Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The WB2B-80 and WB2B-105 are the two large-chassis WB2B boilers and share the 225 lb (102 kg) cabinet, 3.4 USG water content, 60 psig rating, 96.1% AFUE and a 104 MBH NG/LPG minimum input. The WB2B-105 fires to 370 MBH against 285 MBH and is the only WB2B size with a printed 94.5% thermal-efficiency row (ANSI Z21.13/CSA 4.9).
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Viessmann Vitodens 200-W WB2B-80 | Viessmann Vitodens 200-W WB2B-105 |
|---|---|---|
| CSA input, minimum (NG/LPG) | 104 MBH | 104 MBH |
| CSA input, maximum (NG/LPG) | 285 MBH | 370 MBH |
| CSA output / DOE heating capacity | 95-260 MBH | 98-350 MBH |
| Net I=B=R rating | 226 MBH | 304 MBH |
| Efficiency (AFUE) | 96.1 % | 96.1 % |
| CSA thermal efficiency (ANSI Z21.13/CSA 4.9) | — | 94.5 % |
| Weight | 225 lb | 225 lb |
| Boiler water content | 3.4 USG | 3.4 USG |
| Maximum operating pressure | 60 psig | 60 psig |
Both boilers share the WB2B large chassis: a 104 MBH (30 kW) minimum input, 95 MBH output floor, 96.1% AFUE, 225 lb (102 kg) weight, 3.4 USG water content, 60 psig maximum operating pressure and 19 x 21 x 33½ in (480 x 530 x 850 mm) dimensions.
Maximum input separates them: 285 MBH (83 kW) on the WB2B-80 against 370 MBH (108 kW) on the WB2B-105, with outputs of 95-260 and 98-350 MBH and Net I=B=R ratings of 226 and 304 MBH. The WB2B-105 is the only WB2B model with a printed CSA thermal efficiency row — 94.5% per ANSI Z21.13/CSA 4.9.
The technical data manual prints an altitude derate specific to the WB2B-105: 14% at 5,000 ft and 28% at 10,000 ft, averaging 2.8% per 1,000 ft. Both models support multi-boiler installations with the Vitocontrol-S cascade control.
Viessmann
The Vitodens 200-W WB2B-80 opens the WB2B large chassis: 104 to 285 MBH NG/LPG input at 96.1% AFUE in a 225 lb (102 kg) wall-hung boiler.
Viessmann
The Vitodens 200-W WB2B-105 is the largest WB2B boiler: 104 to 370 MBH NG/LPG input at 96.1% AFUE with a printed 94.5% thermal efficiency (ANSI Z21.13/CSA 4.9).
Yes. Both weigh 225 lb (102 kg) and share the 19 x 21 x 33½ in (480 x 530 x 850 mm) cabinet with 3.4 USG of boiler water.
It is the only WB2B size with a printed CSA thermal efficiency row: 94.5% per ANSI Z21.13/CSA 4.9, alongside the range's 96.1% AFUE.
Yes — the technical data manual prints a 14% derate at 5,000 ft and 28% at 10,000 ft (average 2.8% per 1,000 ft) for the WB2B-105.
A consultation includes a heat-loss review so the size is right the first time.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.