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 6-10 of 25 reviews

"Don't buy from Plumber. Use HVAC contractor"

5.0 rating
Very Satisfied

Over 10 years of installing these units and I have minimal problems. The customer service at Navien is the best. Parts are easily available, if the part is not in stock, it gets delivered by noon tomorrow from California. If your unit has problems, it is definitely from poor install, bad water or dirty power.



"Do NOT Buy This Product"

1.0 rating
Very Unsatisfied

Converted my house over to natural gas and had this unit installed by a certified Navien technician. The unit has been unreliable since day one. I never know from one day to the next if I'm going to have hot water. Can't count the number of times I have had to reset the unit. It works fine for a few days then shuts down. I can not leave my house for any extended period of time during the winter for fear the unit will shut down and freeze my pipes. I'm now without hot water and the unit needs a part. Only a certified Navien technician can communicate a problem to Navien or order parts. Can't get parts locally, only through Navien direct. It takes 3 days to get a part and forget weekends. No dealer carries Navien parts since distributors who sell the units are not allowed to stock parts. Customer serve his horrendous. They could care less about the customer. There should be a class action lawsuit against this company. Labor to install parts under warranty costs a fortune. Any savings accumulated through boiler efficiency is quickly consumed through labor costs. Do not I repeat do not buy this product. I'm stuck with it and there is nothing I can do to rectify the situation. I'm tempted to go back to my old reliable oil fired furnace.


Watertown, CT

"Defective Design!!!!"

1.0 rating
Very Unsatisfied

Someone please start a Class Action Lawsuit so I can recoup some of the money I am constantly dumping into this piece of garbage Unit. I have had the unit for 1.5 years and have changed out the Dual Ventri part 4x!!! Yes, the part broke 4 times!!!! About every 3 months the unit shuts down and starts making the same noise. Error light starts blinking with e-060 (Dual Ventri Error). There has to be a way to sue these people.

Anthony Calicchio

New Jersey

"Very happy"

5.0 rating
Very Satisfied

My original Navien boiler developed drip on condensation outlet bottom of heat exchanger, after talking to customer service was decided that I need replacement. Disconnected it drove to plumbing supply got free replacement, actually decided on newer model so payed the difference in price, installing new one toked about half hour, only difference is height of bracket that have to be moved 1/2', replacement works great and saves plenty on heating costs for four years now , replaced three way valve once and spark rod, that was expected since boiler is heating and making hot water for five family house 4500 sq feet . Anyone who has something wrong to say about this company head their boiler installed wrong, by someone who has no idea about modern hydroponics, or connected to heating system that is not compatible to work with condensing modern heating boiler or just have unreasonable expectations. Everything needs maintenance. If your Navien boiler don't condensate fool time after being properly set up you should stay with your old cast iron clunker.


New York

"Navien Combi boiler"

5.0 rating
Very Satisfied

I have installed over 250 of these Navien combi boilers since Sandy. I have one in my home. Navien makes improvements every year to these boilers. There has been some issues yes. I have made repairs on a number of these boilers but like I said the older ch models have a tendency to leak from the heat exchanger in which case if you call Navien and follow their protocol they will warranty the unit with the newer model ncb-e series. Out of all wall hung boilers I have seen since Sandy these in my personal opinion happen to be the best. Yes they are sensitive so water filtration systems may be needed and yes they do need to be flushed out every 18-24 months but if you have a raised home on a water prone area or you lack space the Navien ncb 240e series is the best around. Most problems occur because of poor installations and lack of maintenance. But for the most part the boiler is solid. Now is it going to last 30 years? I doubt it but I'm hoping to get a solid 15 years from mine and if installed correctly swapping the units out will take minimal effort. If anyone looking for Navien installs or service and they live on Long Island in the Long Beach area call Seaman Plumbing 516.431.7473 for proper install and service

Jim seaman

Nassau county

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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