Navien Tankless Water Heaters Review

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Navien isn’t exactly a household name, but it should be. This company is at the forefront of tankless water heater and boiler technology. Owning a Navien tankless water heater means lower bills and a much smaller carbon footprint.

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They also have a higher compatibility with your existing water system and longer-lasting parts so you can save money from the moment you purchase a unit. It’s time to get to know one of the best tankless water heater companies and why they’re a secret you’ll want to share.

The History of KD Navien Co., Limited

KyungDong Navien is a younger company, having been founded in 1978. Ten years later, it began making an impact by being the first Asia-based company to develop a high efficiency condensing boiler that was environmentally friendly. The company’s reputation grew as they achieved high-level certifications across several continents.

Over the years, KD Navien has expanded its products to include HVAC and numerous home systems. All of these share a focus on greener living and higher efficiency. Today, the company has two branches in Asia, as well as one each in Europe, Australia, North America, and South America.

As they are a younger company, their name isn’t as well-known as Rinnai, Rheem, or even Noritz, but KD Navien has worked hard to excel these older companies in both efficiency and environmentalism.

Tankless Water Heaters

Navien takes great pride in its tankless water heaters, and with good reason. These heaters have some of the highest efficiency ratings on the market and are also among the greenest. Two tankless lines are available, the NPE-A and NPE-S.

Common Features

All Navien tankless water heaters hold to a high standard, providing both ENERGY STAR and LEED certifications. They also use condensing technology to reduce your water bill and provide on-demand hot water with no wait time.

The controls are easy to use and Navien water heaters can both common vent up to 8 units and cascade up to 16 units, making them perfect for apartment complexes as well as single family homes.

NPE-S Line

The standard line is quite impressive on its own, and has many design features geared towards reducing installation costs. This higher affordability doesn’t reduce the level of quality, however. An outstanding .97 UEF rating makes this one of the most efficient lines on the market, and many of the components are designed to require less maintenance than non-condensing models.


The advanced line provides more quality than just about any other tankless heater on the market. Starting with a Uniform Energy Factor (UEF) of up to .96 and low NOx ratings, these units include ComfortFlow recirculation technology to eliminate cold periods.

To provide additional savings, the recirculation pump can be deactivated. These heaters can provide up to three LEED points and will help reduce your home’s HERS index score. The advanced series can also be Wi-Fi enabled with the NaviLink add-on.

Best Navien Tankless Water Heaters

ModelGallons/MinuteMax BTUsEnergy FactorNotes
NPE-240A11.2 GPM199,9000.96recirculation system
NPE-240S11.2 GPM199,9000.97low operating costs
NPE-210A10.1 GPM180,0000.96recirculation system

Navien Tankless Water Heater Parts

When maintenance time rolls around, your Navien water heater shouldn’t be passed over. As with all tankless heaters, corrosion is less of an issue than with normal tanks, but some parts will wear out over time.

Valves, vent parts, and filters will all degrade over time. Electronic parts, such as the control panel, may also need maintenance once every few years to replace any loose or damaged components. When issues arise, pay attention to any error codes from your Navien control panel to help with troubleshooting.


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Where to Buy Navien Tankless Water Heaters

Navien water heaters are currently not available at big box home improvement stores such as Home Depot and Lowes. You’ll instead find Navien models on and smaller online retailers as well as local distributors.

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  1. I don’t want to be negative about my Navien tank from the begining so I will let you be the judge if I can be negative or not…
    -I paid close to 3000$ for my tankless hot water tank – 2 to 3 times more than a conventional gas heated, power vented water tank. I was willing to pay the price and expected equivalent longevity to a conventional gas heated water tank.
    – it lasted 8 years before what appeared to be a flow sensor break down. A conventional hotwater tank lasts between 15-20 years
    – 400$ for a new flow sensor and labour did not fix the problem, it was determined that it was the mother board
    -700$ plus tax, plus labour would have the tankless H20 heater online again
    -total 1100$ equivalent to a brand new gas heated, power vented water tank
    -Navien has proprietorship of the parts in the water tank so parts need to be ordered from Navien – time delays and higher than normal cost for replacement parts
    – Navien technicians on their support line will only tell the homeowner to ‘switch the power off, wait 30 secs, then turn it on”. They won’t deal with anyone other than a licensed technician.
    – consequently the Navien tank got recycled for copper and a new gas heated, power vented hotH2O tank was installed

    I don’t want to limit my bashing to Navien, but to all tankless water tanks and their respective companies. They are over priced, the quality is not comparable, and they have a monopoly on their parts. Sure, I enjoyed the tankless water tank for 2 reasons: 1) the practicality of having the water tank on a timer and 2) the psychological advantage of saving gas because gas is not burned on a regular basis to constantly heat a large tank of water. However, the enjoyment was short lived and the repairs expensive when compared to a conventional gas heated water tank. Upon reflection, I would never spend 2000$ (the difference in price between a conventional tank and a tankless unit) on gas used to heat water in a conventional tank over an 8year period.

    Am I allowed to be negative?

  2. I have had 3 of these installed in my apartments. They are both the hot water heater and provide floorboard hot water heat. Each cost more than $4,000 to install. I have had nothing but problems with tenants complaining. The biggest problem is the amount of water flow needed to kick on the hot water is HIGH. Forget using a low-flow shower head or anything else. All low flow restrictors have to removed from faucets and shower heads in order to have enough umph to get the hot water tank to kick on. I complained about this to my plumber, and he confessed that he often drilled out customers’ shower heads in order to make the necessary flow happen. I will now be drilling out all my tenants’ shower heads and faucets. What that means, being on city water/sewer, is my water bill will go up considerably. Also, it already goes up with these units as it does take (wasted) water to flow through the unit to kick it on. So you choose – a higher water bill and frustration to save a few dollars on my natural gas bill. It’s not a wise trade off.

    • I do agree that one of the hardest things to get used to with tankless models is the minimum flow rate for the water heater to kick on. This makes trying to save on water usage difficult.

  3. I do agree these can be frustrating. I own several Navian systems including the latest combo-boiler. They are efficient and space saving. They can be repaired yourself if you have the interest or ability. The parts are usually inexpensive. It’s the expertise that’s in short supply. Flow sensor is $25 and takes 15-20 min to install. The lifetime of the earlier models was around 7 years. I’m getting ready to replace a 9 year old one.

  4. A conventional hot water tank lasts 15-20 years?? Maybe 20-40 years ago… not now! Lucky to get a decade out of one. Everything is built to die.. hot water tanks, furnaces, washers, dryers…

    It’s the world we live in now.

  5. I have had a Navien Combi for 4 years. Spent $2,750 repairing it and now it’s rusted out internally, leaking and on the brink of completely breaking. Worst combi boiler ever.

  6. I replaced my furnace and hot water tank for a Navien Combi. Biggest piece of crap I can recall purchasing. Warranty covers replacement parts, provided you are a licensed technician making the repair. Unit is only two years old. Lost heat during the winter as an electronic relay directed the system that unit pressure was too high and redirected water flow to pressure relief valve causing a flood in basement. $650 plumbers fee to have Navien send me a valve which took me 5 minutes to repair. 2 months later, now I have no hot water. Technician needs to speak with licensed contractor to verify that mother board is likely the problem. I had conversation about this piece of crap boiler with a friend today who had similar and many more problems with his two year unit. He has since junked his. Think hard about a purchase if you are considering one.

    • Hi David.. are thinking that another brand would be better? I need an electric water heater..
      To me, it sounds like this brand only lasts for about 4-6 years, so I’m thinking we should purchase the lesser cost and just replace them..

  7. Recently purchased new home with Navien NPE-2408 unit. It takes quite a lot of running water before feeling heated…curious as to how much others water bill increased percentage wise. Seems I’m saving on a cheap expendable gas in lieu of ever increasingly expensive water which will no doubt have a usage ban at some point in a hot/dry summer.

  8. I’ve had two Navien tankless water heaters in 9 years for my home. The first one had multiple problems, needing replacement after 5 years. I was gullible enough to have it replaced with a newer model offered with a small discount. After 4 years, this unit has sprung internal leaks, corroding the interior. These units are expensive. In principle, you’re supposed to make up for the high cost with terrific savings on gas usage. If the units were of sound quality and would last at least 10 years, you would save. But they aren’t. I’m beyond fed up and am replacing my Navien with a plain vanilla, energy-saving tank unit built in America.

    My advice: steer clear of tankless units, Navien in particular.

    • Yes, James.. that’s what I’m thinking.. purchase a good energy saver and just plan on replacing them.. You sure could buy quite a few of the other ones before you would reach $4,000.00.. I thin I just answered my question..

  9. For you who have had trouble receiving hot water when using a low flow, do any of you have a water recirculating system with your Navien system? Are you systems under the sink or a point of use or are they whole house/apartment systems? A plumber has recommended I install a tankless and recommended this brand.

  10. to richie. .. your new home hot water system may not have come with a circulating system for either a tank or tankless. so it may not be the tankless problem. some tankless come with a built in circ pump. or a inexpensive one can be installed either under kit sink or in bathroom if you have a 120vac connection which electrician can install. not sure if there is a battery op model. simple connections and timer to provide hot at times of use. try to keep water temps around 120 . have plumber check to see if there is a circ pipe near the water htr location,, half inch is very adequate and 1/35 hp is also adequate. used in hotels and apt buildings. simple.

  11. We just moved into a brand new home with two new Navien 240S tankless water heaters. It takes approximately 50 seconds for the water to get hot coming out of the faucet. I checked the water line length and they are all short runs so I thought the water heaters may be malfunctioning. I spoke with the local Navien rep and he was surprised and said the Navien hot water heaters should get water up to temp in about 10 seconds and then an additional period to transport the hot water to the receptacle. He came to my house and we both stood at the water heater and timed how long it took for the incoming water to get up to the desired 125 degree outgoing temp. Forty seconds! At first he thought something might be wrong so he called the in house experts at Navien. They said that is how it is supposed to be! The rep said the factory had been saying 10 seconds to him for years and everyone says ten seconds. But when you actually put them to the question the answer is 40 seconds. How can that be? The wait for hot water is so long (50 seconds total) that most guests assume that there is a problem with the water heater and do not wait. No one is willing to wait 50 seconds to wash their hands so they just wash with cold water or go without. (Wow!) The Navien rep said the company would not do anything to help me nor would they even give me a discount on the purchase of the 240A which actually has a storage tank to address the delay. Don’t be fooled. Navien hot water heaters produce endless hot water but you really have to wait for it.

    • Dear Customer, we are very sorry to hear about your disappointment with your Navien purchase. Navien cannot control how long it takes for hot water to move from the unit to the fixture as that depends on the distance between the Navien and the fixture. Also, the unit does not have a set amount of time it can heat water up within. There are numerous variables that come into play such as your incoming ground water temperatures, the temperature your unit is set to, and how recently the unit was last run. Our “A” models can provide hot water much faster when a recirculation line is ran. Other things such as timers also help with faster hot water in peak use times such as for morning showers.

      Navien wants to make sure the right information is being put out into the field. If you would please provide some additional information, we can address the issue with the rep and trainer. Please email the following info to
      · Your unit serial number (15-16 digits on outside right of unit)
      · The rep’s name, company, and any contact information you have
      · If the rep mentioned who said this “10 second” rule, please provide that as well

      Thank you. Navien

    • I was just reading about them and came here. They hook up to 1/2 inch pipes and I think it said the max. length to travel should be 24 feet, if I recall. I remember thinking 24 feet and a small diameter pipe doesn’t sound very good to me. From the reviews, I guess I was correct.

  12. 4 years ago had Navien NCB240 installed. It has been absolutely nightmare. I must have already spent $3000 on repair (labour + parts). It is absolutely garbage product. I am to a point that I have requested my plumber to replace the piece of crap. It is going to cost me over $5000 to replace it. But on the long run, I think that will be cheaper.

    Do not ever buy Navien products.

    FYI. In the past I had communication with Keneneth Tindal, Amanda Montiel.

    • Dear Mr. Bhavsar,

      I’m sorry to hear you’re still having problems with the unit. The correspondence between you and Kenny/Amanda was found from back on February 2nd, 2017. We asked for a water sample to be submitted for testing, but I don’t show the requested sample was ever received from you. This would still be the next step Navien needs you to take in order to take a look into this further. Please find the instructions for submitting these to Navien here:

      Thank you.

  13. I am a Navien installer and can tell you that I have installed all kinds of other units and find that Navien is the best. I install approximately 10 units per month for customers and they love them. I have had “0” problems with them and the re-circulation feature is the best and my customers love it. I think that maybe your sales rep from the installing company doesn’t know how to install or doesn’t ave any idea how the systems work.

    As far as a conventional tank is concerned, the average life expectancy is only 6-8 years and they do not compare to Navien tankless. Water condition, hardness and quality play a large part in how any system works and routine maintenance of the unit as recommended by the manufacturer is very important. Re-circulation with a comfort valve is a huge plus for those that don’t have a dedicated re-circ line in their system. The “A” series has the re-circulation pump and the “S” series does not. Make sure you inquire about the system being installed and it is the right one for your application.

  14. My plumbing company was just here for the 8th time to attempt to fix my Navien tankless water heater. Listening to the poor service techs trying to get help from Navien support is ridiculous. Navien techs just read a script and go over the same thing every time and nothing gets fixed. Besides making intermittent loud noises my gas usage is now consistently HIGHER than when this “high efficiency” unit was installed. Why don’t water heaters have a lemon law?

  15. I have spent $2000 in last nine months. I had Navien installer and certified technician came to fix this year for 9 times in 9 months. I had no hot water for almost two months this summer. I had no heating for couple weeks last winter.

    My plumber installed Navien Model CH-240 unit 5 years ago. I converted from oil to natural gas and spent $12,000. My older oil unit never gave any issues for 20 years.

    Following are repairs in last 9 months with $2000 cost plus no heat or hot water today.

    Error code 003E, Heater Flame Rod fix 2 times
    Heater 3 Way Valve, Oring fixed
    Error code 015E
    Flame Rod, Ignition Transformer, Leak Fix, PCB (Motherboard) fixed
    Error code 002E

    Why should I go through cost, mental stress, and no heat and hot water?

    • Dear Customer, we are sorry to hear that you are experiencing issues with your unit. Would you please email your unit serial number and contact info to so that we may look further into this issue? Thank you.

    • Dear Customer, we are sorry to hear that you are experiencing issues with your unit. Would you please email your unit serial number and contact info to so that we may look further into this issue? Thank you.

  16. I moved into a brand new home with a brand new Navien almost four years ago. Right from the beginning, the heater would go out and have to be reset multiple times a day. Called for service at least 10 times over the past four years – spending close to $1800 in service calls. Each time, the technicians called Navien support and had them on the phone. Every time, Navien would blame another part. The heat went out again on 12/21/19 – service was called – Navien was called and again was told to switch out several parts. However, the parts did not come in until 12/17/19. I had a house full of company with no heat or hot water. Very poor system – very poor customer service. I have seen dozens of reviews stating the same problem. They just prolong the agony by blaming multiple faulty parts instead of admitting that the system is a lemon. Would NEVER recommend them. Had they resolved the problem promtly it would be a different story – but it is now four winters with this going on and they are still switching out parts. I am thinking they will keep switching out parts until the warranty is over. Horrible company to deal with.

  17. Our system is only 3 years old. The heat exchange unit of our tankless NPE 240-A needs to be replaced ( after water was leaking all over our cellar floor, one of the reasons we bought a tankless was we were told we wouldn’t have to worry about a flooded cellar!)
    Yes, its covered by the warranty, but no one tells you that although the parts of unit are covered, you still have to pay for the labor….after paying over $200 just to diagnose the problem, we are now looking at $300 – $400 to have the ‘warranty’ part installed!! So disgusted and going back to the old fashioned ‘tank’ system!

    • I don’t know this, and you may not either, but my unit inconsistently backfires due to failed/delayed ignition attempts. It’s less than a year old. I only notice it because it’s near where I am all day. No one has been able to figure out how to correct it. I’d imagine that if I never noticed it like most people probably wouldn’t with something that is in the basement or out of normal earshot, my heat exchanger probably would’ve cracked within 3 years as well. I don’t think these units are good for everyone’s situation, but the problem is, is that it doesn’t seem like anyone can tell whether or not it will work correct until it’s installed.

  18. I too had The NPE 240-A installed at the recommendation of my plumber less than a year ago. It seemed to work alright for a few months but I started noticing it backfiring due to what I’ve been told could be an intermittent delayed ignition. So I’ve had the venting changed around twice now and had 3 “navien certified” local plumbers look at it to no avail. I was then plagued by daily (sometimes multiple times in the day) ignition failures after a couple more months. I’ve spent an additional $1000 so far on top of the $3500 it cost to install. I’m having the last plumber, who seemed the most knowledgeable so far come back for one final attempt. Depending on what he and Navien come up with I will likely just tell him to forget it and put in a tank unit again. I still am not sure if it’s the technology of tankless being too sensitive, the manufacturer of Navien being low quality or the lack of a local service person who has the right knowledge to get this working. I’m currently leaving the unit off and unplugged for fear of my safety and sanity of a backfiring gas appliance and only turning it on to shower and wash dishes. I’m hoping to have this resolved this week. I wish I hadn’t trusted the installer’s recommendation and did some more research. You live, you learn but I fear I’m out over $4500 dollars at this point.

    • Hello Jim, we are very sorry to hear that you have been experiencing issues with your unit. Would you please email your unit serial number and contact info to so that we may look further into this issue? Thank you.

  19. Wow. I wish I had found this site before I replaced my tank and installed an NPE-S heater today. I haven’t timed the wait for hot water, but it takes about 1.5 gallons to reach a usable temperature. This is and will continue to be a problem in long term drought conditions here in California.
    I’ll probably need to have my brand new Navien heater replaced next week by a tank.
    Like they say, a good education is expensive.

    • Hello Ed,

      Thank you for reaching out to us. We are very sorry to hear that you have been experiencing issues with your unit. We recommend that your service provider call into our tech support at 1-800-519-8794 option 2 so that we can have our team diagnose the issue and provide a solution. Our tech support is available Mon-Fri from 8am – 9pm EST and Sat-Sun from 8am – 8pm EST. Thanks!

  20. We just moved into a home where a Navien tank-less hot water heater was installed less than two years ago. The noise from this unit in the bedroom closest to it was so loud no one could sleep there if someone were to take a shower or a bath. The people that installed it pretty much said that’s the way it is. So my advice, for the cost I never would put this unit in for this reason and after reading the other reviews it just substantiates why I would never put one in. Meanwhile for the cost which is not a savings by all means we have to put up with it. Very disappointed.

  21. Thank you for reaching out to us. We are very sorry to hear that you have been experiencing issues with your unit. Could you please email your unit serial number and contact info to so that we can have someone from our tech support team review your case and reach out to you? Thank you.

  22. I have 2 Navien heaters installed in my home in New York City about 5 years ago, each cost about $2500.00 including installation. After the first year of trouble free service I am spending about $800.00 to $1200.00 annually for repairs, not too many technical service is available for repairs, if one is located he needs $150.00 before he would he comes over. Navien do give any technical support over the phone to the home owner. After the first year I emailed to ask how long is the warranty and I never gotten any response . Gary


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