Viessmann · Vitocrossal 300 (CU3A)
Viessmann Vitocrossal 300 CU3A-160
The Vitocrossal 300 CU3A-160 is the second-largest CU3A model: 43,000 to 160,000 BTU (12.6 to 47 kW) of input at 95% AFUE, weighing 352 lb (160 kg) in the deeper floor-standing cabinet.
Key figures
- Max input
- 160 MBH
- Max CSA output
- —
- AFUE
- 95 %
- Min input
- 43 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Viessmann Vitocrossal 300 CU3A-160 in practice
The CU3A-160 fires from a 43,000 BTU (12.6 kW) minimum input up to 160,000 BTU (47 kW) maximum at 95% AFUE. Along with the CU3A-199 it moves to the heavier 352 lb (160 kg) chassis with a 31½-inch (801 mm) depth — about 4½ inches deeper than the CU3A-94/125 cabinet.
The series combines a vertical stainless steel Inox-Crossal heat exchanger, a MatriX dome gas burner and Lambda Pro combustion control with a user-friendly Vitotronic 200 control, and the page cites a 5:1 turndown ratio, operation up to 194°F (90°C) and high-altitude operation up to 10,000 ft (3,000 m).
Viessmann Canada markets the CU3A for new construction and retrofits, including high-mass cast iron radiator homes and high DHW loads. Multi-boiler installations can run up to 1592 MBH, and no dedicated boiler pump is required.
Best suited to
- Homes and light-commercial plants with loads up to about 160 MBH
- Retrofits replacing mid-size floor-standing boilers with a condensing unit
- Plants where the CU3A-125's ceiling is short but a 199 is not needed
Applicability and support
- Model number
- CU3A-160
- 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 | 43 MBH | 43,000 BTU (12.6 kW), per the Canadian product page |
| Input, maximum | 160 MBH | 160,000 BTU (47 kW), per the Canadian product page |
| Efficiency | ||
| Efficiency (AFUE) | 95 % | 95% for all models per the Canadian product page. |
| Venting and air | ||
| Maximum vent run | 198 ft | Vent lengths up to 198 ft per the Canadian product page. |
| Physical and connections | ||
| Weight | 352 lb | 160 kg |
| Width | 26 in | 660 mm |
| Depth | 31.5 in | 801 mm |
| Height | 61.5 in | 1562 mm with the control interface closed; 67 in (1707 mm) with it open |
| Operating limits and other | ||
| Turndown ratio | 5:1 | Per the Canadian product page. |
| Maximum altitude | 10,000 ft | High-altitude operation up to 10,000 ft (3,000 m) per the Canadian product page; the page prints no derating note. |
| Fuel type | Natural gas (NG) or liquid propane gas (LPG) | As printed on the Canadian product page. |
Manuals
Alerts documented for this model
Frequently asked questions
What is the CU3A-160's firing range?
From a 43,000 BTU (12.6 kW) minimum input up to 160,000 BTU (47 kW) maximum, per the Canadian product page. The CU3A-199 shares the same 43,000 BTU minimum.
How heavy is the CU3A-160?
352 lb (160 kg), per the Canadian product page — the same weight as the CU3A-199, and 77 lb more than the 275 lb CU3A-125. Its cabinet is 31½ inches (801 mm) deep against 27 inches (684 mm) on the smaller models.
How efficient is the CU3A-160?
95% AFUE on all CU3A models per the page; the Inox-Crossal heat exchanger is described as reaching efficiencies of up to 98%.
Questions about the Viessmann Vitocrossal 300 CU3A-160?
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 CU3A-125 vs CU3A-160Comparison
- Viessmann Vitocrossal 300 CU3A-160 vs CU3A-199Comparison
- Viessmann Vitocrossal 300 CU3A-94 vs CU3A-160Comparison
- Viessmann Vitocrossal 300 CU3A-94Same series
- Viessmann Vitocrossal 300 CU3A-125Same series
- Viessmann Vitocrossal 300 CU3A-199Same series
- Vitocrossal 300 (CU3A) series hub
- Buying guide
Sources and verification
- Viessmann Canada — Vitocrossal 300 CU3A product page · accessed September 8, 2026
- Service Instructions — Vitocrossal 300 CU3A, Canadian models 26, 35, 45, 57, 94, 125, 160, 199, doc 5673 649 - 20 · 5673 649 - 20 · accessed September 8, 2026
Facts checked September 8, 2026. Last updated September 8, 2026. Technical reviewer: not yet assigned.