Best Navien Tankless Water Heater Reviews

NOTE:  Navien has ceased selling their units on

Let's take a look at some of the best Navien tankless water heaters on the market.

I can't even count how many times I've been asked about "the best" tankless water heater. To the frustration of my customers, it's a hard question to answer. How do you define best? What functions and features do you prioritize over others? Is price the deciding factor for you, or are you more concerned with power, performance, flow rate, energy efficiency or long-term value?

The bad news is that there isn't a single water heater that will suit everyone. The good news is that there is one brand that you can choose from if you're looking for high-quality, high-powered tankless water heaters.

About Navien

I could go into the history of the brand, but I doubt you care about that. Here's what you need to know about Navien: They sell some of the most powerful tankless water heaters on the market.

While other companies are puttering around with units that only generate 2-3 gallons per minute (GPM), Navien creates products that offer 10 GPM or more.

While other companies are warning their buyers about the fumes and gases that come with natural gas and propane water heaters, Navien revolutionizes the industry and creates special low-NOx condensing technology to negate the risk.

All in all, if you're looking for the brand that sets the curve, Navien is it.

Top 4 Navien Tankless Water Heaters Reviewed

So which Navien units are the best of the best? I'm glad you asked. I've put together a list of Navien tankless water heater reviews, and I believe they can help you decide which model is right for you. Let's go!

1. Navien NPE-240A Premium Condensing

The NPE-240A Premium Condensing offers a staggering 11.2 GPM, more than enough for simultaneous sinks and showers and triple what other tankless water heaters can provide.

It does need 199,999 BTUs, an energy requirement that's rather high, but rest assured that the unit boasts a 97 percent energy efficiency regardless.

In terms of size, the NPE-240A Premium Condensing clocks in at 17.3 x 13.2 x 27.4 inches and 82 pounds, and it can be installed both indoors and outdoors depending on your wishes. 


As a whole-house unit, the NPE-240A Premium Condensing will serve multiple bathrooms from a single location. You can also link multiple units together to provide hot water for high-demand or large-area locations such as schools, hospitals and commercial buildings. Don't worry about installation sites, either; though it's a natural gas unit that requires venting, it can be installed indoors and outdoors because of its special low-NOx condensing technology.

Heat Output and Flow

As previously mentioned, the NPE-240A Premium Condensing boasts 11.2 GPM, a remarkable number that's almost unprecedented in tankless water heaters. You can expect your range to be from 98°F - 140°F in terms of water temperature. You can also change your display to give Celsius numbers if you prefer; the unit comes with a clear digital interface and easy-to-use buttons. 


This unit may have a special internal condensing system, but don't let that fool you into thinking installation will be easy. It still requires special vents to prevent fume build-up, especially if you're installing the NPE-240A Premium Condensing indoors.

If you have any questions about what to do, contact Navien technicians.


-Powerful whole-house unit provides 11.2 GPM
-Internal condensing system takes care of the worst of the fumes
-Comes with many special features


-Can require up to 199,999 BTUs
-Installation comes with venting needs

2. Navien NPE-240-A

This unit is very much like the one above, but it comes with the notable difference that it doesn't use a low-NOx internal combustion system.

This makes the NPE-240-A both bigger and bulkier (13.2 x 17.3 x 27.4 inches and 92 pounds) than its counterparts, and you'll need special equipment if you want to install it indoors. The good news is that it still comes with an 11.2 GPM flow rate, so if you're looking for power, this is another product that will give you what you want. 


Without the special combustion system of the unit above, the NPE-240-A lags slightly behind in terms of energy efficiency and ease of installation. Never fret, however; it's still an extremely powerful unit that can serve four or more bathrooms at once. Fill up the tub; do a load of laundry; run the dishwasher a few times. The NPE-240-A can handle it all. 

Heat Output and Flow

The NPE-240-A offers the same heat and pressure as the NPE-240-A Premium Condensing, so you'll enjoy 11.2 GPM and a temperature range from 98°F - 140°F. Something new, however, is that the purchase of a NPE-240-A comes with a buffer tank and recirculation pump right in the box. It may not have internal condensing power, but all Navien products want you to be safe.


This is the product that comes with a buffer tank and recirculation pump included with every purchase, and it can also be hooked up to your home's HVAC system with your existing ground line, so it's actually relatively simple to install.

Again, however, you might want to let trained technicians handle it if you're nervous. You can also check out installation guidelines on Amazon.


-Can be converted between natural gas and propane
-Buffer tank prevents cold water "sandwiches"
-Utilizes your existing gas line


-Heavy, hard-to-maneuver unit
-Lacks the internal condensing properties of other Navien products
-On the upper tier of affordability

3. Navien NPE-180A Premium Condensing

Offering 8.4 GPM at 120 volts, the NPE-180A Premium Condensing isn't the strongest tankless water heater on the market, but it's far from the weakest either.

It's a nice, study model at 17.3 x 11.4 x 27.4 inches and 75.5 pounds, and it's wall-mounted to boot, so you can enjoy the heft of a powerful unit without sacrificing any floor space for it.

If you want a natural gas model that will get the job done, try putting the NPE-180A Premium Condensing on your shortlist.


We're back to the condensing units!

The NPE-180A Premium Condensing more than lives up to its promises of energy efficiency; as a certified Energy Star product with all the low-NOx features you've come to expect from Navien, the NPE-180A Premium Condensing will save you plenty of money on your energy bill. It's a whole-house unit, too, so you'll be eco-friendly without sacrificing any of your daily hot water needs. 

Heat Output and Flow

Most Navien products offer a temperature range of 98°F - 140°F, so it should come as no surprise that the NPE-180A Premium Condensing is the same. While its flow rate (8.4 GPM) is slightly lacking when compared to other products from the Navien line, it's still more than enough for what the industry calls "simultaneous usage."

All things considered, it's a powerful and customizable unit that deserves a look.


With two stainless steel heat exchangers and internal preheating technology, you might think that the NPE-180A Premium Condensing would be a nightmare to install. You'd be wrong! It uses your existing 1/2" gas line and is also fully convertible between natural gas and propane. It's designed to be easy to use and easy to install. 


-Low-NOx system breaks down harmful fumes before they can escape the unit
-Can be hooked up to other units for commercial use
-Good balance of power and precision


-Heavy box can be difficult to haul and install
-Energy efficiency is lacking when compared to other Navien products
-Not the most affordable on the market

4. Navien NPE-210A Premium Condensing

Boasting a flow rate of 10.1 GPM, the NPE-210A Premium Condensing is more than a match for others on this list of Navien tankless water heater reviews. It's powered by 120 volts/200 watts; it has all the condensing properties you'd expect from an indoor/outdoor unit; it comes with a 15-year warranty that will protect you long after the shine has worn off the box.


There are a lot of reasons I recommend the NPE-210A Premium Condensing to my customers, but the biggest one is that it's just plain convenient.

It offers a good flow rate and requires only minimal energy in response; it has an internal condensing system for the safety of families and small children; it comes with a solid warranty that will cover you for years to come.

Heat Output and Flow

Would I surprise you if I said the NPE-210A Premium Condensing comes with a temperature range of 98°F - 140°F? You can laugh, but this is a sign that Navien doesn't compromise when it comes to customization. It's a brand that wants its customers to have options, so between 98°F - 140°F and 10.1 GPM, this is a nice unit. 


While I always recommend letting a trained technician handle the installation of tankless water heaters, the NPE-210A Premium Condensing is one that a determined DIYer could handle. This is because of both its compatibility with existing systems and its detailed instruction manual that anyone can understand.


-Low-NOx emissions (≤ 20ppm)
-Strong GPM works even in large homes
-No flow delays when firing up product in the mornings


-Display is rather small and hard to read
-Installation of gas-powered unit requires venting
-Can get expensive, especially with add-ons

*The Winner*

The Best Navien Tankless Water Heater

NPE-240A Premium Condensing

The NPE-240A Premium Condensing is simply the best value for the money. Not only will you enjoy one of the highest flow rates on the market (11.2 GPM), but you'll also reap the cost- and energy-saving benefits of 97 percent thermal efficiency.

It's a low-NOx system, so you won't harm your indoor air quality with its installation, and you can customise its temperature from 98°F - 140°F.

Speaking of customization, the NPE-240A Premium Condensing also comes with a myriad of special features and controls, including cascade functions and Celsius-to-Fahrenheit conversion options.

All in all, the NPE-240A Premium Condensing is what you're looking for when only the best will do.

  1. Thanks for this nice summary. I notice when you give cons for the NPE 180 condensing you mention that “Energy efficiency is lacking when compared to other Navien products”. When I checked out the certification summary on Navien’s website for both the NPE240A condensing and the NPE180 condensing both are rated the same with regard to energy factor, uniform energy factor, natural gas consumption, and annual cost to operate. What measure of energy efficiency were you referring to in your statement that I quoted above?

  2. I have not had hot water For 3 weeks thay come and repair ever day or so and do not know what is worng can you call my pluner onze 203876 7875

    • Hello Edward.

      I’m sorry to hear that your system is not working properly. We are a review/blogging site for various brands and systems, but are not a service or warranty center for any of these brands or systems. Please see our disclaimer page if you’d like to know more ( That said, we’d be glad to help you think through how to find a solution to your issue. Did you purchase a Navien tankless unit? Did a licensed plumber install it? Have you reached out to the manufacturer to help you troubleshoot your issue? Is it still under warranty? If so, you should contact the manufacturer immediately. I’m sure Navien would want you to be a satisfied customer. Three weeks is indeed a long time. Please keep us posted right here as to how you problem is resolved. Thank you for reaching out. Your story is important for our readers to hear.

  3. What is the NPE-240A Premium Condensing? I contacted Navien and that item does not exist. They only have the NPE-240A NG. I searched all over the Internet and on Navien’s site – no mention of NPE-240A Premium Condensing.

  4. Moved into a house in June 2017 with a Navien CH-240 unit. Below is the repair history on it up until yesterday. I’m $2200 in on repairs in less than four years. Keep that in mind as you decide on what tankless unit to use.

    November 24, 2017:
    Problem: no hot water, flow sensor stuck
    Solution: freed flow sensor & restored hot water. ordered new flow sensor, returned to site and replaced flow sensor.Flow sensor: $73.32
    Total cost for job: 288.22

    December 26, 2017:
    Problem: limited heat
    Solution: found air in system, bled air. also found recirc timer causing unit to neglect heat for long periods of time. No parts needed.
    Total cost: $139.50

    May 6, 2019:
    Problem: leak
    Solution: Found condensate clean-out O-ring leaking, replaced O-ring. O-ring:$2.00
    Total for job: $151.50

    January 18, 2020:
    Problem: no hot water or heat
    Solution: found leak in heat exchanger, 3 way valve stuck, got that to open, sent photos to navien for warranty consideration, Navien sent new heat exchanger & 3 way valve. returned to site, replaced heat exchanger assembly and 3 way valve. Parts- cost covered by Navien,
    Total for job: labor x3 trips = $448.50

    June 8, 2021:
    Problem: E03 error/limited hot water
    Solution: found pressure sensor and 3 way valve bad, ordered parts, returned to site and replaced pressure sensor, 3 way valve, and 30 psi T&P valve. 3 way valve- $110, pressure sensor- $34.50, T&P Valve-$29.00
    Total for job: $397.75

    September 4, 2021:
    Problem: E03 error/E011 error, no hot water
    Solution: replaced control board and pressure sensor. Control Board $380.16, Freight for Control Board: 139.24, Pressure Sensor: 34.11, Labor: 2x trips, $224.25
    Total for Job: $777.76

    • We are sorry to hear of the troubles you have had with the Navien unit. That’s a lot of cash. I hope that you have contacted Navien about your troubles. Generally, we have not heard many complaints about Navien units, but it could be related to how well the unit had been serviced prior to you owning it. For instance, if the previous owners were not flushing in annually or bi-annually, that could have caused problems. Also, it may not have been initially installed correctly, or perhaps the unit was too small a GPM for the use that it did receive and maybe was overworked. Anyway, we’d be interested in hearing what Navien told you regarding your troubles and costs. Thanks for telling your story here.

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