Weil-McLain CGi-4
The CGi-4 is the mid-size CGi Series 5 model of the cast iron line discontinued in Canada in 2023: 90 MBH CSA input, 77 MBH DOE heating capacity and a 67 MBH net AHRI rating at 84% AFUE.
Key figures
- Max input
- 90 MBH
- Max CSA output
- 77 MBH
- AFUE
- 84 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Weil-McLain CGi-4 in practice
The CGi-4 fires at 90 MBH CSA input for 77 MBH of DOE heating capacity and a 67 MBH net AHRI rating at 84% AFUE. The US Series 5 page shows a 3" vent connection with 5" natural-draft venting for this size, on a cast iron boiler with insulated steel jacket, natural draft and direct exhaust capability, built-in low water cut-off and standard-component intermittent ignition.
Weil-McLain Canada discontinued the CGi in 2023: the April 27, 2023 news release set a June 30, 2023 production cut-off for mid-efficiency CGi and CGa hot water boilers under the federal efficiency standard, with parts promised for at least 20+ years. weil-mclain.ca's discontinued CGi page — inputs 50-233 MBH, up to 85.1% AFUE, chimney or sidewall venting — reflects the Series-3-era Canadian generation, so this Series 5 CGi-4 documents the US-current successor to those Canadian units.
Best suited to
- Homes whose heat-loss calculation lands around 90 MBH with chimney or sidewall venting
- Contractors verifying CGi Series 5 ratings against Canadian-era models
- Cast iron boiler replacement planning after the June 30, 2023 Canadian cut-off
Applicability and support
- Model number
- CGi-4
- 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 | 90 MBH | CSA input per the US Series 5 product page. |
| Output | ||
| DOE heating capacity | 77 MBH | DOE heating capacity per the US Series 5 product page. |
| Net AHRI water rating | 67 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 5" natural-draft venting for the CGi-4. |
| 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
What are the CGi-4's ratings?
90 MBH CSA input, 77 MBH DOE heating capacity, a 67 MBH net AHRI rating and 84% AFUE per the US Series 5 product page.
What generation of CGi was sold in Canada?
The Canadian discontinued-page data covers the Series-3-era units at 50-233 MBH inputs with up to 85.1% AFUE; the Series 5 set here (48-222 MBH, 84% AFUE) is the US-current generation.
Can I get parts for a Canadian CGi?
Weil-McLain Canada's phase-out notice states parts will be available for at least 20+ years from the June 30, 2023 production cut-off.
Questions about the Weil-McLain CGi-4?
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.