Weil-McLain CGi-8
The CGi-8 tops the CGi Series 5 range at 222 MBH CSA input with 189 MBH of DOE heating capacity — the largest of the cast iron line Canada discontinued in 2023, rated 84% AFUE.
Key figures
- Max input
- 222 MBH
- Max CSA output
- 189 MBH
- AFUE
- 84 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Weil-McLain CGi-8 in practice
The CGi-8 is the largest CGi Series 5 model: 222 MBH CSA input, 189 MBH of DOE heating capacity and a 164 MBH net AHRI rating at 84% AFUE, with the range's top natural-draft venting at 6" on a 3" vent connection. The US Series 5 page presents the boiler around cast iron sections and an insulated steel jacket, natural draft and direct exhaust capability, no vertical draft hood or mechanical vent damper, a built-in low water cut-off and intermittent electronic ignition with standard components.
Canada's CGi ended with the June 30, 2023 production cut-off announced by Weil-McLain Canada on April 27, 2023 under federal efficiency standards; units were available only while supplies lasted, with parts promised for at least 20+ years. weil-mclain.ca's discontinued CGi page (Series-3-era generation, inputs 50-233 MBH, up to 85.1% AFUE) predates this Series 5 set, so Boilers.ca records the US-current CGi-8 with the Canadian generation history flagged in the series record and on this page.
Best suited to
- The largest residential and light-commercial loads up to 222 MBH with chimney or sidewall venting
- Contractors researching the top of the US CGi Series 5 range
- Cast iron boiler documentation across the Canadian/US CGi generation split
Applicability and support
- Model number
- CGi-8
- 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 | 222 MBH | CSA input per the US Series 5 product page. |
| Output | ||
| DOE heating capacity | 189 MBH | DOE heating capacity per the US Series 5 product page. |
| Net AHRI water rating | 164 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 6" natural-draft venting for the CGi-8. |
| 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-8's ratings?
222 MBH CSA input, 189 MBH DOE heating capacity, a 164 MBH net AHRI rating and 84% AFUE per the US Series 5 product page.
What happened to the CGi in Canada?
Weil-McLain Canada phased out the CGi with a production cut-off of June 30, 2023 under federal efficiency standards, per its April 27, 2023 news release; remaining inventory sold only while supplies lasted.
Why does Boilers.ca show US Series 5 CGi models?
Weil-McLain Canada's discontinued page publishes no per-model ratings for the Series-3-era Canadian units, so Boilers.ca documents the current US Series 5 set from manual 550-100-629/0126 and the US product page.
Questions about the Weil-McLain CGi-8?
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.