Viessmann · Vitocrossal 200 (CM2, GW6B)
Viessmann Vitocrossal 200 CM2-186
The Vitocrossal 200 CM2-186 is the smallest model of the CM2 (GW6B) line: 131 to 663 MBH natural-gas input (38.5 to 194 kW) at 95% combustion efficiency, 5:1 turndown, in a 726 lb (329 kg) floor-standing unit.
Key figures
- Max input
- 663 MBH
- Max CSA output
- —
- AFUE
- —
- Min input
- 131 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Viessmann Vitocrossal 200 CM2-186 in practice
The CM2-186 is the entry size of the Vitocrossal 200 CM2 series on the Vitotronic 300 GW6B control. The product page prints its natural-gas input from 131,000 to 663,000 BTU (38.5 to 194 kW) and its combustion efficiency at 95% — the figure shared by all three small models (CM2-186/246/311).
The boiler is a gas-fired floor-standing condensing unit with a stainless steel Inox-Crossal heat exchanger and a fully modulating pre-mix cylinder burner, on natural gas or liquid propane with simple electronic conversion. It weighs 726 lb (329 kg), and the small-manual service instructions (doc 5584 109 - 16, 05/2021) cover the 186–311 size range.
The series runs stand-alone or as primary/secondary cascade control of up to eight boilers without a separate cascade controller, common vents up to four boilers, handles altitude to 10,000 ft with electronic adjustment and requires no dedicated boiler pump, per the page.
Best suited to
- Small commercial plants whose load fits between about 131 and 663 MBH
- Projects wanting the GW6B control platform at the entry CM2 size
- Cascades where the smallest CM2 steps keep plant capacity granular
Applicability and support
- Model number
- CM2-186
- Canadian availability
- available
- Production status
- current
- 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, minimum (natural gas) | 131 MBH | 131,000 BTU (38.5 kW), per the product page |
| Input, maximum (natural gas) | 663 MBH | 663,000 BTU (194 kW), per the product page |
| Efficiency | ||
| Combustion efficiency | 95 % | Per the product-page efficiency row. |
| Physical and connections | ||
| Weight | 726 lb | 329 kg |
| Operating limits and other | ||
| Turndown ratio | 5:1 | Per the product page. |
Manuals
Alerts documented for this model
Frequently asked questions
What is the firing range of the CM2-186?
Natural-gas input runs 131,000 to 663,000 BTU (38.5 to 194 kW) per the product page — the smallest range in the CM2 line.
What efficiency does the CM2-186 print?
95% combustion efficiency per the product-page efficiency row, shared by the CM2-186/246/311; the larger CM2 models print 95.1%.
Which service manual covers the CM2-186?
The CM2 service instructions for the 186 to 311 models, doc 5584 109 - 16 dated 05/2021, which covers the CM2-186, CM2-246 and CM2-311.
Questions about the Viessmann Vitocrossal 200 CM2-186?
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 200 CM2-186 vs CM2-246Comparison
- Viessmann Vitocrossal 200 CM2-246Same series
- Viessmann Vitocrossal 200 CM2-311Same series
- Viessmann Vitocrossal 200 CM2-400Same series
- Viessmann Vitocrossal 200 CM2-500Same series
- Viessmann Vitocrossal 200 CM2-620Same series
- Vitocrossal 200 (CM2, GW6B) series hub
- Buying guide
Sources and verification
- Viessmann Canada — Vitocrossal 200 CM2 product page · accessed September 9, 2026
- Service Instructions — Vitocrossal 200 CM2 Series 186 to 311, doc 5584 109 - 16 · 5584 109 - 16 · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.