Weil-McLain CGi-3
The CGi-3 is the second-smallest CGi Series 5 size of the cast iron line Canada discontinued in 2023: 58 MBH CSA input, 49 MBH DOE heating capacity and a 43 MBH net AHRI rating at 84% AFUE.
Key figures
- Max input
- 58 MBH
- Max CSA output
- 49 MBH
- AFUE
- 84 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Weil-McLain CGi-3 in practice
The CGi-3 fires at 58 MBH CSA input for 49 MBH of DOE heating capacity and a 43 MBH net AHRI rating at 84% AFUE. It belongs to the current US CGi Series 5 generation — cast iron sections with an insulated steel jacket, natural draft and direct exhaust vent capability, no vertical draft hood or mechanical vent damper, built-in low water cut-off and intermittent electronic ignition — vented through a 3" connection with 4" natural-draft sizing on this model.
The CGi is one of the two mid-efficiency cast iron lines Weil-McLain Canada phased out under the federal efficiency standard: its April 27, 2023 news release set a June 30, 2023 production cut-off, with boilers sold only while inventory lasted and 20+ years of parts support promised. The discontinued CA page's data (50-233 MBH inputs, up to 85.1% AFUE, Cat. 1 B-vent/Cat. 3 AL29-4C venting) covers the Series-3-era Canadian generation, while the Series 5 models recorded here are the US-current set.
Best suited to
- Homes with loads near 58 MBH that can vent to a chimney or sidewall
- Contractors mapping CGi generations between the Canadian and US markets
- Replacement documentation for smaller cast iron CGi boilers
Applicability and support
- Model number
- CGi-3
- Canadian availability
- historical
- Production status
- discontinued
- ROMA supplies
- Confirmed at consultation
- ROMA services
- Confirmed at consultation
- Warranty
- Not verified
Where ROMA provides on-site service
On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.
Specifications
Published specifications
Values as published by Weil-McLain. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input, maximum | 58 MBH | CSA input per the US Series 5 product page. |
| Output | ||
| DOE heating capacity | 49 MBH | DOE heating capacity per the US Series 5 product page. |
| Net AHRI water rating | 43 MBH | Net AHRI water rating per the US Series 5 product page. |
| Efficiency | ||
| Efficiency (AFUE) | 84 % | 84% AFUE per the US Series 5 page; the CA discontinued page lists up to 85.1% for the Series-3-era Canadian units. |
| Venting and air | ||
| Venting | Category I B-vent (chimney) or Category III AL29-4C stainless steel (sidewall) | Per the CA discontinued page, which notes Category I vent sizes increase from 3" to 4" up to the CGi-3 size and 3" to 5" on larger sizes; the US Series 5 page lists a 3" vent connection with 4" natural-draft venting for the CGi-3. |
| Operating limits and other | ||
| Fuel | Natural gas or propane | Propane requires a conversion kit per the CA product page. |
Manuals
- CGi Series 5 Boiler Manual, 550-100-629/0126550-100-629/0126 · 2026-01
Alerts documented for this model
Frequently asked questions
When was the CGi discontinued in Canada?
Weil-McLain Canada's April 27, 2023 news release set a production cut-off of June 30, 2023 for the CGi and CGa; the CGi sold only while stock lasted, with parts available for at least 20+ years.
What venting does the CGi use?
The CA discontinued page lists chimney venting (Category I, B-vent) or sidewall venting (Category III, AL29-4C stainless), noting Category I vent sizes increase from 3" to 4" up to the CGi-3 and 3" to 5" on other sizes.
What are the CGi-3's ratings?
58 MBH CSA input, 49 MBH DOE heating capacity, a 43 MBH net AHRI rating and 84% AFUE, with a 3" vent connection per the US Series 5 product page.
Questions about the Weil-McLain CGi-3?
Describe what the boiler is doing and get a straight answer about the next step.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
- Weil-McLain Canada — CGi (discontinued) · accessed September 8, 2026
- Weil-McLain Canada — Residential boiler efficiency changes (Apr 27, 2023) · accessed September 8, 2026
- CGi Series 5 Boiler Manual 550-100-629/0126 · 550-100-629/0126 · accessed September 8, 2026
Facts checked September 8, 2026. Last updated September 8, 2026. Technical reviewer: not yet assigned.