Navien · NCB-E Combi (previous generation)
Navien NCB-150E
The Navien NCB-150E is a previous-generation wall-hung condensing combi from the discontinued NCB-E series: 12 to 60 MBH heating input, 56 MBH capacity at 95.0% AFUE, and DHW input to 120,000 BTU/h.
Key figures
- Max input
- 60 MBH
- Max CSA output
- —
- AFUE
- 95 %
- Min input
- 12 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Navien NCB-150E in practice
The NCB-150E is one of the four NCB-E combis that preceded the current NCB-H line; Navien lists the series (NCB-150E, 180E, 210E and 240E) under Discontinued Products on both official sites. The NCB-E specification sheet prints 12–60 MBH heating input with 56 MBH heating capacity, a 49 MBH net AHRI water rating and 95.0% AFUE.
Domestic hot water is produced on demand inside the combi: the spec sheet prints DHW input of 12,000–120,000 BTU/h and 2.6 GPM at a 77°F (43°C) temperature rise with a 0.5 GPM minimum. The unit weighs 66 lb in a 17 × 28 × 12 in cabinet with 1" NPT heating connections and 3/4" NPT DHW and gas connections, on 12 – 30 psi hydronic pressure (15–150 psi DHW).
The NCB-E generation shares several error-code numerals with the NCB-H line — E205, E218, E407, E421, E439, E517, E740, E777 and E782 among them — but codes were added and removed between generations, and the NCB-E installation manual carries no error table, so diagnosis for an NCB-E should follow the NCB-E service manual rather than the newer H-series literature.
Best suited to
- Owners of an existing NCB-E combi looking up its printed ratings
- Understanding the differences between the NCB-E generation and today's NCB-H
- Sourcing the correct generation of service literature for an older combi
Applicability and support
- Model number
- NCB-150E
- 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 Navien. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| Heating input, minimum | 12 MBH | Per the NCB-E Specification Sheet. |
| Heating input, maximum | 60 MBH | Per the NCB-E Specification Sheet. |
| Output | ||
| Heating capacity | 56 MBH | DOE test basis, per the NCB-E Specification Sheet. |
| Net AHRI water rating | 49 MBH | Net AHRI water rating based on a piping and pickup allowance of 1.15. |
| Efficiency | ||
| Efficiency (AFUE) | 95 % | AFUE per the NCB-E Specification Sheet. |
| Domestic hot water | ||
| DHW input, minimum | 12 MBH | 12,000 BTU/h. |
| DHW input, maximum | 120 MBH | 120,000 BTU/h. |
| DHW flow rate at 77°F (43°C) rise | 2.6 GPM | Per the NCB-E Specification Sheet; minimum DHW flow 0.5 GPM. |
| DHW connections | 3/4" NPT | DHW inlet and outlet, 3/4" NPT. |
| Venting and air | ||
| Venting | 2" or 3" PVC, CPVC, polypropylene; 2" or 3" special gas vent Type BH (Class III A/B/C) | Forced-draft direct vent per the official specifications. |
| Physical and connections | ||
| Weight | 66 lb | As printed in the official document. |
| Width | 17 in | |
| Height | 28 in | |
| Depth | 12 in | |
| Heating connections | 1" NPT | Supply and return. |
| Gas connection | 3/4" NPT | |
| Operating limits and other | ||
| Fuel | Natural gas or propane | Ratings are the same for natural gas models converted to propane use; field conversion is licensed gas work. |
| Hydronic water pressure | 12 – 30 psi | DHW side rated 15–150 psi. |
Alerts documented for this model
None documented yet.
Frequently asked questions
What are the ratings of the Navien NCB-150E?
The NCB-E specification sheet prints 12–60 MBH heating input, 56 MBH heating capacity, a 49 MBH net AHRI water rating and 95.0% AFUE, with DHW input of 12,000–120,000 BTU/h and 2.6 GPM at a 77°F rise.
Is the Navien NCB-150E still sold?
No. The NCB-E series is on Navien's discontinued-products list; the current Canadian combi lines are the NCB-H and NFC-H series. Official model pages and manuals remain online for existing owners.
Do NCB-E and NCB-H error codes match?
Only partly. Some codes are shared, but numerals were added and removed between generations and the same code can mean something different. Read each code against the NCB-E service manual (Ver 1.4, Oct 2015) for an NCB-E unit.
Questions about the Navien NCB-150E?
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 — NCB-150E product page (discontinued model downloads) · accessed September 9, 2026
- NCB-E Series Specification Sheet (EN) · accessed September 9, 2026
- NCB-E QuickFacts (EN) · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.