Commercial Boilers
ENERGY STAR certified commercial boilers, with thermal efficiency, full-load input rate and turndown ratio.
386 models · 31 brands
- Best
- 98.7%
- Median
- 96.5%
- Worst
- 94%
Thermal Eff across 386 models that report it.
Commercial boilers are rated by thermal efficiency and combustion efficiency. Thermal efficiency measures useful heat output as a percentage of fuel input; combustion efficiency measures how completely the fuel burns. Condensing commercial boilers achieve thermal efficiencies above 95% and are required by many energy codes for new construction.
Capacity is measured in MBH (thousand BTU per hour). Commercial installations often use multiple smaller boilers rather than one large unit, so the system can stage capacity to match the load — running one boiler at full efficiency rather than two at half capacity.
Most efficient
Ranked by thermal eff, an efficiency ratio that does not scale with size.
| Model | Brand | Input | Thermal Eff |
|---|---|---|---|
| HTH 01751 A | Hamilton Engineering | 1750MBTU/hr | 98.7% |
| HTH 01751 AX | Hamilton Engineering | 1750MBTU/hr | 98.7% |
| WB1751 | RBI WATER HEATERS | 1750MBTU/hr | 98.7% |
| WB1751X | RBI WATER HEATERS | 1750MBTU/hr | 98.7% |
| HTH 01251 A | Hamilton Engineering | 1250MBTU/hr | 98.4% |
| HTH 02001 A | Hamilton Engineering | 1999MBTU/hr | 98.4% |
| WB1251 | RBI WATER HEATERS | 1250MBTU/hr | 98.4% |
| WB2001 | RBI WATER HEATERS | 1999MBTU/hr | 98.4% |