Weil-McLain CGa-8
The CGa-8 tops the CGa Series 4 range at 233 MBH CSA input with 198 MBH of DOE heating capacity, an 84% AFUE rating and a 7" vent — the largest of the cast iron line Canada discontinued in 2023.
Key figures
- Max input
- 233 MBH
- Max CSA output
- 198 MBH
- AFUE
- 84 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Weil-McLain CGa-8 in practice
The CGa-8 is the largest CGa Series 4 model: 233 MBH CSA input, 198 MBH of DOE heating capacity and a 172 MBH net AHRI rating at 84% AFUE, with the range's biggest 7" vent size. It belongs to the US-current generation of Weil-McLain's cast iron natural-draft gas-fired water boiler, which the Series 4 page equips with stainless steel burners, a built-in low water cut-off and service-friendly vertical flueways.
Canada's CGa line ended with the June 30, 2023 production cut-off Weil-McLain Canada announced on April 27, 2023 under federal efficiency standards; units sold only while supplies lasted and parts are promised for at least 20+ years. The CA discontinued-page data corresponds to the Series-3-era Canadian generation at 52-245 MBH inputs, so this Series 4 CGa-8 — the current US generation documented by manual 550-100-223/0425 — is recorded here with that generation split spelled out.
Best suited to
- The largest residential and light-commercial chimney-vented loads up to 233 MBH
- Contractors researching the top of the US CGa Series 4 range
- Documentation of large cast iron natural-draft boilers after the 2023 Canadian cut-off
Applicability and support
- Model number
- CGa-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 | 233 MBH | CSA input per the US Series 4 product page. |
| Output | ||
| DOE heating capacity | 198 MBH | DOE heating capacity per the US Series 4 product page. |
| Net AHRI water rating | 172 MBH | Net AHRI water rating per the US Series 4 product page. |
| Efficiency | ||
| Efficiency (AFUE) | 84 % | 84% AFUE per the US Series 4 page; the CA discontinued page lists up to 84% for the Series-3-era Canadian units. |
| Venting and air | ||
| Venting | Category I, B-vent — vertical chimney venting only, natural draft | Per the CA discontinued page (Cat. 1 venting, B-Vent; vertical vent only, 50 psi relief option); the US Series 4 page lists a 7" vent size for the CGa-8. |
| Operating limits and other | ||
| Fuel | Natural gas or propane | Propane requires a conversion kit per the CA product page. |
Manuals
- CGa Series 4 Boiler Manual, 550-100-223/0425550-100-223/0425 · 2025-04
Alerts documented for this model
- CONFIRM CONFIGURATION
- CONFIG MISMATCH
- AUTO LIMIT OPEN
- MANUAL LIMIT OPEN
- FALSE FLAME
- IGNITION FAULT
- FLAME LOST
- BOILER OUT OPEN
- BOILER OUT SHORT
- HARDWARE FAULT 1
- HARDWARE FAULT 2
- HARDWARE FAULT 3
- HARDWARE FAULT 4
- HARDWARE FAULT 5
- HARDWARE FAULT 6
- HARDWARE FAULT 7
- HARDWARE FAULT 8
- CH VOLTAGE HIGH
- DHW VOLTAGE HIGH
- SPILL SWITCH
Frequently asked questions
What are the CGa-8's ratings?
233 MBH CSA input, 198 MBH DOE heating capacity, a 172 MBH net AHRI rating and 84% AFUE, with a 7" vent size per the US Series 4 product page.
What happened to the CGa in Canada?
Weil-McLain Canada phased out the CGa with a production cut-off of June 30, 2023 under federal efficiency standards, per its April 27, 2023 news release; parts remain available for at least 20+ years.
Is the Series 4 CGa-8 a Canadian model?
No — the Series 4 set is the US-current generation. Canada's discontinued-page data describes the Series-3-era units at 52-245 MBH inputs, which is a different model set from the Series 4 range.
Questions about the Weil-McLain CGa-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 — CGa (discontinued) · accessed September 8, 2026
- Weil-McLain Canada — Residential boiler efficiency changes (Apr 27, 2023) · accessed September 8, 2026
- CGa Series 4 Boiler Manual 550-100-223/0425 · 550-100-223/0425 · accessed September 8, 2026
Facts checked September 8, 2026. Last updated September 8, 2026. Technical reviewer: not yet assigned.