Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Dunkirk Boilers · Series
The Q90 pages cover Dunkirk's two legacy condensing series: the Q90 Series 4 (Q90-050/075/100, 90% AFUE cast aluminum heat exchanger, HSI ignition with a Hydrolevel combination high-limit/LWCO control with reset) and the Q90-200 Series II (125–200 MBH on the cast aluminum monoblock heat exchanger with the Fuel Smart Hydrostat). Both product pages show zero current documents, so Boilers.ca records them as legacy hubs.
Series facts
90% AFUE as printed on both Q90 pages: the Q90 Series 4 page opens 'The Q90 Series 4 condensing gas boiler offers a 90% AFUE rating...' and the Q90-200 page 'The Q90-200 Series II offers a 90% AFUE efficiency rating...'; both lines are ENERGY STAR rated.
The Q90 family is the Dunkirk twin of Utica's UB90 condensing line: Q90 Series 4 sizes of 50, 75 and 100 MBH on a high-efficiency cast aluminum heat exchanger with low pressure drop, hot surface ignition (HSI), a Hydrolevel combination high limit/low water cut-off control with boiler water temperature reset, a stainless steel premix burner, sealed combustion, polypropylene venting approval and an induced draft blower with adjustable exhaust (front, right side or rear) — the page prints 50, 75, 100 MBH capacities, a 90% AFUE rating and a 15-year limited warranty. The Q90-200 Series II page covers the larger 125–150–175–200 MBH sizes on the cast aluminum monoblock heat exchanger with the Fuel Smart Hydrostat (temperature limit, LWCO and boiler reset in one control), vented in CPVC and PVC, also at 90% AFUE with a limited 15-year warranty.
Status as printed: neither Q90 page appears in the current category navigation and both show zero current documents — the Q90 Series 4 page has 62 archived documents and the Q90-200 Series II page 38, with no status wording — so Boilers.ca records both under one legacy hub with productStatus 'discontinued' and no model-level pages. As with the UB90 lines, the Hydrolevel-type controls use indicator lights rather than discrete fault codes, so no error-code pages are published.
Owners of an installed Q90-050/075/100 (Series 4) or Q90-200 Series II unit can still download the archived spec sheets (419/420) and IOMs from the product pages. The ratings are the US-market figures Dunkirk prints; no Canadian listing was verified on the pages checked on September 9, 2026, so canadianStatus stays 'unknown'. Gas work belongs with a licensed contractor.
Highlights
Models
One canonical page per model with input, output and efficiency kept separate.
Dunkirk Boilers
The Dunkirk Q90-50 is a legacy condensing cast-aluminium gas boiler: 50 MBH input for 45 MBH heating capacity and a 39 MBH net I=B=R rating at 90% AFUE, with a 2" flue arrangement and 220 lb shipping.
Dunkirk Boilers
The Dunkirk Q90-75 is a legacy condensing cast-aluminium gas boiler: 75 MBH input for 68 MBH heating capacity and a 59 MBH net I=B=R rating at 90% AFUE, with a 2" flue arrangement and 220 lb shipping.
Dunkirk Boilers
The Dunkirk Q90-100 is a legacy condensing cast-aluminium gas boiler: 100 MBH input for 90 MBH heating capacity and a 78 MBH net I=B=R rating at 90% AFUE, with a 2" flue arrangement and 220 lb shipping.
Dunkirk Boilers
The Dunkirk Q90-125 is a legacy condensing cast-aluminium gas boiler: 125 MBH input for 112.5 MBH heating capacity and a 98 MBH net I=B=R rating at 90% AFUE, with a 2" CPVC & 3" PVC flue arrangement and 284 lb shipping.
Dunkirk Boilers
The Dunkirk Q90-150 is a legacy condensing cast-aluminium gas boiler: 150 MBH input for 135 MBH heating capacity and a 117 MBH net I=B=R rating at 90% AFUE, with a 2" CPVC & 3" PVC flue arrangement and 284 lb shipping.
Dunkirk Boilers
The Dunkirk Q90-175 is a legacy condensing cast-aluminium gas boiler: 175 MBH input for 157.5 MBH heating capacity and a 137 MBH net I=B=R rating at 90% AFUE, with a 2" CPVC & 3" PVC flue arrangement and 284 lb shipping.
Dunkirk Boilers
The Dunkirk Q90-200 is a legacy condensing cast-aluminium gas boiler: 200 MBH input for 180 MBH heating capacity and a 157 MBH net I=B=R rating at 90% AFUE, with a 2" CPVC & 3" PVC flue arrangement and 284 lb shipping.
| Specification | Dunkirk Q90-50 | Dunkirk Q90-75 | Dunkirk Q90-100 | Dunkirk Q90-125 | Dunkirk Q90-150 | Dunkirk Q90-175 | Dunkirk Q90-200 |
|---|---|---|---|---|---|---|---|
| input-min | — | — | — | — | — | — | — |
| input-max | — | — | — | — | — | — | — |
| output-max | — | — | — | — | — | — | — |
| Efficiency (AFUE) | 90 % | 90 % | 90 % | 90 % | 90 % | 90 % | 90 % |
| turndown | — | — | — | — | — | — | — |
| vent-max-3 | — | — | — | — | — | — | — |
| vent-max-2 | — | — | — | — | — | — | — |
| Package shipping weight | 220 lb | 220 lb | 220 lb | 284 lb | 284 lb | 284 lb | 284 lb |
Read the full comparison: Dunkirk Q90-50 vs Dunkirk Q90-75 →
Read the full comparison: Dunkirk Q90-75 vs Dunkirk Q90-100 →
Read the full comparison: Dunkirk Q90-100 vs Dunkirk Q90-125 →
Read the full comparison: Dunkirk Q90-125 vs Dunkirk Q90-150 →
Error codes and alerts
No alerts documented for this series yet.
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 Dunkirk Boilers boilers
Both Q90 product pages remain live but show zero current documents with all literature archived and no status wording, so Boilers.ca records the Q90 Series 4 and Q90-200 Series II as legacy (productStatus 'discontinued').
Series 4 covers the 50, 75 and 100 MBH sizes on the cast aluminum heat exchanger with a Hydrolevel combination control; Series II covers 125–200 MBH on the cast aluminum monoblock heat exchanger with the Fuel Smart Hydrostat.
Yes — the Q90 pages are Dunkirk's twins of Utica's UB90 Series 4 and UB90-200 Series II lines, at the same 90% AFUE with the same cast aluminum designs; each brand hosts its own pages and archived documents.
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
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.