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 11-15 of 25 reviews

"Really hate this product"

1.0 rating
Very Unsatisfied

I am reading these reviews and it is like I wrote them. Did a conversion 3.5 years ago and now the unit is rotting on the wall. The condensation has caused rust and crud all over. They keep sending the wrong parts and there is no one to talk to except low level staff who have no authority to make decisions. I am now entering day 8 with no heat or hot water with no relief in sight for 2 more days and that is only if what they are sending works. Time for a class action lawsuit?


Northern NJ

"It�s all about your contractor."

5.0 rating
Very Satisfied

You know. I have been reading these reviews and almost all of the negative reviews about the units seem to be about improper installations or excessive labour fees to repair the unit or waiting for parts. We have been Navien service specialists for over 10 years now and have had great success with Jensen units. If your contractor was an nss, he would have a repair kit with all the necessary parts of your unit was to fail and the replace his stock when the parts arrive from Navien. Also, all manufactures have similar warfanties. One year labour. If parts are replaced or the unit is replaced, they will carry the balance of the original warranty. Industry policy. And lastly, have your unit serviced regularly including flushing and descaling as preventative maintenance. So before you hire a contractor to replace your boiler with any brand, do you homework on the contractor as well as the unit. Take responsibility for your choice of contractor.


Vancouver BC Canada


5.0 rating
Very Satisfied

First, I failed to do research in my local area for recommendations and simply went with Home Depot's heating contractor to replace a 50 year old combination boiler/dhw heater. To my surprise, I was recommended the Navien combi unit and already impressed in two months of use into the first winter. I've already seen less gas use since a boiler isn't maintaining 40 gallons of hot water. Hot water is as expected and more reliable than wondering when someone uses the washer or washing dishes while showering. While I've followed up and read many more negative reviews of Navien products, I can state that my plumber came licensed and trained in Navien installations. This may be the main reason for mine and many others with great results, installation by qualified plumbers trained by Navien. I watched the installation and observed in detail, later finding out that installation used all the options for a complete setup to include future maintenance with extra valves to allow maintenance when needed – flushing the system of buildup and occasional water filter cleaning. I maintained my old boiler so it wasn't difficult to learn tankless technology and different issues if they pop up. So far, heating is great for the three zone hydronic system in a two family home and hot water when needed. My only problem is finding out the specific failures with other Naviens with disappointed home owners. With licensed plumbers and Navien trained, I cannot see where these products fail. Tankless is proven elsewhere in the world with each product having specific issues no different from oil or gas boilers. Perhaps the so called plumbers and failed units aren't honest about their unfamiliarity with them and the nuances that can make tankless units act poorly. Even more issues may plague diyers assuming they know enough when they aren't considering everything that makes a licensed plumber knowledgeable. During the estimate before deciding on tanked or tankless, the plumber was extremely open and discussed everything I brought up, a conversation lasting close to an hour or so. Hopefully, I made the right decision with the right plumbing company and will see years of reliable service.

Fred Dryer

Queens, NY

"Piece of crap"

1.0 rating
Very Unsatisfied

Installed the unit 3 years ago in my cottage. Constant problems with the boiler shutting down especially in cold weather. Have had 2 freezes resulting in burst pipes. Have spent thousands on labour and new parts. Even spent money on a wireless alarm. Now there's problems with the hot water. Needs a new part which won't be here for 2 days. Meanwhile no heat and hot water in winter. Definitely cutting My losses and replacing the whole thing. Don't waste your money on this product. This company should be out of business and installera who install a piece of junk like this should be sued.

Lynn T

North Bay, Ontario, Canada


1.0 rating
Very Unsatisfied

I purchased a ncb240e Combi for a client. It worked for about one week when the problems started. First the pump failed. Navien told my tech that particular pump had been upgraded due to many failures. We waited for the new pump and installed it. 2 days later another call back. This time the 3 way valve failed. We waited and installed when arrived. It worked sporadically for the next couple of months and then quit altogether. I purchased and installed a new boiler and have only had one minor problem. My wholesaler did nothing. Navien did less. I was told by some little at Navien that because I took the original off the wall it was not their problem. Hard lesson learned! Do yourself a favour and never purchase a Navien product, your life will be so much better.


Calgary Alberta, Canada

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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