Description

The Weil-McLain CGa Gas Boiler Series 4 is a cast-iron, gas-fired hot-water boiler for homes heated with baseboard, radiators or in-floor hydronic tubing. It is a heating-only, non-condensing boiler that vents through a chimney and is rated at 84% AFUE in every size, from the CGa-25 (38,000 BTU/h input) to the CGa-8 (233,000 BTU/h input). It runs on natural gas or propane.

GSHA Services, LTD installs, services and repairs Weil-McLain boilers in McHenry County and Lake County, Illinois, the northern and western Chicago suburbs and southeastern Wisconsin. Weil-McLain equipment is purchased through local distributors. See our service area for the full list of communities.

Series note: Series 2 and Series 3 are earlier revisions of the CGa with the same model numbers and ratings. Weil-McLain’s current revision is CGa Series 4, which adds the Unity-CI control with a text screen, a 50 VA transformer and ENERGY STAR certification. GSHA services and repairs existing Series 2 and Series 3 units. For a new installation, your written estimate confirms the series supplied.

Who the Weil-McLain CGa Series 4 suits

The CGa is a good fit for a home with a hot-water (hydronic) heating system, an existing chimney in usable condition and a basement or utility space where a floor-standing boiler can sit. It is not a steam boiler: every CGa size is rated for hot-water heating only, so a home with steam radiators needs a boiler rated for steam. In the Weil-McLain line, the EG Series 7 is the cast-iron model rated for both water and steam; see its page for details. The CGa is also heating-only. Domestic hot water for showers and faucets comes from an indirect water heater connected to the boiler (the Series 4 control has an input for it) or from a separate water heater.

Sizing hint: the seven sizes carry net AHRI water ratings from 27,000 BTU/h (CGa-25) to 172,000 BTU/h (CGa-8). The net rating, not the input, is the number that must match your home’s heat loss. As a rough guide, the CGa-3 and CGa-4 cover many smaller homes and additions, the CGa-5 and CGa-6 cover typical two-story homes, and the CGa-7 and CGa-8 cover larger homes and those with more radiation. We size by a heat-loss calculation of your home, not by the nameplate on the old boiler, because older boilers were often oversized.

Benefits of the CGa Series 4 for your home

• Cast-iron sections. The heat exchanger is cast-iron sections rated to ASME 50 psig with a 30 PSI relief valve. Cast-iron sections tolerate the water conditions of older hydronic systems, which is one reason conventional cast-iron boilers tend to have a long service life.
• 84% AFUE in every size, ENERGY STAR certified. AFUE is the share of the gas you buy that becomes heat in the house over a season. The CGa is rated 84.0% in every size, and Series 4 carries ENERGY STAR certification.
• Uses your existing chimney. An atmospheric draft hood and automatic vent damper send flue gases up the chimney (4-inch to 7-inch vent depending on size). There is no sidewall vent to route through an exterior wall and no condensate drain to plumb, which keeps the installation simpler when the chimney is sound.
• Plain-language control with a built-in low-water cutoff. The Series 4 Unity-CI control shows boiler status on a text screen, and the built-in low-water cutoff with a test button protects the sections if the system loses water. It also has an aquastat input so an indirect water heater can run as a priority zone.
• Compact footprint. Jacket width runs from 10 inches (CGa-25 and CGa-3) to 25 inches (CGa-8), so the boiler fits in a utility room or a tight corner of the basement.

Weil-McLain CGa Series 4 price and free estimate

Every CGa size from the CGa-3 up has an installed package in our price book. The CGa-25 is available, but its installed price is set after a free on-site estimate.

Model	Input	DOE heating capacity	Net AHRI water rating	AFUE	Installed from
CGa-25	38,000 BTU/h	32,000 BTU/h	27,000 BTU/h	84.0%	Installed price after a free on-site estimate
CGa-3	67,000 BTU/h	56,000 BTU/h	48,000 BTU/h	84.0%	Installed from $8,712.51
CGa-4	100,000 BTU/h	85,000 BTU/h	73,000 BTU/h	84.0%	Installed from $9,006.05
CGa-5	133,000 BTU/h	113,000 BTU/h	98,000 BTU/h	84.0%	Installed from $9,427.86
CGa-6	166,000 BTU/h	141,000 BTU/h	122,000 BTU/h	84.0%	Installed from $9,997.36
CGa-7	200,000 BTU/h	170,000 BTU/h	147,000 BTU/h	84.0%	Installed from $10,487.50
CGa-8	233,000 BTU/h	198,000 BTU/h	172,000 BTU/h	84.0%	Installed from $11,007.18

Ratings are Weil-McLain’s published figures for the CGa. Input is the gas the burner uses; DOE heating capacity is the heat delivered to the water; the net AHRI rating is the heat available to the radiators after piping losses and pick-up, which is the number we match to your home.

Why the price is a “from” price. Every boiler installation is custom. The “from” price is the starting installed package for that CGa size with GSHA’s standard installation scope. The final price is confirmed by a free on-site estimate, because the following differ from home to home: chimney and venting condition (a chimney liner if one is needed), piping and zoning changes, circulators and zone valves, expansion tank and air separation, water-quality treatment, gas line capacity, electrical work, removal of the old boiler, permits and accessories. Accessories such as zone valves, additional circulators and an indirect water heater are priced separately. Financing available with approved credit; see financing.

Request a Boiler Installation Estimate  |  Schedule Boiler Repair  |  Call (224) 220-3660

Weil-McLain CGa Series 4 specifications

Specification	Value	Source
Boiler type	Cast-iron, gas-fired hot-water (hydronic) boiler; heating-only; hot water only (no steam sizes)	Weil-McLain CGa Series 4 product page; CGa Series 3 Boiler Manual 550-142-300
Series	CGa Series 4 (current); Series 2 and 3 are prior revisions with the same model numbers and ratings	weil-mclain.com product page and discontinued-products listing
Fuel	Natural gas (PIDN) or propane (PIDL)	Weil-McLain CGa product data
Condensing	No — atmospheric, natural draft	Weil-McLain CGa product data
AFUE	84.0% (all sizes)	Weil-McLain CGa Series 4 product page
Sizes and input	CGa-25, -3, -4, -5, -6, -7, -8: 38,000 to 233,000 BTU/h	Weil-McLain CGa Series 4 product page; Series 3 manual p.64-65
DOE heating capacity	32,000 to 198,000 BTU/h	Weil-McLain CGa Series 4 product page; Series 3 manual
Net AHRI water rating	27,000 to 172,000 BTU/h	Weil-McLain CGa Series 4 product page; Series 3 manual
Heat exchanger	Cast-iron sections, ASME 50 psig working pressure, 30 PSI relief valve	Weil-McLain CGa product data
Venting	Atmospheric draft hood and automatic vent damper to chimney; vent 4 in (CGa-25, CGa-3), 5 in (CGa-4), 6 in (CGa-5, CGa-6), 7 in (CGa-7, CGa-8)	Weil-McLain CGa product data
Ignition	Spark-ignited intermittent pilot	Weil-McLain CGa product data
Controls	Unity-CI control module with text screen; built-in low-water cutoff with test button; aquastat input for an indirect water heater; 50 VA transformer	Weil-McLain CGa Series 4 product page and sales flyer 0425
Dimensions	Jacket width 10 to 25 in; height 45-3/8 to 64-7/8 in; water content 1.5 to 4.4 gal	Weil-McLain CGa product data
Certification	ENERGY STAR certified (Series 4)	Weil-McLain CGa Series 4 sales flyer 0425
Manufacturer warranty (residential)	20-year heat exchanger, 2-year parts, labor not covered	Weil-McLain Model CG Limited Warranty for Residential Use 550-141-049

Shipping weight and supply/return tapping sizes: see the manufacturer’s product data.

Installation scope and warranty

What GSHA’s standard CGa installation includes. Set and level the boiler; new electrical disconnect, power wiring and control wiring; new connections to your existing supply and return piping; new cast-iron circulator; new 1/2-inch backflow preventer with autofill; new Discal air separator; new expansion tank; new hydronic docking station; new flue piping to your existing chimney; commissioning with Protector F1 and Cleaner F3 water treatment; new Honeywell T6 Pro hydronic thermostat; removal of the old boiler; start-up and safety inspection; and a boiler tune-up within the first year.

Why chimney venting matters here. Because the CGa is a non-condensing boiler, its flue gases stay hot and rise through a chimney. A condensing boiler, by contrast, has a stainless steel or aluminum heat exchanger, vents through plastic pipe out a sidewall and needs a condensate drain, which is why it can go almost anywhere but costs more to install. The CGa needs a chimney in good condition; if the flue is oversized, unlined or deteriorated, a chimney liner is added so the flue gases draft properly and do not damage the masonry. The estimate covers this.

Zoning and thermostats. Zones let different areas of the house call for heat separately, each with its own thermostat and a zone valve or circulator. Adding or changing zones is priced separately and is settled at the estimate.

Weil-McLain manufacturer warranty (residential use). Heat exchanger: 20 years from installation (years 1-5, replacement boiler; years 6-20, replacement heat exchanger). Parts: 2 years. Labor: not covered. The warranty is transferable and registration is not required. Terms are in the Weil-McLain Model CG Limited Warranty for Residential Use (550-141-049); improper sizing, installation or water conditions are excluded.

GSHA Install-Right Limited Boiler Warranty (GSHA’s own coverage). 2-year parts, 5-year labor and 20-year heat exchanger coverage on CGa boilers installed by GSHA Services, LTD. Labor coverage requires annual GSHA maintenance, and service by others voids GSHA labor coverage. Install-Right is separate from the Weil-McLain warranty above; both apply.

Annual tune-up. A yearly tune-up keeps the burners, pilot, vent damper and safety controls working as designed, checks the chimney draft and keeps both warranties in good standing. The first year’s tune-up is part of the installation package.

Weil-McLain CGa Series 4 FAQs

Do you install and repair Weil-McLain boilers in my city?

Yes, if you are in McHenry County or Lake County, Illinois, the northern or western Chicago suburbs or southeastern Wisconsin. GSHA Services, LTD installs, services and repairs Weil-McLain boilers from our Woodstock and Lake Bluff, Illinois locations. Check the service-area page or call (224) 220-3660.

Can my existing or discontinued Weil-McLain CGa boiler be repaired?

Yes. GSHA repairs existing CGa Series 2 and Series 3 boilers as well as Series 4. These earlier revisions share model numbers and ratings with the current series, and an older revision does not need to be replaced simply because a newer series exists. Use Schedule Boiler Repair to book a visit.

What is the difference between a combi boiler and a heating-only boiler?

A combi boiler is one appliance that heats the home and makes domestic hot water on demand; a heating-only boiler like the CGa heats the home only. A tankless water heater makes domestic hot water only and does not heat the home. With the CGa, domestic hot water comes from an indirect water heater, a storage tank heated by the boiler through its own zone, or from a separate water heater.

Is the CGa for steam or hot-water heating?

Hot water only. Every CGa size is a hydronic boiler that circulates heated water to baseboard, radiators or floor tubing. Steam systems heat by boiling water and sending steam to radiators, and they need a boiler rated for steam. The Weil-McLain EG Series 7 is the cast-iron model rated for both water and steam; see its page if you have steam radiators.

What does installation include and what can change the price?

The installed package covers the boiler, circulator, expansion tank, air separator, backflow preventer, wiring, flue piping to the chimney, water treatment, a Honeywell T6 Pro thermostat, removal of the old boiler, start-up and a first-year tune-up. The price changes with chimney condition and any liner, piping and zoning changes, extra circulators or zone valves, gas line capacity, electrical work, permits and accessories such as an indirect water heater. The free on-site estimate confirms the final price.

When does repair make more sense than replacement?

Repair usually makes sense when the boiler is in its first decade or so, the cast-iron sections are sound and the fault is a control, pilot, vent damper, circulator or gas valve. Replacement makes more sense when a section leaks, repairs are becoming frequent, parts are hard to get, or the boiler is badly oversized for the home. We tell you which applies after inspecting the boiler.

Which CGa size do I need?

The size that matches your home’s heat loss, which we calculate from the home’s construction, insulation, windows and the radiation installed. The net AHRI rating of the boiler should cover that heat loss with a small margin. Copying the old boiler’s nameplate often repeats an oversizing mistake that leads to short cycling and wasted fuel.

Can the CGa run on propane?

Yes. Weil-McLain offers the CGa for natural gas (PIDN) or propane (PIDL). Tell us which fuel you have when you request the estimate so the correct model is ordered.

Get a free estimate for a Weil-McLain CGa Series 4

Tell us about your home and heating system and we will visit, measure the heat loss, check the chimney and piping, and confirm the installed price in writing. Compare other current Weil-McLain models on the Weil-McLain boilers page, see the condensing GV90+ Series 2, or read about our boiler installation service. We also install Peerless and Navien boilers.

Request a Boiler Installation Estimate  |  Schedule Boiler Repair  |  Call (224) 220-3660