Navien · NFB700-C Commercial Boiler
Navien NFB700-500C
The Navien NFB700-500C is the entry model of the floor-standing NFB700-C commercial boiler series: 40 to 499 MBH of input with a 487 MBH heating capacity and a 423 MBH net AHRI water rating at 97.5% thermal efficiency.
Key figures
- Max input
- 499 MBH
- Max CSA output
- —
- AFUE
- —
- Min input
- 40 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Navien NFB700-500C in practice
The NFB700-500C fires from 40 to 499 MBH at a printed 97.5% thermal efficiency, with the product page listing a 487 MBH heating capacity and a 423 MBH net AHRI water rating (net figures are based on a piping and pickup allowance of 1.15). It is the smallest of the four floor-standing NFB700-C models and the first Navien floor-standing boiler size, sold under the series copy's "New NFB700-C Series" banner; the model page badge prints "Residential/Commercial" while the Canadian products grid lists the series under Commercial → Boilers.
The boiler weighs 622 lb dry and 843 lb with its 26.5 gallons of water, measures 23.8 x 72.1 x 31.0 in, and connects on 2" NPT water and 1" NPT gas fittings. Venting is 4" PVC, CPVC, approved polypropylene or approved stainless steel (or 4" special gas vent Type BH, Class III A/B/C) in a forced-draft direct-vent arrangement, with the series page stating venting up to 150 ft. The stainless fire-tube heat exchanger sits in a cold-rolled carbon steel casing, and the product pages print a 12–160 PSI water pressure range.
Best suited to
- Commercial hydronic plants whose load calculation lands between 40 and 499 MBH
- Projects moving up from wall-hung 300-plus MBH boilers into a floor-standing cabinet
- Light-commercial buildings wanting the lowest 40 MBH minimum fire in the NFB700-C line
Applicability and support
- Model number
- NFB700-500C
- 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 | ||
| Input, minimum | 40 MBH | Per the product page. |
| Input, maximum | 499 MBH | Per the product page. |
| Output | ||
| Heating capacity | 487 MBH | Per the product page. |
| Net AHRI water rating | 423 MBH | Net AHRI based on a piping and pickup allowance of 1.15, per the product page. |
| Efficiency | ||
| Thermal efficiency | 97.5 % | As printed on the product page (DOE test basis); the page labels the row "Thermal Efficiency", not AFUE. |
| Venting and air | ||
| Venting | 4" PVC, CPVC, approved polypropylene or approved stainless steel, or 4" special gas vent Type BH (Class III A/B/C) | Forced-draft direct vent per the product page; the series page states venting up to 150 ft. |
| Physical and connections | ||
| Weight | 622 lb | 622 lb dry; 843 lb with water, per the product page. |
| Width | 23.8 in | |
| Height | 72.1 in | |
| Depth | 31 in | |
| Water content | 26.5 gal | Per the product page. |
| Heating water connections | 2" NPT | Per the product page. |
| Gas connection | 1" NPT | Per the product page. |
| Operating limits and other | ||
| Fuel | Natural gas or propane | Ratings are the same for natural-gas models converted to propane use, per the product page; the series ships with a propane conversion kit. |
| Water pressure rating | 12 – 160 psi | 12–160 PSI water pressure range printed on the NFB700-C product pages. |
| Altitude rating | 10,100 ft | Per the NFB700-C series page. |
Manuals
Alerts documented for this model
None documented yet.
Frequently asked questions
What is the input range of the NFB700-500C?
40 to 499 MBH, per the product page, with a 487 MBH heating capacity and a 423 MBH net AHRI water rating at 97.5% thermal efficiency.
How does the NFB700-500C compare with the NFB700-600C?
The two share the same 622 lb cabinet, 26.5 gallons of water, 2" NPT water connections and 4" venting. The 600C fires to 599 MBH against the 500C's 499 MBH, with its capacity and net AHRI ratings stepping from 487/423 to 584/508 MBH; both start at a 40 MBH minimum.
Is the NFB700-500C a combi boiler?
No. Navien lists the NFB700-C as a condensing fire-tube boiler series; it produces space heating only, so domestic hot water is handled by external equipment.
Questions about the Navien NFB700-500C?
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 — NFB700-C series · accessed September 9, 2026
- Navien Canada — NFB700-500C product page · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.