systems or converted gravity

systems

Converted gravity (or steam) systems

See Figure 6 or Figure 7, page 17, to complete instal-

lation.

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 pri-

mary circuit ﬂow rate.

Zoning with circulators (Figure 6)

(return temp over 130°F)

If Figures 8 or 9 cannot be used, use the boiler-bypass

piping shown in Figure 10 or Figure 11 on page 21.You

can also use the piping shown in Figure 12 on page 23

(system-bypass), if the reduced ﬂow rate in the heating

system will not cause heat distribution problems.

1. Size each circulator to individual circuit require-

ments.

2. Do not install circulator on boiler (except for pri-

mary/secondary piping).

3. Install isolation (balancing) valves to adjust ﬂow to

distribute heat to all zones.

Failure to prevent low return water

temperature to the boiler could

cause corrosion of the boiler sec-

tions or burners, resulting in severe

personal injury, death or substantial

property damage.

4. Install and wire a separate relay for each zone cir-

culator.

Zoning with zone valves (Figure 7)

(return temp over 130°F)

Radiant heating systems

1. Install isolation (balancing) valves to adjust ﬂow to

distribute heat to all zones.

Preferably, use primary/secondary piping, as shown

in Figures 8 or 9 on page 19. Alternatively, use the

method of either Figure 10 or Figure 11 on page 21.

Do not use the piping of Figure 12 (system-bypass),

because this method does not control radiant system

supply temperature.

2. Provide a separate 24-volt transformer to power the

zone valves. Size the transformer to handle the total

rated load of all connected zone valves.

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. Instead, provide controls and piping which can regulate the boiler return water

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 dam-

age.

Part number 550-110-282/1108

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Water piping — multiple zones

(continued)

Figure 6

Zoning with circulators

— return water 130°F or higher.

Figure 7

Zoning with zone valves

— return water 130°F or higher.

Boiler isolation (balancing) 10 Automatic air vent (with diaphragm-type expansion tank), or connect

valves

to tank ﬁtting (closed-type expansion tank). DO NOT use an automatic

air vent when using closed-type expansion tank. It would allow air to

leave the system, causing waterlogging of the expansion tank.

Flow/check valve

System or zone circulator

Zone valve

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, page 15.)

Drain valve

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.

Relief valve

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 550-110-282/1108

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Piping — low temp systems

the water temperature being supplied to the radiant

tubing.

Primary/secondary (preferred)

bypass piping method

Gauge 8 is required on all systems to assure the return

water temperature is accurately set for a minimum of

130°F. If this gauge is not available however, adjust the

valves such that the boiler-mounted temperature/pres-

sure gauge reads at least 150°F when the system return

water is cold (approximately 60°F water temperature).

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, page 19, show suggested bypass ar- Valve adjustment

rangements using primary/secondary bypass piping

(preferred) for low temperature systems such as radiant

heating systems or converted gravity systems. For

alternatives, see pages 20 through 23.

(Figures 8 and 9 only)

1. Set the valves while the system is cool,setting for the

coldest expected water temperature (usually 60°F

since the system will often drop to room tempera-

ture between cycles).

The bypass valves in Figures 8 and 9 (items 7a and 7b)

provide mixing of hot boiler outlet water with cooler

system return water — set to assure a minimum return

water temperature (at least 130°F) to the boiler. Set the

valves as explained below.

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 130°F when gauge

4a reads 60°F.

Temperature gauges

4. Note that valve 7a regulates the amount of hot wa-

ter from the boiler supply which mixes with return

water.Valve 7b regulates the amount of system water

ﬂowing through the boiler secondary loop.

Gauge 4a is suggested, but optional on any system.

Gauge 4b is optional on converted gravity systems,

but required on radiant heating systems — to display

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 and the system supply temperature (such as provided by an injec-

tion 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 of this manual if the system is equipped with an outdoor

reset control. Instead, provide controls and piping which can regulate the boiler re-

turn water 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.

Part number 550-110-282/1108

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Piping — low temp systems

(continued)

Figure 8

Primary/secondary piping

Zoning with circulators

Figure 9

Primary/secondary piping

Zoning with zone valves

9 Relief valve

Boiler isolation (balancing) valves

Flow/check valve

10 Automatic air vent (with diaphragm-type expansion tank), or

connect to tank ﬁtting (closed-type expansion tank). DO NOT

use an automatic air vent when using closed-type expansion

tank. It would allow air to leave the system, causing waterlog-

ging of the expansion tank.

System or zone circulator

System temperature gauges

Zone valve

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, page 15.)

Drain valve

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.)

System temperature valves (see instruc-

tions to the left for adjusting valves)

Blend temperature gauge

Part number 550-110-282/1108

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CGs-4E Gas-Fired Water Boiler — Boiler Manual

Piping — low temp systems

(continued)

justed using cold (or room temperature) return water

to the boiler. (When setting the valves without gauge

4a installed — using cold or room temperature water

— assume the return water temperature to be 60°F. Set

the valves so gauge 8 reads at least 120°F.

BOILER-bypass piping

method

This piping method (Figures 10 and 11, page 21) is

called a boiler-bypass because part of the circulator

ﬂow is bypassed around the boiler (through valve 7a).

This method reduces the ﬂow rate throughout the boiler,

in order to raise the average water temperature in the

boiler enough to prevent ﬂue gas condensation. Boiler-

bypass piping is effective for some boilers — including

the CGs-4E — provided the ﬂow rates are adjusted

according to the instructions following.

Gauge 4b is optional on converted gravity systems,

but required on radiant heating systems — to display

the water temperature being supplied to the radiant

tubing.

Gauge 8 is required on all systems to assure reliable

adjustment of the bypass valves. The boiler-mounted

temperature/pressure gauge can be used if a separate

temperature gauge is not installed.

Figures 10 and 11 are alternative piping suggestions

for converted gravity (large water content or steam

systems) or radiant heating system — for use when

primary/secondary piping can’t be applied. (Figure 12,

page 23, is another alternative, using system bypass in

place of boiler-bypass piping. Figure 12 however, is

not suitable for radiant heating applications because it

does not protect the radiant system from possible high

water temperature.)

Valve adjustment

1. Start with valve 7a fully closed and 7b fully open.

2. Gradually open valve 7a while closing valve 7b

until the temperature at gauge 8 reads 60 °F higher

than gauge 4a. A minimum 60°F temperature rise

through the boiler assures a low enough ﬂow rate

and high enough average temperature to prevent

condensation even with low system return water

temperature.

Boiler-bypass piping keeps system ﬂow rate as high as

possible and temperature drop as low as possible, help-

ing to equalize the building heat distribution.

3. Valve 7a regulates the system ﬂow rate, while valve

7b regulates the boiler ﬂow rate.

Temperature gauges

Gauge 4a is optional if the bypass valves will be ad-

4. The boiler-mounted temperature/pressure gauge

may be used in place of a separate gauge 8.