Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Peerless Boilers · Series
The Series MI is Peerless' legacy residential cast-iron gas hot water boiler — seven fixed-input sizes MI-03 through MI-09 from 70 to 260 MBH input and 58 to 211 MBH output at 82.0–82.2% AFUE, natural-draft chimney venting with a front-facing integral draft diverter. The official site groups the line under 'Out of Circulation'.
Series facts
The in-page ratings table prints 82.2% AFUE on the MI-03 and 82.0–82.1% on MI-04 through MI-09.
The Series MI is Peerless' legacy residential cast-iron hot water boiler, published on the official site under the 'Out of Circulation – Gas Boilers' section. The product page describes a fully packaged, ready-to-install boiler for conventional chimney applications whose heat exchanger 'features a greater percentage of cast iron than the competition for a long life of durability and dependability', with a front-facing integral draft diverter for a low-profile installation in tight spaces with low ceilings, and a non-prorated lifetime warranty on the heat exchanger.
The in-page ratings table covers seven fixed-input sizes — MI-03 (70 MBH input, 58 MBH heating capacity, 50 MBH net water rating, 82.2% AFUE), MI-04 (105/86/75, 82.1%), MI-05 (140/115/100, 82.0%), MI-06 (175/143/124, 82.0%), MI-07 (195/160/139, 82.0%), MI-08 (227.5/186/162, 82.0%) and MI-09 (260/211/183, 82.0%) — with net water ratings based on a piping and pickup allowance of 1.15 and boiler water content of 4.72–12.40 US gallons. The dimensions table prints jacket length 26-5/8" (MI-03 through MI-07) or 29-5/8" (MI-08/MI-09), widths of 12-1/2"–32-3/4", a 31-3/8" jacket height and 5"–8" vent diameters.
The official site groups the Series MI under 'Out of Circulation', so Boilers.ca records productStatus 'discontinued' and documents all seven sizes at model level from the product page and the MI8038 R19 I&O manual. No official Canadian-sales statement was found — research reviewed US-site data only — so canadianStatus stays 'unknown', and gas, combustion and venting work belongs with a licensed contractor.
Highlights
Models
One canonical page per model with input, output and efficiency kept separate.
Peerless Boilers
The Peerless Series MI MI-03 is the smallest Series MI size of the legacy cast-iron gas water line: 70 MBH fixed input for 58 MBH heating capacity and a 50 MBH net water rating at 82.2% AFUE, with 4.72 US gallons of boiler water content, on the natural-draft chimney platform.
Peerless Boilers
The Peerless Series MI MI-04 is a 105 MBH mid-small size of the legacy cast-iron gas water line: 105 MBH fixed input for 86 MBH heating capacity and a 75 MBH net water rating at 82.1% AFUE, with 6 US gallons of boiler water content, on the natural-draft chimney platform.
Peerless Boilers
The Peerless Series MI MI-05 is a 140 MBH mid size of the legacy cast-iron gas water line: 140 MBH fixed input for 115 MBH heating capacity and a 100 MBH net water rating at 82% AFUE, with 7.28 US gallons of boiler water content, on the natural-draft chimney platform.
Peerless Boilers
The Peerless Series MI MI-06 is a 175 MBH mid-large size of the legacy cast-iron gas water line: 175 MBH fixed input for 143 MBH heating capacity and a 124 MBH net water rating at 82% AFUE, with 8.56 US gallons of boiler water content, on the natural-draft chimney platform.
Peerless Boilers
The Peerless Series MI MI-07 is a 195 MBH large size of the legacy cast-iron gas water line: 195 MBH fixed input for 160 MBH heating capacity and a 139 MBH net water rating at 82% AFUE, with 9.84 US gallons of boiler water content, on the natural-draft chimney platform.
Peerless Boilers
The Peerless Series MI MI-08 is a 227.5 MBH large size of the legacy cast-iron gas water line: 227.5 MBH fixed input for 186 MBH heating capacity and a 162 MBH net water rating at 82% AFUE, with 11.12 US gallons of boiler water content, on the natural-draft chimney platform.
Peerless Boilers
The Peerless Series MI MI-09 is the largest Series MI size of the legacy cast-iron gas water line: 260 MBH fixed input for 211 MBH heating capacity and a 183 MBH net water rating at 82% AFUE, with 12.4 US gallons of boiler water content, on the natural-draft chimney platform.
| Specification | Peerless Series MI MI-03 | Peerless Series MI MI-04 | Peerless Series MI MI-05 | Peerless Series MI MI-06 | Peerless Series MI MI-07 | Peerless Series MI MI-08 | Peerless Series MI MI-09 |
|---|---|---|---|---|---|---|---|
| input-min | — | — | — | — | — | — | — |
| input-max | — | — | — | — | — | — | — |
| output-max | — | — | — | — | — | — | — |
| Efficiency (AFUE) | 82.2 % | 82.1 % | 82 % | 82 % | 82 % | 82 % | 82 % |
| turndown | — | — | — | — | — | — | — |
| vent-max-3 | — | — | — | — | — | — | — |
| vent-max-2 | — | — | — | — | — | — | — |
| weight | — | — | — | — | — | — | — |
Read the full comparison: Peerless Series MI MI-03 vs MI-04 →
Read the full comparison: Peerless Series MI MI-04 vs MI-05 →
Read the full comparison: Peerless Series MI MI-05 vs MI-06 →
Read the full comparison: Peerless Series MI MI-06 vs MI-07 →
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 Peerless Boilers boilers
No — the official site groups the Series MI under 'Out of Circulation' (verified September 9, 2026), so Boilers.ca records productStatus 'discontinued'. The product page and I&O manual remain published for owners of installed units.
Seven fixed-input sizes: MI-03 through MI-09 at 70, 105, 140, 175, 195, 227.5 and 260 MBH input, with 58–211 MBH heating capacities, 50–183 MBH net water ratings and 82.0–82.2% AFUE per the in-page ratings table.
Yes — it is a natural-draft boiler for conventional chimney applications with a front-facing integral draft diverter; it is not a direct-vent or condensing design.
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.