Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Pennco · Series
The Pennco FSB Series is a cast-iron gas water boiler sold in five sizes from FSB-2 (42.5 MBH input) to FSB-6 (187.5 MBH) at 84–84.4% AFUE, with cast-iron push nipples, a control that delays burner starting until residual heat is transferred, and chimney or sidewall venting options.
Series facts
The ratings table prints 84.4% AFUE on the FSB-2 and 84% on FSB-3 through FSB-6.
The FSB Series is Pennco's gas-fired cast-iron water boiler, published on the official site under Boilers – Gas with the size list '42.5, 75, 112.5, 150, 187.5 MBH'. The sell sheet describes a dependable cast-iron heat exchanger with cast-iron push nipples — the sections and push nipples expand at the same rate when heated, maintaining a water-tight seal over time without gaskets — and a control that monitors water temperature and delays the burner start until residual heat has been transferred, maximizing efficiency by firing only when needed. Optional equipment includes natural gas or propane operation, a Fill-Trol and a thimble; the boiler is design certified for installation on a noncombustible floor and tested for 50 PSI ASME working pressure.
The sell sheet ratings table prints five sizes: FSB-2 (42.5 MBH input, 36 MBH heating capacity, 31 MBH net water rating, 84.4% AFUE, 4" chimney / 3" sidewall, 11" wide, 225 lb), FSB-3 (75/63/55 MBH, 84%, 4"/3", 265 lb), FSB-4 (112.5/95/82 MBH, 84%, 4"/3", 322 lb), FSB-5 (150/127/109 MBH, 84%, 4"/3", 370 lb) and FSB-6 (187.5/158/135 MBH, 84%, 4"/4", 431 lb). Heating capacity and AFUE are based on DOE test procedures and the net water rating uses a 1.15 piping and pickup allowance. All sizes share a 29-inch height and 23-1/4-inch depth, with a 1/2-inch gas inlet and 1-1/4-inch supply and return tappings.
Boilers.ca documents all five sizes at model level from the sell sheet and links the published Series 3 and Series 4 IOMs. No official Canadian-sales statement was found, so canadianStatus stays 'unknown'.
Highlights
Pennco Cast Iron Consolidated Boiler Warranty Rev. C is published on the official documents page.
Models
One canonical page per model with input, output and efficiency kept separate.
Pennco
The Pennco FSB-2 is the smallest FSB size and the only 84.4% AFUE row: 42.5 MBH input with 36 MBH heating capacity and a 31 MBH net water rating at 84.4% AFUE, vented through a 4" chimney or 3" sidewall connection.
Pennco
The Pennco FSB-3 is the second FSB size: 75 MBH input with 63 MBH heating capacity and a 55 MBH net water rating at 84% AFUE, vented through a 4" chimney or 3" sidewall connection.
Pennco
The Pennco FSB-4 is the mid-size FSB: 112.5 MBH input with 95 MBH heating capacity and a 82 MBH net water rating at 84% AFUE, vented through a 4" chimney or 3" sidewall connection.
Pennco
The Pennco FSB-5 is the second-largest FSB size: 150 MBH input with 127 MBH heating capacity and a 109 MBH net water rating at 84% AFUE, vented through a 4" chimney or 3" sidewall connection.
Pennco
The Pennco FSB-6 is the largest FSB size and the only row listing a 4-inch sidewall vent: 187.5 MBH input with 158 MBH heating capacity and a 135 MBH net water rating at 84% AFUE, vented through a 4" chimney or 4" sidewall connection.
| Specification | Pennco FSB-2 | Pennco FSB-3 | Pennco FSB-4 | Pennco FSB-5 | Pennco FSB-6 |
|---|---|---|---|---|---|
| input-min | — | — | — | — | — |
| Input | 42.5 MBH | 75 MBH | 112.5 MBH | 150 MBH | 187.5 MBH |
| output-max | — | — | — | — | — |
| Efficiency (AFUE) | 84.4 % | 84 % | 84 % | 84 % | 84 % |
| turndown | — | — | — | — | — |
| vent-max-3 | — | — | — | — | — |
| vent-max-2 | — | — | — | — | — |
| Approx. shipping weight | 225 lb | 265 lb | 322 lb | 370 lb | 431 lb |
Read the full comparison: Pennco FSB-2 vs FSB-4 →
Read the full comparison: Pennco FSB-2 vs Pennco FSB-3 →
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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 Pennco boilers
Five sizes: FSB-2 through FSB-6, covering 42.5, 75, 112.5, 150 and 187.5 MBH input at 84.4% (FSB-2) or 84% AFUE per the sell sheet.
The ratings table lists a 4-inch chimney connection for all sizes and a 3-inch sidewall option except the FSB-6, which lists 4-inch sidewall; a thimble is an optional accessory and the IOM covers approved venting materials.
The sell sheet highlights cast-iron push nipples — sections and push nipples expand at the same rate, maintaining a water-tight seal without gaskets — and a control that delays the burner start until residual heat has been transferred.
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.