Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The Viessmann Vitodens 200-W B2HE-150 and Navien NFB-175H are 95% AFUE heating-only condensing boilers for larger homes, with Navien offering the higher ceiling and the deeper modulation: the NFB-175H fires 13.3 to 175 MBH while the B2HE-150 runs 14 to 150 MBH. Viessmann's claimed 14:1 turndown and 179 lb flagship cabinet trade against Navien's 121 lb, 27.6-inch-tall package; a heat-loss calculation settles it.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Viessmann Vitodens 200-W B2HE-150 | Navien NFB-175H |
|---|---|---|
| Input, minimum (natural gas) | 14 MBH | 13.3 MBH |
| Input, maximum (natural gas) | 150 MBH | 175 MBH |
| Efficiency (AFUE) | 95 % | 95 % |
| Fuel | Natural gas or liquid propane | Natural gas or propane |
| Weight | 179 lb | 121 lb |
| Width | 17.75 in | 17.3 in |
| Height | 39 in | 27.6 in |
| Depth | 21.75 in | 17.3 in |
| Domestic hot water | Not a combi; pair with an indirect tank | Heating-only boiler; domestic hot water via an indirect tank or separate appliance |
Both are heating-only condensing boilers rated 95% AFUE (Viessmann's Canadian page also cites up to 98% at full modulation as a separate figure) on natural gas or propane, and both sit in the 150-175 MBH band. Navien lists the NFB-175H at 13.3 to 175 MBH input, while Viessmann lists the B2HE-150 at 14 to 150 MBH (4.1 to 44.0 kW) — the Navien adds about 25 MBH of top-end headroom for homes on the edge of the class.
Minimum fires are nearly level at 13.3 versus 14 MBH, yet the published turndown claims differ a lot: Viessmann claims up to 14:1 for the B2HE while Navien's quick-facts sheet is the source of its low-fire figure. At these firing floors both boilers handle mild-weather part load credibly; the difference that shows up on a design-day calculation is the 175 MBH ceiling of the NFB against the B2HE-150's 150 MBH.
The physical packages are opposite in feel: the B2HE-150 weighs 179 lb (81 kg) and measures 17.75 by 21.75 by 39 inches, while the NFB-175H weighs 121 lb (148 lb with water) at 17.3 by 17.3 by 27.6 inches. Both are heating-only with an indirect tank for hot water, both vent in plastic pipe within each maker's published limits, and both should be selected after a heat-loss calculation.
Viessmann
The Vitodens 200-W B2HE-150 is the larger-cabinet mid-high model of Viessmann Canada's B2HE series: 14 to 150 MBH input at 95% AFUE, weighing 179 lb with the 7-inch touchscreen of the flagship platform.
Navien
The Navien NFB-175H is a heating-only condensing boiler firing 13.3 to 175 MBH at 95.0% AFUE, with 1 1/4" NPT heating connections and no integrated hot-water production — hot water comes from an external tank.
The Navien NFB-175H reaches 175 MBH of input against 150 MBH for the Viessmann B2HE-150, so design loads between 150 and 175 MBH point to the Navien.
No. The B2HE-150 is 39 inches tall and 179 lb, while the NFB-175H is 27.6 inches tall and 121 lb (148 lb with water), which can decide retrofit fit.
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 8, 2026. Last updated September 8, 2026. Technical reviewer: not yet assigned.