Dunkirk Boilers · Q90 (Series 4 and Q90-200 Series II)
Dunkirk Q90-125
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.
Key figures
- Max input
- —
- Max CSA output
- —
- AFUE
- 90 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Dunkirk Q90-125 in practice
The Q90-125 is one of the four Q90-200 Series II sizes (125, 150, 175 and 200 MBH) in Dunkirk's legacy condensing line. Its spec sheet ratings row prints 125 MBH input, 112.5 MBH heating capacity and a 98 MBH net I=B=R rating (1.15 allowance) at 90% AFUE, with a 2" CPVC & 3" PVC flue arrangement and 284 lb package shipping weight.
The Q90-200 Series II uses a cast aluminium monoblock heat exchanger, the Fuel Smart Hydrostat (temperature limit, LWCO and boiler reset in one control) and CPVC/PVC venting, with 3 in. pipe runs of 6 ft minimum to 60 ft maximum plus four 90-degree elbows. Both spec sheets print a 15-year limited heat exchanger warranty, and the boilers run on natural or propane gas.
Neither Q90 page appears in Dunkirk's current category navigation and both show zero current documents (62 and 38 archived respectively), so Boilers.ca records the models as discontinued for identification and service planning. No official Canadian-sales statement was found, so canadianStatus stays 'unknown'; gas and combustion work belongs with a licensed contractor against the archived IOM for the specific series.
Best suited to
- Owners documenting an installed Q90-125 against the official spec sheet
- Service planning for the Q90-200 Fuel Smart Hydrostat platform
- Legacy replacement research in the 90% AFUE condensing class
Applicability and support
- Model number
- Q90-125
- Canadian availability
- unknown
- 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 Dunkirk Boilers. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input | 125 MBH | Input per the official spec sheet ratings table (sea level through 2,000 ft). |
| Output | ||
| Heating capacity | 112.5 MBH | Heating capacity per the official spec sheet (DOE test procedures). |
| Net I=B=R rating | 98 MBH | Net I=B=R rating based on an allowance of 1.15 per the spec sheet. |
| Efficiency | ||
| Efficiency (AFUE) | 90 % | 90% AFUE per the spec sheet and both Q90 product pages; the lines are ENERGY STAR rated. |
| Domestic hot water | ||
| Domestic hot water | Heating-only boiler — domestic hot water comes from a separate indirect tank or water heater | |
| Venting and air | ||
| Flue | 2" CPVC & 3" PVC | Flue arrangement per the Q90-200 Series II spec sheet; 3 in. pipe runs 6 ft minimum to 60 ft maximum plus four 90-degree elbows. |
| Physical and connections | ||
| Package shipping weight | 284 lb | Shipping weight per the spec sheet. |
| Connections | Gas 1/2 in. IPS; supply & return 1-1/4 in. NPT | Per the Q90-200 Series II spec sheet. |
| Heat exchanger | Cast aluminium monoblock | Per the official spec sheets; the lines are the Dunkirk twins of the Utica UB90 family. |
| Operating limits and other | ||
| Warranty | 15-year limited heat exchanger warranty | As printed on both spec sheets. |
Manuals
- Q90-200 Spec Sheet Rev. 1.0 (PN 240005688, 10/05)240005688 Rev. 1.0 · 2005-10
- Q90-200 Series II IOM Rev. C (3196)3196 Rev. C
Alerts documented for this model
None documented yet.
Frequently asked questions
What are the Q90-125's ratings?
125 MBH input, 112.5 MBH heating capacity and a 98 MBH net I=B=R rating at 90% AFUE per the official spec sheet.
Is the Q90-125 still sold?
No — neither Q90 page shows current documents (all literature is archived), so Boilers.ca records the line as discontinued.
What heat exchanger does the Q90-125 use?
A cast aluminium monoblock heat exchanger per the Q90-200 Series II spec sheet.
Questions about the Dunkirk Q90-125?
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.
Compare and explore
- Dunkirk Q90-100 vs Dunkirk Q90-125Comparison
- Dunkirk Q90-125 vs Dunkirk Q90-150Comparison
- Dunkirk Q90-50Same series
- Dunkirk Q90-75Same series
- Dunkirk Q90-100Same series
- Dunkirk Q90-150Same series
- Dunkirk Q90-175Same series
- Dunkirk Q90-200Same series
- Q90 (Series 4 and Q90-200 Series II) series hub
- Buying guide
Sources and verification
- Dunkirk — Q90-200 Series II product page (0 current documents) · accessed September 9, 2026
- Dunkirk — Q90-200 Spec Sheet Rev. 1.0 (archived) · accessed September 9, 2026
- Dunkirk — Q90-200 Series II IOM Rev. C (archived) · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.