Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Weil-McLain · Series
The AquaBalance was Weil-McLain Canada's stainless steel wall-mount condensing boiler, sold as a combi and a heat-only variant in 80/120/155 MBH sizes and listed on the CA Discontinued menu; the US still sells the Series 2 generation.
Series facts
CA page: up to 95% AFUE; the US Series 2 manual's AHRI table lists 95.0% AFUE for the AB-80/120/155.
Weil-McLain Canada lists the AquaBalance under Discontinued in two menu entries — AquaBalance (Combi) and AquaBalance (Heat Only) — both with 80, 120 and 155 MBH inputs, up to 95% AFUE and Category IV venting in PVC, CPVC, polypropylene or stainless steel. The CA pages describe a stainless steel wall-mount boiler for small spaces with 10:1 modulation.
The AquaBalance is one of the generation-gap products between the two countries: it remains current in the US as AquaBalance Series 2, documented by boiler manual 550-100-325/0924 with AB-80/120/155 heat-only and combi models, and that Series 2 manual's numeric A##/F## fault codes differ from the text-fault controls of the current CA ECO Tec, Simplicity, Evergreen and Ultra lines.
One spec note for owners: the CA discontinued page prints outputs of 73/109/143 MBH for the 80/120/155, while the US Series 2 manual's DOE heating capacities are 75/112/144 MBH — the CA page's figures trace to the earlier Canadian-era data, so manual references should be matched to the unit's generation.
Highlights
Models
One canonical page per model with input, output and efficiency kept separate.
Weil-McLain
The AB-80C is the combi entry of the AquaBalance Series 2 wall-mount line that weil-mclain.ca lists under Discontinued: 80 MBH CSA input, 75 MBH DOE heating capacity and an integrated DHW module at 95% AFUE in a 77 lb stainless steel unit.
Weil-McLain
The AB-120C is the mid-size AquaBalance Series 2 combi, discontinued in Canada: 120 MBH CSA input, 112 MBH DOE heating capacity and an integrated DHW module at 95% AFUE, in an 80 lb wall-mounted stainless steel unit.
Weil-McLain
The AB-155C is the flagship AquaBalance Series 2 combi, discontinued in Canada: 155 MBH CSA input, 144 MBH DOE heating capacity and the line's top DHW delivery — 4 GPM at a 70°F rise per the US page — at 95% AFUE in an 87 lb wall-mounted unit.
Weil-McLain
The AB-80H is the heat-only entry of the discontinued-in-Canada AquaBalance Series 2 line: 80 MBH CSA input, 75 MBH DOE heating capacity and a 65 MBH net AHRI rating at 95% AFUE in a 64 lb stainless steel wall-mount unit.
Weil-McLain
The AB-120H is the mid-size heat-only AquaBalance Series 2, discontinued in Canada: 120 MBH CSA input, 112 MBH DOE heating capacity and a 97 MBH net AHRI rating at 95% AFUE in a 67 lb stainless steel wall-mount unit.
Weil-McLain
The AB-155H tops the heat-only AquaBalance Series 2 line, discontinued in Canada: 155 MBH CSA input, 144 MBH DOE heating capacity and a 125 MBH net AHRI rating at 95% AFUE, still only 67 lb in the wall-mounted stainless steel cabinet.
| Specification | Weil-McLain AquaBalance AB-80C | Weil-McLain AquaBalance AB-120C | Weil-McLain AquaBalance AB-155C | Weil-McLain AquaBalance AB-80H | Weil-McLain AquaBalance AB-120H | Weil-McLain AquaBalance AB-155H |
|---|---|---|---|---|---|---|
| input-min | — | — | — | — | — | — |
| Input, maximum | 80 MBH | 120 MBH | 155 MBH | 80 MBH | 120 MBH | 155 MBH |
| DOE heating capacity | 75 MBH | 112 MBH | 144 MBH | 75 MBH | 112 MBH | 144 MBH |
| Efficiency (AFUE) | 95 % | 95 % | 95 % | 95 % | 95 % | 95 % |
| Turndown | 10:1 | 10:1 | 10:1 | 10:1 | 10:1 | 10:1 |
| vent-max-3 | — | — | — | — | — | — |
| vent-max-2 | — | — | — | — | — | — |
| Weight | 77 lb | 80 lb | 87 lb | 64 lb | 67 lb | 67 lb |
Read the full comparison: Weil-McLain AquaBalance AB-80C vs AB-80H →
Read the full comparison: Weil-McLain AquaBalance AB-80H vs AB-120C →
Read the full comparison: Weil-McLain AquaBalance AB-120C vs AB-120H →
Read the full comparison: Weil-McLain AquaBalance AB-120H vs AB-155C →
Error codes and alerts
Manuals
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.
Services for Weil-McLain boilers
No. Weil-McLain Canada lists both the AquaBalance combi and heat-only pages under Discontinued. The same platform remains current in the US as AquaBalance Series 2, so manuals and parts exist but are generation-specific.
Yes. The AquaBalance Series 2 manual documents numeric A## hard lockout codes and F## soft lockout codes — unlike the current ECO Tec, Simplicity, Evergreen and Ultra controls, which show text fault names.
The CA discontinued page lists outputs of 73/109/143 MBH while the US Series 2 manual lists DOE heating capacities of 75/112/144 MBH for the same nominal inputs. Owners should read ratings and parts lists against the generation on the rating plate.
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On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.