Navien NHB-80H
The Navien NHB-80H is the 80 MBH member of the compact NHB-H series: 8 to 80 MBH input at 95.0% AFUE, keeping the 8 MBH minimum fire and the 73 lb, 23.8-inch-tall cabinet of the NHB-55H.
Key figures
- Max input
- 80 MBH
- Max CSA output
- —
- AFUE
- 95 %
- Min input
- 8 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Navien NHB-80H in practice
The NHB-80H shares the NHB-55H's 8 MBH minimum fire and 73 lb cabinet while raising the ceiling to 80 MBH, so it covers the detached homes whose calculated load outgrows the 55H without any change to the installation footprint. Navien's quick facts list a 10:1 turndown for this model.
Like every NHB-H it is heating-only with domestic hot water from an indirect tank or a separate appliance, and its control table carries no DHW codes. The unit measures 17.3 x 12.8 x 23.8 in, connects on 1" NPT heating fittings with a 3/4" NPT gas connection, and vents in 2" or 3" PVC to 65 or 150 equivalent feet per the installation manual.
Best suited to
- Small detached homes whose heat-loss calculation fits between 55 and 80 MBH
- Homes wanting the NHB-55H's low minimum fire with more headroom
- Compact retrofits where every inch of the mechanical room is spoken for
Applicability and support
- Model number
- NHB-80H
- 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 Navien. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Heating input, minimum | 8 MBH | Space-heating input. |
| Heating input, maximum | 80 MBH | Space-heating input. |
| Efficiency | ||
| Efficiency (AFUE) | 95 % | 95.0% AFUE per the installation manual. |
| Domestic hot water | ||
| Domestic hot water | Heating-only boiler; domestic hot water via an indirect tank or separate appliance | |
| Venting and air | ||
| Venting | PVC, CPVC or approved polypropylene; 2" or 3" | Canada: plastic venting must meet ULC S636 where required. |
| Max. equivalent vent length, 2" | 65 ft | |
| Max. equivalent vent length, 3" | 150 ft | |
| Physical and connections | ||
| Weight | 73 lb | 33 kg; per the installation manual. |
| Width | 17.3 in | |
| Height | 23.8 in | |
| Depth | 12.8 in | |
| Gas connection | 3/4" NPT | |
| Heating water connections | 1" NPT | |
| Operating limits and other | ||
| Fuel | Natural gas or propane | Separate Navien ratings per fuel. |
| Altitude rating | 10,100 ft | Per installation manual. |
| System water pressure | 12 – 30 psi | |
Manuals
Alerts documented for this model
Frequently asked questions
How does the NHB-80H compare with the NHB-55H?
Both fire down to 8 MBH and weigh 73 lb in the same 17.3 x 12.8 x 23.8 in cabinet; the 80H's maximum input is 80 MBH against 55 MBH on the 55H.
What turndown does Navien publish for the NHB-80H?
Navien's quick facts list 10:1 turndown for the NHB-80H, matching its 8,000 to 80,000 BTU/h input range.
Can the NHB-80H heat a whole house?
If the room-by-room heat-loss calculation fits within its 80 MBH ceiling, yes. Beyond that, the NHB-110H and NHB-150H extend the series to 110 and 150 MBH.
Questions about the Navien NHB-80H?
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.
Sources and verification
- Navien Canada — NHB-H series · accessed September 7, 2026
- NHB-H Installation and Operational Manual (EN) · accessed September 7, 2026
- NHB-H Service Manual, Ver 1.00 (July 2023) · Ver 1.00 · accessed September 7, 2026
Facts checked September 7, 2026. Last updated September 7, 2026. Technical reviewer: not yet assigned.