Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The B2HB 26, 94 and B2HB 35, 125 share everything except the top of the firing range: both fire from 19 MBH natural gas (31 MBH propane), weigh 110 lb (50 kg), print 95.0% AFUE and carry a 45 psig rating. The 35, 125 adds 31 MBH of natural gas ceiling — 125 against 94 MBH — with a 102 MBH Net AHRI rating against 77.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Viessmann Vitodens 200-W B2HB 26, 94 | Viessmann Vitodens 200-W B2HB 35, 125 |
|---|---|---|
| CSA input, minimum (natural gas) | 19 MBH | 19 MBH |
| CSA input, maximum (natural gas) | 94 MBH | 125 MBH |
| CSA input (liquid propane) | 31-94 MBH | 31-125 MBH |
| CSA output / DOE heating capacity (natural gas) | 18-88 MBH | 18-117 MBH |
| Net AHRI rating | 77 MBH | 102 MBH |
| Efficiency (AFUE) | 95 % | 95 % |
| Weight | 110 lb | 110 lb |
| Maximum operating pressure | 45 psig | 45 psig |
The B2HB 26, 94 and 35, 125 are twins below the top of the range: both start at 19 MBH on natural gas and 31 MBH on propane, both output 18 MBH at the bottom, and both use the 110 lb (50 kg) compact cabinet with 1.02 USG of boiler water and a 45 psig maximum operating pressure.
Maximum input is the separator: 94 MBH natural gas (31-94 MBH propane) on the 26, 94 against 125 MBH (31-125 MBH propane) on the 35, 125. Output tops at 88 and 117 MBH respectively, with Net AHRI ratings of 77 and 102 MBH. Both print 95.0% AFUE.
Both models are named in Viessmann Canada's heat-exchanger replacement safety notice for units built between September 1, 2014 and April 25, 2017, and neither can be common-vented with another appliance. Because minimum fire is identical, the 35, 125's extra ceiling costs nothing in low-load behaviour.
Viessmann
The Vitodens 200-W B2HB 26, 94 steps the previous-generation line to 94 MBH: 19 to 94 MBH natural gas input (31 to 94 MBH on propane) at 95.0% AFUE in the 110 lb (50 kg) compact cabinet.
The Vitodens 200-W B2HB 35, 125 is the largest model of the B2HB compact chassis: 19 to 125 MBH natural gas input (31 to 125 MBH propane) at 95.0% AFUE with a 102 MBH Net AHRI rating.
Only the maximum input: 94 vs 125 MBH natural gas, with 88 vs 117 MBH output and Net AHRI ratings of 77 vs 102 MBH. Minimum fire, weight, dimensions and AFUE are identical.
Yes — B2HB models 19, 26 and 35 manufactured between September 1, 2014 and April 25, 2017 are covered by Viessmann Canada's heat-exchanger replacement notice.
The B2HB 26, 94 tops out at 94 MBH, so a design load near or above that figure points to the 35, 125 — with no penalty at low fire since both start at 19 MBH.
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.