Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The ClearFire-C 2500 adds 700,000 BTU/hr of input and 672,000 BTU/hr of output over the ClearFire-C 1800. The CFC 2500 adds 700,000 BTU/hr of input over the 1800, moving to 5 in flanged water connections, 126 gal water content and a 12 in flue shared with the 1800.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Cleaver-Brooks ClearFire-C 1800 | Cleaver-Brooks ClearFire-C 2500 |
|---|---|---|
| Input (max) | 1,800,000 BTU/hr | 2,500,000 BTU/hr |
| Output at 104/86°F, 100% firing | 1,728,000 BTU/hr | 2,400,000 BTU/hr |
| Boiler horsepower | 51.6 | 71.7 |
| Efficiency (page) | 99 % | 99 % |
| Water content | 99 gal | 126 gal |
| Shipping weight | 2,505 lb | 3,640 lb |
| Water supply / return | 4" 150# RF flanged | 5" 150# RF flanged |
| Flue gas connection | 12 in | 12 in |
The CFC 1800 carries 99% efficiency and the CFC 2500 99%. The ClearFire-C 2500 adds 700,000 BTU/hr of input and 672,000 BTU/hr of output over the ClearFire-C 1800. The CFC 2500 adds 700,000 BTU/hr of input over the 1800, moving to 5 in flanged water connections, 126 gal water content and a 12 in flue shared with the 1800.
Water content moves from 99 gal to 126 gal, which changes the system volume and buffer behaviour. Shipping weight steps from 2,505 lb to 3,640 lb, so rigging and floor loading should be checked against the larger unit. Pressure rating: 125 on the smaller unit against 125 on the larger.
Both models are documented in the same official Cleaver-Brooks material, so the choice is a load and plant-layout decision: size to the calculated demand, then verify connections, venting and weight in the family document for the exact model.
Cleaver-Brooks
The Cleaver-Brooks ClearFire-C 1800 (Model CFC 1800) is a fully condensing hydronic boiler rated 1,800,000 BTU/hr input and 1,728,000 BTU/hr output at 104/86°F, with 51.6 BHP and 99 gal water content per the official CB-8278 Dimensions and Ratings.
Cleaver-Brooks
The Cleaver-Brooks ClearFire-C 2500 (Model CFC 2500) is a fully condensing hydronic boiler rated 2,500,000 BTU/hr input and 2,400,000 BTU/hr output at 104/86°F, with 71.7 BHP and 126 gal water content per the official CB-8278 Dimensions and Ratings.
5 in 150# flanged water supply/return, a 1-1/2 in gas connection, a 12 in flue and 8 in combustion air per CB-8278.
99 gal for the CFC 1800 and 126 gal for the CFC 2500, per CB-8278.
A consultation includes a heat-loss review so the size is right the first time.
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.