Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
Boilers.ca is a brand of ROMA Heating & Cooling · Licensed gas contractor LGA0202903
Comparison
Verdict in brief
Crown Cayman CWI138 and Crown Cayman CWI172 are two non-condensing boilers from the Crown Boiler Co. Cayman (legacy) line. Published ratings: Crown Cayman CWI138 at 138 MBH input, 115 MBH heating capacity and 83.1% AFUE; Crown Cayman CWI172 at 172 MBH input, 144 MBH heating capacity and 83.2% AFUE. Crown Cayman CWI172 lists 34 MBH more input than Crown Cayman CWI138 (172 MBH against 138 MBH). Crown Cayman CWI172 carries the higher published AFUE at 83.2%, against 83.1%.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Crown Cayman CWI138 | Crown Cayman CWI172 |
|---|---|---|
| Input | 138 MBH | 172 MBH |
| Heating capacity | 115 MBH | 144 MBH |
| Efficiency (AFUE) | 83.1 % | 83.2 % |
| 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 | 12.2 gal | 14.4 gal |
| Dimensions (A × B × C) | 19-1/4 × 28 × 40-7/16" | 22-1/2 × 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 | 100 MBH | 125 MBH |
| Cast-iron sections | 5 | 6 |
| Tankless heater rating | 3 GPM GPM | 3.5 GPM GPM |
Published ratings: the Crown Cayman CWI138 is rated 138 MBH input, 115 MBH heating capacity and 83.1% AFUE; the Crown Cayman CWI172 is rated 172 MBH input, 144 MBH heating capacity and 83.2% AFUE. Crown Cayman CWI172 lists 34 MBH more input than Crown Cayman CWI138 (172 MBH against 138 MBH). Crown Cayman CWI172 carries the higher published AFUE at 83.2%, against 83.1%.
The boiler water content differs: the Crown Cayman CWI138 lists 12.2 gal, while the Crown Cayman CWI172 lists 14.4 gal. The dimensions differs: the Crown Cayman CWI138 lists 19-1/4 × 28 × 40-7/16", while the Crown Cayman CWI172 lists 22-1/2 × 28 × 40-7/16". The cast-iron sections differs: the Crown Cayman CWI138 lists 5, while the Crown Cayman CWI172 lists 6.
Both records print the same 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 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.
Crown Boiler Co.
The Crown Cayman CWI172 is a legacy cast-iron gas water boiler with an integrated tankless domestic coil: 172 MBH input over 6 sections with 144 MBH heating capacity and a 125 MBH AHRI net rating at 83.2% AFUE.
The Crown Cayman CWI172 lists 172 MBH, against 138 MBH on the Crown Cayman CWI138, per the cited documentation.
The Crown Cayman CWI172 carries the higher published AFUE at 83.2%, against 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.