Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Burnham · Series
The ES2 ('Efficiency Series 2') is Burnham's current mid-efficiency cast-iron gas water boiler from U.S. Boiler Company: fixed-input ES23–ES29 models from 70 to 280 MBH input at 85% AFUE, a NON-condensing Category I natural-draft design with draft hood that U.S. Boiler positions as a chimney-replacement boiler.
Series facts
85% AFUE per the ES2 I&O ratings table (Doc 103780-11) and the official product page — a non-condensing, natural-draft design, not a condensing boiler.
The ES2 is the current mid-efficiency cast-iron gas boiler line of the Burnham brand, built and documented by U.S. Boiler Company. It is NOT condensing: at 85% AFUE the ES2 is a natural-draft boiler with a draft hood, vented as Category I into an existing lined chimney (Type B/L gas vent), and the official product page positions it as an optimal replacement boiler for homes with existing chimneys. Seven fixed-input models — ES23 through ES29 — span 70 to 280 MBH input with DOE heating capacities of 59 to 238 MBH, per the ratings table in the ES2 I&O manual (Doc 103780-11, 4/25).
The line runs the IQ Boiler Control System with optional outdoor-reset and low-water cut-off option cards, accepts natural or LP gas, ships at 50 psi MAWP with a 30 psi relief valve, and connects with 1-1/4" NPT supply and return. U.S. Boiler's product page describes the cast-iron heat exchanger with a well-insulated heavy-duty steel base and 'industry standard tapping locations', backed by a lifetime limited warranty. ES2 dimensions run 33–35" deep by 12-3/4"–30-3/4" wide by 41" high across the 2–9-section build range, and ratings apply to 2,000 ft elevation with high-altitude guidance in the manual's Appendix G.
U.S. Boiler publishes the ES2 I&O manual publicly on its Technical Literature page, which Boilers.ca links here. The same literature page also lists other Series-named gas boiler documents (Series 2, Series 2e, Series 3 and others) — the ES2 is a separate family from those lines, and Boilers.ca documents the ES2 at model level (ES23–ES29) only. No official Canadian-sales statement was found, so canadianStatus stays 'unknown'; cast-iron Burnham units of these generations are nevertheless common in Canadian mechanical rooms. All gas, combustion and venting work belongs with a licensed contractor.
Highlights
Lifetime limited warranty, per the official ES2 product page (cast-iron heat exchanger construction).
Models
One canonical page per model with input, output and efficiency kept separate.
Burnham
The Burnham ES2 ES23 is the entry size of the ES2 cast-iron line: a fixed 70 MBH input for 59 MBH DOE heating capacity and a 51 MBH net AHRI rating at 85% AFUE — a non-condensing, Category I draft-hood boiler designed to replace a boiler in an existing chimney.
Burnham
The Burnham ES2 ES24 steps the cast-iron ES2 line to a fixed 105 MBH input: 89 MBH DOE heating capacity and a 77 MBH net AHRI rating at 85% AFUE, with a 5" draft hood for Category I chimney venting.
Burnham
The Burnham ES2 ES25 fires a fixed 140 MBH input for 119 MBH DOE heating capacity and a 103 MBH net AHRI rating at 85% AFUE — the first 6" draft-hood size of the non-condensing, Category I ES2 cast-iron line.
Burnham
The Burnham ES2 ES26 fires a fixed 175 MBH input for 149 MBH DOE heating capacity and a 130 MBH net AHRI rating at 85% AFUE, sharing the 6" draft hood with the ES25 in the non-condensing Category I ES2 line.
Burnham
The Burnham ES2 ES27 fires a fixed 210 MBH input for 178 MBH DOE heating capacity and a 155 MBH net AHRI rating at 85% AFUE, stepping to a 7" draft hood and 3/4" NPT gas in the non-condensing Category I ES2 cast-iron line.
Burnham
The Burnham ES2 ES28 fires a fixed 245 MBH input for 208 MBH DOE heating capacity and a 181 MBH net AHRI rating at 85% AFUE, with a 7" draft hood and 3/4" NPT gas — the second-largest non-condensing ES2 cast-iron size.
Burnham
The Burnham ES2 ES29 tops the ES2 cast-iron line at a fixed 280 MBH input: 238 MBH DOE heating capacity and a 207 MBH net AHRI rating at 85% AFUE, with the line's largest 8" draft hood for Category I chimney venting.
| Specification | Burnham ES2 ES23 | Burnham ES2 ES24 | Burnham ES2 ES25 | Burnham ES2 ES26 | Burnham ES2 ES27 | Burnham ES2 ES28 | Burnham ES2 ES29 |
|---|---|---|---|---|---|---|---|
| input-min | — | — | — | — | — | — | — |
| Input | 70 MBH | 105 MBH | 140 MBH | 175 MBH | 210 MBH | 245 MBH | 280 MBH |
| output-max | — | — | — | — | — | — | — |
| Efficiency (AFUE) | 85 % | 85 % | 85 % | 85 % | 85 % | 85 % | 85 % |
| turndown | — | — | — | — | — | — | — |
| vent-max-3 | — | — | — | — | — | — | — |
| vent-max-2 | — | — | — | — | — | — | — |
| Shipping weight | 254 lb | 304 lb | 357 lb | 405 lb | 462 lb | 518 lb | 564 lb |
Read the full comparison: Burnham ES2 ES23 vs ES24 →
Read the full comparison: Burnham ES2 ES24 vs ES25 →
Read the full comparison: Burnham ES2 ES25 vs ES26 →
Read the full comparison: Burnham ES2 ES26 vs ES27 →
Error codes and alerts
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 Burnham boilers
No. The ES2 is a non-condensing cast-iron boiler at 85% AFUE with a natural-draft draft hood and Category I venting into an existing chimney (Type B/L gas vent). It is a mid-efficiency chimney-replacement design, not a direct-vent condensing boiler.
Yes — the ES2 remains of current US manufacture, with its I&O manual (Doc 103780-11, 4/25) on U.S. Boiler Company's Technical Literature page and a current product page listing a lifetime limited warranty. No official Canadian-sales statement was found.
The ES2 at model level (ES23–ES29) on this hub. The Alpine condensing line is documented separately. Other Series-named products in U.S. Boiler's literature (Series 2, Series 2e, Series 3) are separate families that Boilers.ca does not model on this page.
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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 8, 2026. Last updated September 8, 2026. Technical reviewer: not yet assigned.