Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
Crown Cayman CWI103 and Crown Cayman CWI138 are two non-condensing boilers from the Crown Boiler Co. Cayman (legacy) line. Published ratings: Crown Cayman CWI103 at 103 MBH input, 86 MBH heating capacity and 83.1% AFUE; Crown Cayman CWI138 at 138 MBH input, 115 MBH heating capacity and 83.1% AFUE. Crown Cayman CWI138 lists 35 MBH more input than Crown Cayman CWI103 (138 MBH against 103 MBH). Both list the same published AFUE of 83.1%.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Crown Cayman CWI103 | Crown Cayman CWI138 |
|---|---|---|
| Input | 103 MBH | 138 MBH |
| Heating capacity | 86 MBH | 115 MBH |
| Efficiency (AFUE) | 83.1 % | 83.1 % |
| Domestic hot water | Integrated tankless coil in the boiler body (water boiler, not a combi burner) | Integrated tankless coil in the boiler body (water boiler, not a combi burner) |
| Water volume | 10 gal | 12.2 gal |
| Dimensions (A × B × C) | 16 × 28 × 40-7/16" | 19-1/4 × 28 × 40-7/16" |
| Venting | Category I natural draft into a lined masonry or listed metal chimney | Category I natural draft into a lined masonry or listed metal chimney |
| Fuel | Natural gas or propane | Natural gas or propane |
| AHRI net rating | 75 MBH | 100 MBH |
| Cast-iron sections | 4 | 5 |
| Tankless heater rating | 2.5 GPM GPM | 3 GPM GPM |
Published ratings: the Crown Cayman CWI103 is rated 103 MBH input, 86 MBH heating capacity and 83.1% AFUE; the Crown Cayman CWI138 is rated 138 MBH input, 115 MBH heating capacity and 83.1% AFUE. Crown Cayman CWI138 lists 35 MBH more input than Crown Cayman CWI103 (138 MBH against 103 MBH). Both list the same published AFUE of 83.1%.
The boiler water content differs: the Crown Cayman CWI103 lists 10 gal, while the Crown Cayman CWI138 lists 12.2 gal. The dimensions differs: the Crown Cayman CWI103 lists 16 × 28 × 40-7/16", while the Crown Cayman CWI138 lists 19-1/4 × 28 × 40-7/16". The cast-iron sections differs: the Crown Cayman CWI103 lists 4, while the Crown Cayman CWI138 lists 5.
Both records print the same AFUE (83.1%), domestic-hot-water arrangement (Integrated tankless coil in the boiler body (water boiler, not a combi burner)), venting (Category I natural draft into a lined masonry or listed metal chimney) and fuel (Natural gas or propane), per the cited sources.
Crown Boiler Co.
The Crown Cayman CWI103 is a legacy cast-iron gas water boiler with an integrated tankless domestic coil: 103 MBH input over 4 sections with 86 MBH heating capacity and a 75 MBH AHRI net rating at 83.1% AFUE.
Crown Boiler Co.
The Crown Cayman CWI138 is a legacy cast-iron gas water boiler with an integrated tankless domestic coil: 138 MBH input over 5 sections with 115 MBH heating capacity and a 100 MBH AHRI net rating at 83.1% AFUE.
The Crown Cayman CWI138 lists 138 MBH, against 103 MBH on the Crown Cayman CWI103, per the cited documentation.
Both list the same AFUE of 83.1%.
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.