Burnham ES2 ES28
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.
Key figures
- Max input
- 245 MBH
- Max CSA output
- —
- AFUE
- 85 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Burnham ES2 ES28 in practice
The ES28 is the second-largest ES2 at a fixed 245 MBH input, printing 208 MBH DOE heating capacity and a 181 MBH net AHRI water rating at 85% AFUE (ES2 I&O ratings table, Doc 103780-11). It shares the 7" natural-draft draft hood with the ES27 and is a NON-condensing cast-iron boiler vented Category I into an existing lined chimney.
The ES28 ships at 518 lb (438 lb empty) with 1-1/4" NPT supply/return and 3/4" NPT gas connections, on the IQ Boiler Control System with optional outdoor-reset and LWCO cards, natural or LP gas. MAWP is 50 psi with a 30 psi shipped relief valve; supply water runs 130–220°F with a 110°F minimum return. Family dimensions reach 35" deep by 27-3/4" wide by 41" high on this size. Sizing and installation are licensed-contractor work from a heat-loss calculation.
Best suited to
- Large homes and light-commercial loads near a fixed 245 MBH input
- Chimney replacements where a 7" draft-hood connector matches the existing flue
- Owners wanting maximum cast-iron capacity before the top ES29 size
Applicability and support
- Model number
- ES28
- Canadian availability
- unknown
- Production status
- current
- ROMA supplies
- Confirmed at consultation
- ROMA services
- Confirmed at consultation
- Warranty
- Series terms
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.
Specifications
Published specifications
Values as published by Burnham. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input | 245 MBH | Fixed input (no modulation) per the ES2 ratings table (Doc 103780-11); ratings apply to elevations up to 2,000 ft. |
| Output | ||
| DOE heating capacity | 208 MBH | Per the ES2 ratings table. |
| Net AHRI water rating | 181 MBH | Net AHRI water rating based on a piping and pickup allowance of 1.15, per the ES2 ratings table. |
| Efficiency | ||
| Efficiency (AFUE) | 85 % | 85% AFUE — a NON-condensing rating; the ES2 is a natural-draft cast-iron boiler, not a condensing design. |
| Domestic hot water | ||
| Domestic hot water | Heating-only boiler — domestic hot water comes from a separate indirect tank or water heater | |
| Venting and air | ||
| Venting | Category I natural draft — draft hood into an existing lined chimney (Type B/L gas vent); 7" draft hood | Non-condensing, natural-draft design: NOT a direct-vent or condensing boiler. Draft hood sizes per the ES2 I&O manual specifications. |
| Physical and connections | ||
| Shipping weight | 518 lb | Shipping weight 518 lb; empty (uncrated) boiler weight 438 lb, per the ES2 I&O manual weights and volume table. |
| Supply/return connections | 1-1/4" NPT | Supply and return both 1-1/4" NPT; relief valve 3/4" and drain 3/4" per the ES2 I&O manual. |
| Gas connection | 3/4" NPT | 3/4" NPT gas connection (ES27–ES29); ES23–ES26 use 1/2" NPT. |
| Electrical | ||
| Electrical | 120 VAC, 60 Hz, 1-phase, 15 A | Per the ES2 I&O manual specifications. |
| Operating limits and other | ||
| Maximum allowable working pressure (MAWP) | 50 psi | 50 psi MAWP; the boiler ships from the factory with a 30 psi safety relief valve. |
| Control | IQ Boiler Control System | IQ control with optional outdoor-reset and LWCO IQ option cards; the control flashes 'Err' + number for faults. |
Frequently asked questions
What are the ES28's ratings?
245 MBH fixed input, 208 MBH DOE heating capacity, a 181 MBH net AHRI water rating and 85% AFUE per the ES2 ratings table.
What are the ES28's dimensions?
The ES28 measures 35" deep, 27-3/4" wide and 41" high per the ES2 I&O manual dimensions and connections table.
Is the ES28 the largest ES2?
No — the ES29 is larger at 280 MBH input; the ES28 is the second-largest size.
Questions about the Burnham ES2 ES28?
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
- U.S. Boiler Company — ES2 High Efficiency Gas-Fired Water Boiler product page · accessed September 8, 2026
- U.S. Boiler Company — Technical Literature (Alpine/ES2 I&O manual listings) · accessed September 8, 2026
- ES2 Gas Boiler — Installation, Operating & Service Instructions, Doc 103780-11 (PDF) · 103780-11 · accessed September 8, 2026
Facts checked September 8, 2026. Last updated September 8, 2026. Technical reviewer: not yet assigned.