Navien NCB Boilers

Navien NCB Boiler Overview

The Navien NCB is a condensing gas combination boiler with an efficiency rating of 95.0% AFUE. It was named an Energy Star Most Efficient 2015 product and is available in three models — NCB-180, NCB-210, and NCB-240. It is designed to save space and occupies up to 80% less space than a traditional floor standing boiler with tank water heater. The NCB features dual corrosion-resistant stainless steel heat exchangers with a separate stainless steel flat plate heat exchanger for domestic hot water. The system can use 2″ PVC for venting up to 60 feet and can easily be converted from natural gas to propane operation. For situations with very high domestic hot water demands, the NCB can be cascaded with Navien’s NPE tankless water heaters.

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Consumer Reviews of Navien NCB


  • Very Satisfied
  • Somewhat Satisfied
  • Neutral
  • Somewhat Unsatisfied
  • Very Unsatisfied
  • #2 of 4 Navien Boiler
  • 32% of customers recommended

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Navien NCB Boiler Reviews

Showing 1-5 of 25 reviews


1.0 rating
Very Unsatisfied

The worst investment I’ve made! This machine is a lemon. Breaks down 2-3 per year. I’ve had this unit over 5 yrs and of course on year 5, it has gotten worse. I’m up to 7 calls this year and my luck, parts and labor are no longer covered.
Stay away from these units. My plumber has told me that he has 5-7 navien service calls per day. Units that other plumbers have installed.

Rick C.


1.0 rating
Very Unsatisfied

These units just don't last. After 3 years, it needs more than $ 1500 of service, plus defective parts replaced. My previous "conventional" the system lasted 30 years, with only minimal service every few years. This is absurd for such an expensive system.


Lowell, MA

"Navien Combi Heat and Hot Water"

1.0 rating
Very Unsatisfied

I purchased two Navien combi units for my house and In-Law apartment, an NCB-240 and NCB-180 in 2014. The first year the units operated ok except for winter temperatures in the teens in which the NCB-240 unit could not keep up with the heat demand. The second year and to date, 6/2019, I have spent $800 to $1000 in plumbing labor to replace Navien's "free" warranted parts. Any energy saving I anticipated is well past gone. Navien units are well less than junk status. I would never recommend any purchasing any of Navien's products for any reason even if received for free. Horrible quality.

Joel Williams

Billerica, MA

"Unacceptable service"

1.0 rating
Very Unsatisfied

I had the Navien Boiler installed on January 6, 2015. For the first three & a half years, it worked really well. Auchinachie Services Did an excellent job with the installation. However, since May 2018 the performance of the unit has gone downhill. For the month of May 2018, Auchinachie Services had to make at least 6 visits to correct the issue due to Navien's Micromanaging of warranty work. Unfortunately, Auchinachie Services Technicians were at the mercy of Navien Service. Navien service leaves much to be desired. Field personnel cannot replace faulty parts without Navien's approval. While they do overnight ship the necessary parts, it still takes 3 to 7 days from the time of the order to installation, due to the day of the week and the time of day order was placed. After three weeks with a malfunctioning boiler, I called Navien service to light a fire under them. I asked if they were waiting for a catastrophic failure of the unit before they would address the issue. I finally some action and the got problem resolved. On Feb 2, 2019, I experienced another problem with no Domestic Hot water. The technician has the three-way valve on the shelf but must get Navien's approval to replace.

Clarence Magee

Chenango Forks, NY

"Warranty problems"

1.0 rating
Very Unsatisfied

Please take these reviews seriously because they are from folks who are frustrated and have exhausted the recourse with the company. My problem started with a factory build manifold that leaked all during the night, the leak was from the factory solder, after spending an hour on the phone with Navien and sending photo's and there warranty claim form I was told that because I'm not a licensed plumber they will do nothing for me. This is a $187 part that failed 24 hrs after install! I would not recommend this company and personally recommend that you stick with a well known company name this company is not customer friendly. By the way I simply wanted a refund for the product (which I fixed part from leaking because it was fully installed)—- Beware Beware Beware!


New York

Other NCB Reviews

Online reviews of the NCB appear to be mixed. On, a post from a homeowner trying to choose between the NCB and a similar Lochinvar unit found most replies favoring the Lochinvar, although one member stated that he liked his NCB and had no problems with it. In another post on the site a member mentions that Navien has updated their boiler line three times in five years, and for that reason he cannot support the product.

NCB Warranty

The warranty for the Navien NCB boiler is comprised of the following:

  • 10-year heat exchanger warranty
  • 5-year parts and other components warranty
  • 1-year labor warranty

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