The Navien NHB is a condensing gas boiler with an efficiency rating of 95.0% AFUE. It was named an Energy Star Most Efficient 2016 product and is available in four models: NHB-55, NHB-80, NHB-110, and NHB-150. The NHB is a wall-hung boiler, designed to occupy far less space than a traditional floor-standing boiler. It can be vented with 2" and 3" PVC, CPVC and approved polypropylene, with venting up to 60 feet using 2" PVC, and up to 16 units of the two largest models, the 110 and 150, can be cascaded. An optional NaviLink control allows remote temperature control and monitoring.
"Good design, no frequent exchanger cleaning needed"
Bought a used one, installed last winter and worked excellently. Believe all defective ones were caused by installation – it's nothing to do with the year of experience in the industry but a smart and responsible one is essential. I installed by myself and I am not a licensed. When trying to do yearly exchanger cleaning and found to my surprise – the burner is located at the bottom center of the upright stand exchange coils, no residual will possibly fall to the coils. Great design! Yes, it's a little bit noisy if not installed well. I set the temp to a lower level and the fan will run at a slower speed. The best way is to install it on a concrete/foundation wall and does not let it touch any wood structure. Use some rubber to absorb some shock should be also helpful.
Have installed several units in the past few years, mostly nhb-150 with indirect Dhw. Quiet unit and reliable. When we had questions or any problems, the help support was amazing. We had to replace a front board because it had cosmetic damage, we received the part 48 hours later filled the form and had our labor paid by Navien. If installed properly, by qualified technicians, it will run great. Combi unit on the other hand… Well it's a combi, it's compact therefore service will be longer and it will take some time to have dhw plus no one should use hot water when someone is showering, thanks to reacting time. Honestly, if available space is an issue get a combi otherwise just don'T. Space heating with an indirect tank is the way to go.
I have installed over 150 boilers over the past 5 years and less than 1% I have to go back to repair; also Navien has a full package with 100% of parts that only trained contractors get when they are certified. So if you hire a contractor that doesn't know how to install or repair these boilers, you didn't ask enough questions and were trying to save some money. Now I have been call to fix over 50 Navien boilers last year because they hire someone that just was in it to make some money and don't know how to troubleshoot them. 95% of them are wrongly installed. I had serviced all models and brands and they all will give you problems at some point in life. The only equipment out there that never gave any problem went out of business 60 years ago cause they couldn't sell any parts. Navien 110 great heater. 2 years no problems. Bill Bowe.
Ours is the 2015 model. It kicks on and is so loud it sounds like an automobile with a big engine is going to drive through the wall. It scares the dog. The humming is very annoying.
"Navien Combi is Cheap"
My installer is an experienced HVAC / Plumbing contractor. He has never dealt with such poor support from a manufacturer in his 25 years. After this disaster he will never put a Navien in again. No support from the factory, just change parts and hope for the best. 3 way valve, blower motor and now the heat exchanger. I'm not out $100 it's thousands. I should have done my homework or listened to the installer. Stick with the brands with a history; WM, Triangle Tube etc. Good Luck to the rest of you Mr Edwards Wisconsin
A homeowner on heatinghelp.com asked if the NHB was a good unit and was told by one professional that it's okay but there are better units available. There was a long discussion on the same post between professionals regarding how long it takes to get parts for Navien boilers. On terrylove.com, a homeowner asked for opinions regarding the NHB and a Dunkirk boiler and received a couple of replies from professionals who preferred the NHB.
The warranty for the Navien NHB boiler is comprised of the following:
15-year heat exchanger warranty
5-year parts and other components warranty
1-year labor warranty
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