Viessmann · Vitocrossal (legacy CA3/CT3 and earlier CM2 generations)
Viessmann Vitocrossal 300 CT3-22
The Vitocrossal 300 CT3-22 steps the CT3 range to 846 MBH input (248 kW) with 827 MBH output at 97.8% combustion and 97.7% thermal efficiency.
Key figures
- Max input
- —
- Max CSA output
- —
- AFUE
- —
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Viessmann Vitocrossal 300 CT3-22 in practice
The CT3-22 is rated 846 MBH (248 kW) input and 827 MBH (242 kW) output with 97.8% combustion efficiency and 97.7% thermal efficiency. It shares the CT3 platform's vertical Inox-Crossal heat exchanger, 30 psig maximum operating pressure and 210°F maximum supply temperature.
The boiler shell weighs 1,114 lb (505 kg) and the complete unit 1,352 lb (613 kg), with 78.2 USG (296 L) of boiler water. Dimensions grow slightly to 1,594 x 684 x 1,808 mm (62¾ x 27 x 71¼ in) as shipped, and the internal vent pipe remains 8 in. (201 mm).
Best suited to
- Existing CT3-22 installations needing printed ratings
- Commercial loads between the CT3-17 and CT3-28
- Documentation for the second CT3 size
Applicability and support
- Model number
- CT3-22
- Canadian availability
- historical
- 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 Viessmann. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Input | 846 MBH | 248 kW, per the technical data manual |
| Output | ||
| Output | 827 MBH | 242 kW; tested to AHRI BTS-2000. |
| Efficiency | ||
| Combustion efficiency | 97.8 % | Per the printed rating table. |
| Thermal efficiency | 97.7 % | Per the printed rating table. |
| Venting and air | ||
| Vent pipe internal diameter | 8 in | 201 mm per the technical data manual. |
| Physical and connections | ||
| Weight, boiler shell | 1,114 lb | 505 kg |
| Overall weight (with insulation and control, less burner) | 1,352 lb | 613 kg |
| Boiler length as shipped (door removed) | 1,594 mm | Printed as 62¾ in |
| Width 1 (maximum shell width) | 684 mm | Printed as 27 in |
| Maximum height | 1,808 mm | Printed as 71¼ in |
| Operating limits and other | ||
| Fuel | Natural gas or liquid propane | Gas-fired condensing boiler; maximum supply temperature 210°F (99°C). |
| Boiler water content | 78.2 USG | Per the technical data manual. |
| Maximum operating pressure | 30 psig | 207 kPa; maximum operating temperature 210°F (99°C). |
| Boiler supply / return | Per model | Supply and return connections 2½ to 5 in. depending on size; boiler drain 1 in. |
Manuals
- Technical Data Manual — Vitocrossal 300 CT3 Series, doc 5285 871 - 055285 871 - 05 · 2016-01
- Installation Instructions — Vitocrossal 300 CT3, rev 0303 · 2015-10
- Service Instructions — Vitocrossal 300 CT3, rev 0404 · 2016-01
- Operating Instructions — Vitocrossal 300 CT3, rev 0202 · 2015-10
Alerts documented for this model
None documented yet.
Frequently asked questions
What is the CT3-22 rated at?
846 MBH (248 kW) input and 827 MBH (242 kW) output, with 97.8% combustion efficiency and 97.7% thermal efficiency.
How much does the CT3-22 weigh?
1,114 lb (505 kg) for the boiler shell and 1,352 lb (613 kg) complete with insulation and control, less burner.
What is the water content of the CT3-22?
78.2 USG (296 L) of boiler water, per the CT3 technical data manual.
Questions about the Viessmann Vitocrossal 300 CT3-22?
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
- Viessmann Vitocrossal 300 CT3-17 vs CT3-22Comparison
- Viessmann Vitocrossal 300 CT3-17Same series
- Viessmann Vitocrossal 300 CT3-28Same series
- Viessmann Vitocrossal 300 CT3-37Same series
- Viessmann Vitocrossal 300 CT3-46Same series
- Viessmann Vitocrossal 300 CT3-57Same series
- Viessmann Vitocrossal 300 CT3-72Same series
- Viessmann Vitocrossal 300 CT3-89Same series
- Vitocrossal (legacy CA3/CT3 and earlier CM2 generations) series hub
- Buying guide
Sources and verification
- Technical Data Manual — Vitocrossal 300 CT3 Series, doc 5285 871 - 05 · 5285 871 - 05 · accessed September 9, 2026
- Viessmann Canada — Historic manuals · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.