Crown Boiler Co. · Cayman (legacy)
Crown Cayman CWI138
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.
Key figures
- Max input
- 138 MBH
- Max CSA output
- —
- AFUE
- 83.1 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Crown Cayman CWI138 in practice
The Cayman CWI138 is documented in the CWI specification table (Table 1) as a Category I, natural-draft cast-iron hot water boiler: 138 MBH input over 5 sections, 115 MBH heating capacity, a 100 MBH AHRI net rating (1.15 allowance) and 83.1% AFUE. Boiler water volume is 12.2 US gallons.
The model carries an integrated tankless domestic-water coil in the boiler body — rated 3 GPM at the specification-table conditions (40°F inlet, 140°F outlet, 190°F boiler water) — and runs natural or LP gas. The tankless heater is included on CWI103–CWI276 and optional on CWI311–CWI380.
The Cayman is legacy — absent from the current Velocity Boiler Works menu — so productStatus is 'discontinued'. Boilers.ca documents this model at model level from the hosted CWI manual; no official Canadian-sales statement was found, so canadianStatus stays 'unknown', and gas, combustion and venting work belongs with a licensed contractor.
Best suited to
- Owners documenting an installed Cayman against the CWI specification table
- Service planning for cast-iron natural-draft boilers with integrated tankless coils
- Legacy-replacement research in the 138-MBH-input class
Applicability and support
- Model number
- CWI138
- Canadian availability
- unknown
- Production status
- discontinued
- ROMA supplies
- Confirmed at consultation
- ROMA services
- Confirmed at consultation
- Warranty
- Not verified
Where ROMA provides on-site service
On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.
Specifications
Published specifications
Values as published by Crown Boiler Co.. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input | 138 MBH | Input per the CWI specification table (Table 1). |
| Output | ||
| Heating capacity | 115 MBH | Heating capacity per the CWI specification table (Table 1). |
| AHRI net rating | 100 MBH | AHRI net rating based on a piping and pickup allowance of 1.15 per the specification table note. |
| Efficiency | ||
| Efficiency (AFUE) | 83.1 % | AFUE per the CWI specification table (Table 1). |
| Domestic hot water | ||
| Tankless heater rating | 3 GPM GPM | Tankless heater rating per the specification table — based on 40°F inlet water, 140°F outlet water and 190°F boiler water, with 5-minute intermittent draws and 10 minutes between draws. The tankless heater is included on CWI103–CWI276 and optional on CWI311–CWI380. |
| Domestic hot water | Integrated tankless coil in the boiler body (water boiler, not a combi burner) | CWI103–CWI276 include a tankless heater for domestic hot water generation; it is optional equipment on CWI311–CWI380. A mixing valve is required in the tankless piping per the manual. |
| Venting and air | ||
| Venting | Category I natural draft into a lined masonry or listed metal chimney | Draft-diverter-equipped Category I appliance per the CWI installation manual product description. |
| Physical and connections | ||
| Cast-iron sections | 5 | Number of sections per the CWI specification table (Table 1). |
| Dimensions (A × B × C) | 19-1/4 × 28 × 40-7/16" | Boiler dimensions A, B and C (inches) per the CWI specification table (Table 1). |
| Water volume | 12.2 gal | Boiler water volume per the CWI specification table (Table 1). |
| Operating limits and other | ||
| Fuel | Natural gas or propane | Natural or LP gas per the CWI specification table. |
Alerts documented for this model
None documented yet.
Frequently asked questions
What are the CWI138's ratings?
138 MBH input, 115 MBH heating capacity and a 100 MBH AHRI net rating at 83.1% AFUE per the CWI specification table.
Does the CWI138 run on propane?
Yes — CWI103–CWI276 are natural or LP gas per the CWI specification table.
Is the Cayman a combi boiler?
It is a cast-iron water boiler with an integrated tankless domestic coil — not a modulating combi. The tankless heater is standard on CWI103–CWI276 and optional on CWI311–CWI380.
Questions about the Crown Cayman CWI138?
Describe what the boiler is doing and get a straight answer about the next step.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Compare and explore
- Crown Cayman CWI103 vs CWI138Comparison
- Crown Cayman CWI138 vs CWI172Comparison
- Crown Cayman CWI103Same series
- Crown Cayman CWI172Same series
- Crown Cayman CWI207Same series
- Crown Cayman CWI241Same series
- Crown Cayman CWI276Same series
- Crown Cayman CWI311Same series
- Crown Cayman CWI346Same series
- Crown Cayman CWI380Same series
- Cayman (legacy) series hub
- Buying guide
Sources and verification
- crownboiler.com — Cayman (CWI) legacy product page · accessed September 9, 2026
- CWI Series Gas-Fired Natural Draft Water Boilers — Installation Instructions (PDF) · accessed September 9, 2026
Facts checked September 8, 2026. Last updated September 8, 2026. Technical reviewer: not yet assigned.