Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The ClearFire-C 750 adds 250,000 BTU/hr of input and 240,000 BTU/hr of output over the ClearFire-C 500. The CFC 500 and 750 share the same cabinet, 51 gal water content and 1,160 lb shipping weight, so the 250,000 BTU/hr step needs no physical change; both hold a 6 in flue and 2-1/2 in flanged water connections.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Cleaver-Brooks ClearFire-C 500 | Cleaver-Brooks ClearFire-C 750 |
|---|---|---|
| Input (max) | 500,000 BTU/hr | 750,000 BTU/hr |
| Output at 104/86°F, 100% firing | 480,000 BTU/hr | 720,000 BTU/hr |
| Boiler horsepower | 14.3 | 21.5 |
| Efficiency (page) | 99 % | 99 % |
| Water content | 51 gal | 51 gal |
| Shipping weight | 1,160 lb | 1,160 lb |
| Water supply / return | 2-1/2" 150# RF flanged | 2-1/2" 150# RF flanged |
| Flue gas connection | 6 in | 6 in |
The CFC 500 carries 99% efficiency and the CFC 750 99%. The ClearFire-C 750 adds 250,000 BTU/hr of input and 240,000 BTU/hr of output over the ClearFire-C 500. The CFC 500 and 750 share the same cabinet, 51 gal water content and 1,160 lb shipping weight, so the 250,000 BTU/hr step needs no physical change; both hold a 6 in flue and 2-1/2 in flanged water connections.
Water content moves from 51 gal to 51 gal, which changes the system volume and buffer behaviour. Shipping weight steps from 1,160 lb to 1,160 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 500 (Model CFC 500) is a fully condensing hydronic boiler rated 500,000 BTU/hr input and 480,000 BTU/hr output at 104/86°F, with 14.3 BHP and 51 gal water content per the official CB-8278 Dimensions and Ratings.
Cleaver-Brooks
The Cleaver-Brooks ClearFire-C 750 (Model CFC 750) is a fully condensing hydronic boiler rated 750,000 BTU/hr input and 720,000 BTU/hr output at 104/86°F, with 21.5 BHP and 51 gal water content per the official CB-8278 Dimensions and Ratings.
Yes — CB-8278 prints the same dimensions, 51 gal water content, 1,160 lb shipping weight and 2-1/2 in flanged water connections for both.
480,000 BTU/hr for the CFC 500 and 720,000 BTU/hr for the CFC 750 at 104/86°F, 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.