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
Dunkirk Boilers · Series
The Dunkirk WPSB Series 4 is the current atmospheric cast-iron gas water boiler line: seven natural-gas sizes from WPSB-3D (75 MBH) to WPSB-9D (299 MBH), net AHRI water ratings of 55 to 218 MBH, up to 84.1% AFUE and a Fuel Smart Hydrostat control with limit, low-water cut-off and boiler reset in an integral-draft-hood, vent-damper package.
Series facts
Up to 84.1% AFUE per the Series 4 brochure ratings table (WPSB-5D and WPSB-6D at 84.1%; the remaining sizes print 84.0%).
The WPSB Series 4 is documented on Dunkirk's current gas-boiler page (slug gas-boiler-wpsb-2) as an atmospheric cast-iron boiler with an integral draft hood and automatic vent damper that reduce overall height for low-clearance installations. The product page lists natural-gas (D) sizes at 75, 112.5, 150, 187.5, 225, 262 and 299 MBH and propane (DP) sizes at 70, 105, 140, 175, 210, 245 and 280 MBH.
The Series 4 brochure's AHRI-certified ratings table prints the seven natural-gas rows: WPSB-3D (75 MBH input / 63 heating capacity / 55 net water / 84.0% AFUE), WPSB-4D (112.5 / 94 / 82 / 84.0%), WPSB-5D (150 / 126 / 110 / 84.1%), WPSB-6D (187.5 / 157 / 137 / 84.1%), WPSB-7D (225 / 188 / 163 / 84.0%), WPSB-8D (262 / 221 / 191 / 84.0%) and WPSB-9D (299 / 252 / 218 / 84.0%), with water content from 6.3 to 17.2 gallons and shipping weights of 315 to 750 lb. All models connect on 1-1/4 in. water return/supply with a 1/2 in. NPT gas inlet and run on 120 V AC at less than 12 A.
The control module is the Fuel Smart Hydrostat (temperature limit, low-water cut-off and boiler reset with circulator relay and domestic-hot-water input override), with a temperature LED display and diagnostic indicator lights. Boilers.ca records the series and its seven printed sizes; no official Canadian-sales statement was found, so canadianStatus stays 'unknown', and gas, combustion and venting work belongs with a licensed contractor against the WPSB manual Rev. F.
Highlights
Models
One canonical page per model with input, output and efficiency kept separate.
Dunkirk Boilers
The Dunkirk WPSB-3D is a current atmospheric cast-iron gas water boiler: 75 MBH natural-gas input (propane 70 MBH) for 63 MBH heating capacity and a 55 MBH net AHRI water rating at 84% AFUE, with 6.3 gallons of water content and a Fuel Smart Hydrostat control.
Dunkirk Boilers
The Dunkirk WPSB-4D is a current atmospheric cast-iron gas water boiler: 112.5 MBH natural-gas input (propane 105 MBH) for 94 MBH heating capacity and a 82 MBH net AHRI water rating at 84% AFUE, with 8.1 gallons of water content and a Fuel Smart Hydrostat control.
Dunkirk Boilers
The Dunkirk WPSB-5D is a current atmospheric cast-iron gas water boiler: 150 MBH natural-gas input (propane 140 MBH) for 126 MBH heating capacity and a 110 MBH net AHRI water rating at 84.1% AFUE, with 9.9 gallons of water content and a Fuel Smart Hydrostat control.
Dunkirk Boilers
The Dunkirk WPSB-6D is a current atmospheric cast-iron gas water boiler: 187.5 MBH natural-gas input (propane 175 MBH) for 157 MBH heating capacity and a 137 MBH net AHRI water rating at 84.1% AFUE, with 11.7 gallons of water content and a Fuel Smart Hydrostat control.
Dunkirk Boilers
The Dunkirk WPSB-7D is a current atmospheric cast-iron gas water boiler: 225 MBH natural-gas input (propane 210 MBH) for 188 MBH heating capacity and a 163 MBH net AHRI water rating at 84% AFUE, with 13.5 gallons of water content and a Fuel Smart Hydrostat control.
Dunkirk Boilers
The Dunkirk WPSB-8D is a current atmospheric cast-iron gas water boiler: 262 MBH natural-gas input (propane 245 MBH) for 221 MBH heating capacity and a 191 MBH net AHRI water rating at 84% AFUE, with 15.3 gallons of water content and a Fuel Smart Hydrostat control.
Dunkirk Boilers
The Dunkirk WPSB-9D is a current atmospheric cast-iron gas water boiler: 299 MBH natural-gas input (propane 280 MBH) for 252 MBH heating capacity and a 218 MBH net AHRI water rating at 84% AFUE, with 17.2 gallons of water content and a Fuel Smart Hydrostat control.
| Specification | Dunkirk WPSB-3D | Dunkirk WPSB-4D | Dunkirk WPSB-5D | Dunkirk WPSB-6D | Dunkirk WPSB-7D | Dunkirk WPSB-8D | Dunkirk WPSB-9D |
|---|---|---|---|---|---|---|---|
| input-min | — | — | — | — | — | — | — |
| input-max | — | — | — | — | — | — | — |
| output-max | — | — | — | — | — | — | — |
| Efficiency (AFUE) | 84 % | 84 % | 84.1 % | 84.1 % | 84 % | 84 % | 84 % |
| turndown | — | — | — | — | — | — | — |
| vent-max-3 | — | — | — | — | — | — | — |
| vent-max-2 | — | — | — | — | — | — | — |
| Shipping weight | 315 lb | 377 lb | 453 lb | 534 lb | 601 lb | 665 lb | 750 lb |
Read the full comparison: Dunkirk WPSB-3D vs Dunkirk WPSB-4D →
Read the full comparison: Dunkirk WPSB-4D vs Dunkirk WPSB-5D →
Read the full comparison: Dunkirk WPSB-5D vs Dunkirk WPSB-6D →
Read the full comparison: Dunkirk WPSB-6D vs Dunkirk WPSB-7D →
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
Seven natural-gas sizes — WPSB-3D through WPSB-9D at 75, 112.5, 150, 187.5, 225, 262 and 299 MBH — with propane (DP) versions listed at 70, 105, 140, 175, 210, 245 and 280 MBH on the product page.
The Series 4 brochure ratings table prints 84.0–84.1% AFUE, with the WPSB-5D and WPSB-6D rows at the line's 84.1% top figure.
No — it is an atmospheric cast-iron boiler with an integral draft hood, automatic vent damper and chimney venting; the AFUE rows print in the 84% class.
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.