Viessmann · Vitocrossal (legacy CA3/CT3 and earlier CM2 generations)
Viessmann Vitocrossal 300 CT3-57
The Vitocrossal 300 CT3-57 is the largest CT3 model on the 800 mm shell: 2160 MBH input (633 kW), 2094 MBH output and 96.9% combustion and 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 CT3-57 in practice
The CT3-57 is rated 2160 MBH (633 kW) input and 2094 MBH (614 kW) output at 96.9% combustion and thermal efficiency. It is the largest CT3 size on the 800 mm shell and 10 in. vent pipe before the line steps to the 951 mm shell used by the 72 and 89.
The boiler shell weighs 1,995 lb (905 kg) and the complete unit 2,322 lb (1,053 kg), with 150.6 USG (570 L) of boiler water and a 1,985 x 800 x 2,023 mm (78⅛ x 31⅛ x 79⅝ in) shipping envelope.
Best suited to
- Existing CT3-57 installations needing printed ratings
- Commercial loads between the CT3-46 and CT3-72
- Documentation for the last 800 mm-shell CT3 size
Applicability and support
- Model number
- CT3-57
- 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 | 2,160 MBH | 633 kW, per the technical data manual |
| Output | ||
| Output | 2,094 MBH | 614 kW; tested to AHRI BTS-2000. |
| Efficiency | ||
| Combustion efficiency | 96.9 % | Per the printed rating table. |
| Thermal efficiency | 96.9 % | Per the printed rating table. |
| Venting and air | ||
| Vent pipe internal diameter | 10 in | 251 mm per the technical data manual. |
| Physical and connections | ||
| Weight, boiler shell | 1,995 lb | 905 kg |
| Overall weight (with insulation and control, less burner) | 2,322 lb | 1053 kg |
| Boiler length as shipped (door removed) | 1,985 mm | Printed as 78⅛ in |
| Width 1 (maximum shell width) | 800 mm | Printed as 31⅛ in |
| Maximum height | 2,023 mm | Printed as 79⅝ 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 | 150.6 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 CT3-57 rated at?
2160 MBH (633 kW) input and 2094 MBH (614 kW) output, with 96.9% combustion efficiency and 96.9% thermal efficiency.
How much does the CT3-57 weigh?
1,995 lb (905 kg) as a boiler shell and 2,322 lb (1,053 kg) complete with insulation and control, less burner.
Does the CT3-57 have the same vent size as the CT3-72?
No — the CT3-57 uses a 10 in. vent pipe; the CT3-72 and CT3-89 step up to 12 in. (301 mm).
Questions about the Viessmann Vitocrossal 300 CT3-57?
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 CT3-57 vs CT3-72Comparison
- Viessmann Vitocrossal 300 CT3-17Same series
- Viessmann Vitocrossal 300 CT3-22Same series
- Viessmann Vitocrossal 300 CT3-28Same series
- Viessmann Vitocrossal 300 CT3-37Same series
- Viessmann Vitocrossal 300 CT3-46Same 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.