Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
Boilers.ca is a brand of ROMA Heating & Cooling · Licensed gas contractor LGA0202903
Comparison
Verdict in brief
The DCB-75 and DCB-100 are the two smallest DCB heating-only boilers of the discontinued '(While supplies last)' AI line. They share the shallow 13-9/16" cabinet at 94 lb and near-identical 16.6 MBH minimum fires; the DCB-100 raises the input ceiling from 75 to 93.5 MBH with heating capacity up from 68.2 to 85.4 MBH — and the DCB-75 is the only model of the family that prints 92% AFUE rather than 95%.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Dunkirk DCB-75 | Dunkirk DCB-100 |
|---|---|---|
| Central-heating input, minimum | 16.6 MBH | 16.6 MBH |
| Central-heating input, maximum | 75 MBH | 93.5 MBH |
| AFUE | 92 % | 95 % |
| Heating capacity | 68.2 MBH | 85.4 MBH |
| Net water rating | 60 MBH | 74 MBH |
| Turndown, heating mode | 4.5:1 | 5.6:1 |
| Dimensions (H x W x D) | 30" x 17-3/4" x 13-9/16" | 30" x 17-3/4" x 13-9/16" |
| Weight | 94 lb | 94 lb |
Both are wall-hung, heating-only models of the DCC/DCB AI condensing family in the 30" x 17-3/4" cabinet at 13-9/16" depth and 94 lb, with 1 gallon water content, 3/4" system supply/return (G straight thread), 3/4" NPT gas and 13/16" ID-hose condensate.
The sell sheet prints CH input of 16.6-75 MBH on the DCB-75 against 16.6-93.5 MBH on the DCB-100, with heating capacity of 68.2 versus 85.4 MBH and net water ratings of 60 versus 74 MBH. The DCB-75's 92% AFUE is printed as-is in the official table while every sibling prints 95%.
With identical minimum fires, the pair modulates the same in mild weather; the DCB-100 only earns its place where the design-day load exceeds the 75's 68.2 MBH of capacity. Both sit on a page printing '(While supplies last)' with zero current documents, so guidance here is for service of installed units rather than new purchases.
Dunkirk Boilers
The Dunkirk DCB-75 is the 75 MBH-class central-heating model of the DCB 'AI' condensing line: 16.6 to 75 MBH input at 92% AFUE with 68.2 MBH heating capacity and a 60 MBH net water rating. The DCB page prints '(While supplies last)' with no current documents, so this model is discontinued (sell-through).
Dunkirk Boilers
The Dunkirk DCB-100 is the 93.5 MBH-class central-heating model of the DCB 'AI' condensing line: 16.6 to 93.5 MBH input at 95% AFUE with 85.4 MBH heating capacity and a 74 MBH net water rating. The DCB page prints '(While supplies last)' with no current documents, so this model is discontinued (sell-through).
As printed in the official sell sheet table: the DCB-75 lists 92% AFUE while the DCB-100 and the rest of the family list 95% — the same anomaly appears on Utica's MAH-75 twin.
Effectively — both use the shallow 13-9/16" cabinet at 94 lb with 16.6 MBH minimum fires; only the input ceiling and capacity differ.
The official DCB page prints '(While supplies last)' with no current documents — the line is in end-of-life sell-through, so availability is limited to remaining dealer stock.
A consultation includes a heat-loss review so the size is right the first time.
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.