Weil-McLain CGi-25
The CGi-25 is the smallest CGi Series 5 size, from the cast iron line Canada discontinued in 2023: 48 MBH CSA input, 41 MBH DOE heating capacity and a 36 MBH net AHRI rating at 84% AFUE.
Key figures
- Max input
- 48 MBH
- Max CSA output
- 41 MBH
- AFUE
- 84 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Weil-McLain CGi-25 in practice
The CGi-25 opens the seven-model CGi Series 5 range at 48 MBH CSA input with 41 MBH of DOE heating capacity and a 36 MBH net AHRI rating at 84% AFUE. The US Series 5 page describes the generation as a cast iron gas-fired water boiler with an insulated steel jacket, natural draft and direct exhaust capability, no vertical draft hood and no mechanical vent damper, built-in low water cut-off and intermittent electronic ignition, on a 3" vent connection with 4" natural-draft venting for this size.
Weil-McLain Canada discontinued the CGi alongside the CGa with a production cut-off of June 30, 2023 under federal efficiency standards, per its April 27, 2023 news release — sales continued only while stock lasted, and parts are promised for at least 20+ years. weil-mclain.ca's discontinued CGi page reflects the Series-3-era Canadian units (inputs 50-233 MBH, up to 85.1% AFUE), a different model set from the Series 5 line documented here, which Weil-McLain continues to sell in the US.
Best suited to
- Smaller homes with chimney or sidewall venting needs near 48 MBH of input
- Contractors documenting the US-current CGi Series 5 generation after the 2023 cut-off
- Research on the cast iron CGi line that succeeded the Canadian-era units in US markets
Applicability and support
- Model number
- CGi-25
- 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 | 48 MBH | CSA input per the US Series 5 product page. |
| Output | ||
| DOE heating capacity | 41 MBH | DOE heating capacity per the US Series 5 product page. |
| Net AHRI water rating | 36 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-25. |
| 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
Is the CGi still sold in Canada?
No. Weil-McLain Canada set a production cut-off of June 30, 2023 for the CGi under federal efficiency standards, per its April 27, 2023 news release; inventory sold only while supplies lasted and parts are promised for at least 20+ years.
Does the CGi produce domestic hot water?
Neither the discontinued CA page nor the US Series 5 page lists a combi or tankless-coil option for the CGi — Boilers.ca records it with combi: false, matching how the files document the series.
What are the CGi-25's ratings?
48 MBH CSA input, 41 MBH DOE heating capacity, a 36 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-25?
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.