Viessmann · Vitodens 100-W (legacy B1HA / B1KA and earlier)
Viessmann Vitodens 100-W WB1B 26
The Vitodens 100-W WB1B 26 is the smaller WB1B boiler: 37 to 91 MBH NG/LPG input at 94.0% AFUE in a 78 lb (34.1 kg) wall-hung cabinet.
Key figures
- Max input
- 91 MBH
- Max CSA output
- —
- AFUE
- 94 %
- Min input
- 37 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Viessmann Vitodens 100-W WB1B 26 in practice
The WB1B 26 is the second-generation Vitodens 100-W: a natural gas or liquid propane wall-mounted condensing boiler rated 37-91 MBH (10.8-26.7 kW) input, 34-83 MBH (9.9-24.3 kW) output and a 72 MBH Net I=B=R rating at 94.0% AFUE.
It weighs 78 lb (34.1 kg) with a 95 lb (43 kg) shipping weight, holds 0.87 USG of boiler water and is rated 45 psig maximum operating pressure. Dimensions are 400 x 360 x 725 mm (15¾ x 14⅛ x 28½ in). The WB1B generation is documented in Viessmann Canada's historic manuals with its own technical data manual (doc 5369 277 v1.5).
Best suited to
- Owners of existing WB1B 26 units looking up printed ratings
- Residential loads from 37 MBH on natural gas or propane
- Documentation for the WB1B generation before the B1HA/B1KA series
Applicability and support
- Model number
- WB1B 26
- 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 | ||
| CSA input, minimum (NG/LPG) | 37 MBH | 10.8 kW, per the technical data manual |
| CSA input, maximum (NG/LPG) | 91 MBH | 26.7 kW, per the technical data manual |
| Output | ||
| CSA output / DOE heating capacity | 34-83 MBH | 9.9-24.3 kW, based on 140°F / 120°F supply/return |
| Net I=B=R rating | 72 MBH | Based on piping and pick-up allowance of 1.15. |
| Efficiency | ||
| Efficiency (AFUE) | 94 % | 94.0% AFUE on both WB1B models per the technical data manual. |
| Physical and connections | ||
| Weight | 78 lb | 34.1 kg; shipping weight 95 lb (43 kg). |
| Overall width | 400 mm | 15¾ in |
| Overall depth | 360 mm | 14⅛ in |
| Overall height | 725 mm | 28½ in |
| Operating limits and other | ||
| Fuel | Natural gas or liquid propane | NG minimum supply pressure 4 in. w.c.; LPG 10 in. w.c. |
| Boiler water content | 0.87 USG | 3.3 L. |
| Maximum operating pressure | 45 psig | 3 bar at 210°F (99°C). |
| Boiler heating supply / return | ¾ in. NPTM | Gas supply ¾ in. NPTF. |
Manuals
- Technical Data Manual — Vitodens 100-W B1HA Series and B1KA Combi Boiler, doc 5784 566 - 125784 566 - 12 · 2025-04
- Installation and Service Instructions — Vitodens 100-W B1HA/B1KA, rev 2222 · 2025-08
- Technical Data Manual — Vitodens 100-W WB1A Series, doc 5347 963 v1.15347 963 v1.1 · 2007-10
- Technical Data Manual — Vitodens 100-W WB1B Series, doc 5369 277 v1.55369 277 v1.5 · 2010-01
Alerts documented for this model
None documented yet.
Frequently asked questions
What is the WB1B 26 rated at?
37-91 MBH (10.8-26.7 kW) NG/LPG input, 34-83 MBH (9.9-24.3 kW) output, a 72 MBH Net I=B=R rating and 94.0% AFUE.
Does the WB1B 26 run on propane?
Yes. The WB1B technical data manual prints combined natural gas and LPG ratings, with a 4 in. w.c. minimum NG supply pressure and 10 in. w.c. for LPG.
What manual covers the WB1B 26?
The Vitodens 100-W WB1B technical data manual (doc 5369 277 v1.5, 01/2010) and the WB1B installation and service instructions, both linked on this record.
Questions about the Viessmann Vitodens 100-W WB1B 26?
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 Vitodens 100-W WB1B 26 vs WB1B 35Comparison
- Viessmann Vitodens 100-W B1HA 26, 94Same series
- Viessmann Vitodens 100-W B1HA 35, 125Same series
- Viessmann Vitodens 100-W B1KA 35, 125Same series
- Viessmann Vitodens 100-W WB1A 8-24Same series
- Viessmann Vitodens 100-W WB1A 8-30Same series
- Viessmann Vitodens 100-W WB1B 35Same series
- Vitodens 100-W (legacy B1HA / B1KA and earlier) series hub
- Buying guide
Sources and verification
- Technical Data Manual — Vitodens 100-W WB1B Series, doc 5369 277 v1.5 · 5369 277 v1.5 · 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.