They don't stand behind their products. My friend got a lemon and they live in New England. It's freezing there and they have no hot water! No heat! They are dragging their feet about coming to take care of this piss poor boiler. Don't expect good customer service because it doesn't exist with Navien

We installed this over the holidays 2018-2019 for our commercial tenant. Poor instruction manual left out that you need to use a T stat that comes with a battery. After a long install period since we completely replaced 2 old natural draft boilers and one water heater with this system. After completion, it would not fire up. Called tech support and the only thing they were interested in was that I did not run a heating company so why did I install it? It was between the holidays, no one was available for under $25,000.00, oh yea and I have a HVAC degree, the guy who did the soldering is a welder, the wiring guy is a retired fireman and licensed electrician. But the focus wants on the bad product it was on me according to tech support. We got a local so-called Navian expert after some searching, and he replaced the gas valve after they overnight the part. It still didn't work. Then they replaced the board. It worked but we later found it wouldn't shut off when the weather got warmer. We lost thousands on lost rent and the "local expert's" repairs. They did not warranty any of our losses, I guess we should be grateful they didn't charge us for the parts that were faulty from the factory. Navien supposedly told our hired expert that " they were very upset about the nfb 200 boilers being shipped in such poor condition" as if this was supposed to make us feel better. Oh yea, and the local expert took hours to discover that this model must use a T stat with its own battery, that's why it didn't shut off. More money in repairs, and research time for the local expert to figure out on my dime. It is my first and last time investing in Navian products.

Frozen for the holidays. Visiting my family over the holidays in Winter. 11 days no heat. It took over a week just to get a small part and that was faulty. Another week without heat until the right part arrived. Don't buy one.

Replaced our reliable 60 year old oil burner with Navien- gas and hot water system. Has not worked right since the beginning. Now have it 18 mos and it's failed completely. Every time it needs a part- it must be ordered from the company and shipped to receive the next day which is ridiculous. There should be a way techs and homeowners have access to parts as needed. Tired of cold showers. Should've kept my old furnace and hot water heater. Completely unsatisfied and would not recommend.

The unit is very hard to install, and their dealer network is very immature. The unit broke down in the middle of a Chicago winter, but none of their dealers carried the 3-way valve. Navien can't ship out a part on Saturdays, even in winter. When finally, they could ship a part on Monday, they can't expedite the shipping and can only ship standard- overnight. Calling them doesn't help – they just shrug their shoulders and that too quite rudely. We are without heat for several days because they can't get after-sales service to do any better. The unit is less than 5 years old. This after, it took them 3-4 months to get the installation right in the first place.