Navien Water Heater Reviews 2024

Updated on:
January 6, 2024

In today’s world, water heaters are no longer a luxury but a necessity. Hot water is necessary for cleaning dishes and certain fabrics. Not only that, we’ve all had the dreadful experience of running out of hot water in the middle of a shower. 

To ensure that you always have hot water whenever you need it, you should get a tankless water heater of superior quality.

Navien tankless water heaters are well known in the water heater market. The company has built a solid reputation for itself to become one of the most prominent brands in the industry. But do they have the right model for you? Let’s find out.

Who Is Navien?

Since its establishment in the late 1980s, Kyungdong Navien has been making boilers and water heaters for its South Korean and Asian customers. However, in 2006, Navien Inc. entered the US market and has grown to become one of the most successful manufacturers in the North American home-comfort industry. 

It has some of the most popular condensing and non-condensing tankless water heaters, combi-boilers, and boilers on the market. Cutting-edge technology, exceptional efficiency, and unparalleled reliability make Navien tankless water heaters a top choice among contractors and homeowners alike.

Navien has established a remarkable reputation, driven by a commitment to trust and customer satisfaction. As one of the go-to choices for tankless water heaters, Navien has garnered widespread acclaim for its superior performance and cutting-edge features. The company’s solid reputation extends to its excellent customer service, ensuring homeowners receive exceptional support throughout their water heating journey

What Is the Difference Between Condensing and Non-Condensing Water Heaters?

A condensing tankless water heater saves space and provides continuous hot water for your house, but what distinguishes it from a non-condensing unit is its capacity to effectively utilize extra heat by using a second heat exchanger, which boosts efficiency and delivers more hot water.

Because tankless water heaters do not store their water supply in a tank, water is heated (by a natural gas burner) quickly as it passes through the tankless unit’s heat exchanger. Condensation occurs when a second heat exchanger is used to catch and cool heat that would otherwise be lost. This method of using extra heat rather than venting it out of the heater enables your condensing tankless unit to save more energy, resulting in a Uniform Energy Factor (UEF) of more than 0.90 and more hot water delivery than non-condensing tankless heaters.

The Best Navien Water Heaters for Your Home

Let’s take a look at some of Navien’s condensing tankless water heaters now that we’ve established that it’s a serious player in the tankless water heater industry with years of expertise and competence.

I used professional advice and reliable customer feedback to recommend the best Navien tankless water heaters to my readers. One week of study and comprehensive testing by certified specialists has resulted in one of the best Navien tankless water heater reviews available online.

This review highlights various models that showcase the best industry standards for high efficiency, low emissions, and multipurpose use. Two tankless model lines are available, the NPE-A and NPE-S.

Let’s have a look at the best that each model line has to offer.

1. Navien NPE-180A2 Condensing Tankless Water Heater

The Navien NPE-180A2 is a tankless water heater with a high level of efficiency. In this model number, the A2 indicates that it is an (A) advanced version, and the (2) indicates that it is the second generation, which is the most recent.

The ComfortFlow technology from Navien is the first and only system that includes an insulated buffer tank and a recirculation pump as integral components. The buffer tank reduces the cold water sandwich effect (in which warm or hot water is interrupted by a burst of cold water) and minimum flow rate problems that are typical with tankless water heaters. The recirculation pump reduces the amount of time that hot water is available, hence lowering your water bill. The ComfortFlow system recirculates hot water through the supply pipes, reducing the wait time for hot water.

This 150,000 BTU per hour natural gas water heater has the following features:

  • It has an optional NaviLink Wi-Fi remote control system, NaviLink, that turns the NPE-180A2 into a smart condensing tankless water heater. Customers with smartphones and tablets will be able to remotely regulate temperatures, examine usage statistics, and get diagnostic alerts.
  • You can use either natural gas or propane as a fuel source for this tankless water heater.
  • The optional Navien HotButton hot water activation system controls the internal recirculation pump and gas-fueled burner to heat water in the supply lines and deliver hot water whenever it is required.
  • The Ready-Link manifold system enables simple wall or rack installation.
  • This Navien tankless water heater has two stainless steel heat exchangers for increased efficiency.
  • The low NOx gas burner has a heat capacity of 15,000–150,000 BTU per hour.
  • This Energy Star-qualified Navien tankless water heater has a Uniform Energy Factor of 0.96.
  • This unit has a maximum flow rate of 8.4 GPM (gallons per minute) at 35°F and 1.7 GPM at a 140°F temperature rise. Ideal for a household of five people.
  • An H2Air Kit circulates hot water for the hydronic air handler using the NPE-A pump. This eliminates the need to acquire an extra heating system circulator. The H2Air Kit from Navien comprises an add-on controller that enables space heating and DHW system integration between NPE-A series tankless water heater models and a hydronic air handler. It is designed for both retrofit and new construction residential applications.
  • This unit can be installed both indoors and outdoors.
  • This water heater is available with a residential 15-year heat exchanger warranty and a 5-year warranty on parts. There’s also a separate commercial 8-year warranty on the heat exchanger.

The Navien NPE-180A2 is available in select stores for around $2,650 plus installation costs. It may seem a bit much, but you are truly getting your money’s worth in terms of performance and efficiency.

2. Navien NPE-240A2 Condensing Tankless Water Heater

The Navien NPE-240A2 hails from the same class as the NPE-180A2. This means that it shares the same features, including dual stainless steel heat exchangers and Navien’s patented ComfortFlow technology, which uses a buffer tank, a recirculation pump, and fine-tuned controls to eradicate the cold water sandwich effect and minimum flow issues.

Other similar features include a built-in HotButton control panel, energy star qualification, ultra-high efficiency condensing technology, low NOx emissions, remote control, a dual venturi system for field gas conversions, which creates a better combustion control and turn down ratio, and your choice of propane or natural gas as a fuel source. 

However, unlike the previous model, the 240A2 has the following extra features:

  • A maximum flow rate of 11.2 GPM at 35°F and 2.8 GPM at 140°F temperature rise. 
  • The low NOx gas burner has a heat capacity of 19,900–199,900 BTU/Hour. 
  • The in-built Cascading technology allows you to retrofit up to 32 NPE-240A2 models. 

All this means that you can access hot water faster and more efficiently than the NPE-180A2. 

This model is also more expensive, with most retailers letting it go for around $3,500 (plus installation costs). This may seem out of reach to some, but you’ll be investing in a highly efficient tankless water heater that guarantees $195 in annual operating costs compared to $249 for other tankless water heaters and $319 for tank-style water heaters.

Additionally, this Navien NPE-240A2 tankless heater is available with a residential 15-year warranty on the heat exchanger and 5 years on parts. There’s also a commercial 8-year warranty on the heat exchanger and 5 years on parts.

3. Navien NPE-180S2 Condensing Tankless Water Heater

The (S) in the NPE-S model line stands for standard efficiency, and the (2) denotes the current generation of this Navien tankless heater. The difference between this and the NPE-A models is the inclusion of a buffer tank and recirculation pump on the advanced model. However, this does not mean that the S line isn’t any good. It’s a formidable alternative to non-condensing residential water heaters and other tank-style water heaters.

The NPE-180S2 is an innovative condensing combination boiler. It has a UEF of 0.97 and an energy factor of 0.99, making it more energy efficient than other tankless water heaters in its price range. Other interesting features include the following:

  • This wall-hung water heater is small, stylish, and allows you to save up to 80% more space than traditional tank water heaters.
  • Dual stainless steel heat exchangers provide greater resistance to corrosive wastewater, resulting in a more robust construction.
  • Field conversion to propane or natural gas. A free replacement conversion kit is usually available during purchase.
  • Optional recirculation pumps can be fitted to multiple cascading units where a dedicated return line is not available. This external tank system is known as NaviCirc. It is a basic plumbing device that reduces the wait time for hot water at the faucet without the need for a special recirculation return line by using the existing hot and cold water pipes in your house.
  • An optional Navilink Wi-Fi control module can be installed.
  • This model includes an LCD backlit control panel that displays the temperature and flow rate and allows for self diagnosis.
  • This unit is Energy Star qualified with a maximum burner output of 150,000 BTU/hour and a flow rate of 8.4 GPM at 35°F and 4.2 GPM at 67°F.
  • The NPE-180S2 has a 5-year parts warranty and a 15-year warranty on the heat exchanger.

This NPE-180S2 water heater is available in stores at a cost of $2,300, plus installation costs. 

4. Navien NPE-240S2 Condensing Tankless Water Heater

This Navien tankless water heater has the exact same features as the previously mentioned unit. However, the NPE-240S2 is the top of the line model. It is built for more efficiency and a higher flow rate. These extra features include the following upgrades:

  • A low NOx emission burner with a maximum output of 199,000 BTU/hour
  • A maximum flow rate of 11.2 GPM at 35°F and 5.7 GPM at 67°F
  • A net weight of 75lbs, 8lbs more than the NPE-180S2

This Navien condensing combination boiler retails at $3,050 at select stores.

The Bottom Line

These tankless water heaters are very good at reducing heat loss. They have a lot of great features, like being able to support homes with fixtures on more than one floor, saving energy, and delivering hot water on demand.

So, if you want to choose the best water heater for your regular needs, any of these four Navien models is a great choice. They have a high flow rate and good energy efficiency, so you can expect positive returns.

If you are worried about the longevity of your new water heater. Check out my article “How Long Do Water Heaters Last” to learn about the signs to look out for before you replace your unit.

Navien Water Heaters Review Methodology

This section outlines the process I went through when reviewing the best Navien tankless water heater.

Step 1: A list of all Navien water heaters

I started work on my analysis by creating a list of the most popular Navien tankless water heaters on the North American market. This involved hours of going through websites such as Amazon, Home Depot, Wal-Mart, Target, and Costco, trying to find out which Navien tankless water heater is the bestseller. In the end, I had managed to single out four models that seemed to be customer favorites. 

Step 2: Online reviews

This next step involved checking out customer reviews on major review sites like Better Business Bureau, TrustPilot, Google Business, and Amazon Reviews. It was important to find out the user sentiment so that I could determine whether the benefits that the manufacturer promised were actually being enjoyed by the customer. 

Step 3: Interviews with real customers

Next, I needed to figure out a way to talk to real customers who had first-hand experience of using a Navien water heater. The only surefire way was to do a questionnaire survey. So I called up a couple of friends and organized a door-to-door survey within a 30 mile radius of our locality. I also got in touch with a couple of licensed plumbing contractors to find out about their experiences with Navien’s tankless models.

I also held an online survey on Facebook and Twitter just to broaden the scope of my reach. After three arduous days of legwork, I had all the information I needed .

Step 4: Getting in touch with Navien

I had to get in touch with the manufacturer to push them for answers to some of the few critical reviews they received from customers. This enabled me to find out how they interacted with customers and how their customer support representatives behaved under pressure.

Step 5: Test drives

I figured that if I was going to be objective in my review, I needed to speak as an authority on this subject. This meant that I had to purchase the four most popular units and run a controlled test drive. After half-way convincing my spouse, hiring a water bowser, and “borrowing” some warehouse space from a close friend, I ran a test drive of all four Navien models. Ultimately, I had everything I needed to sit down and write this review.


When it comes down to it, every home needs a water heater of some kind or other. If you’re in the market for a new water heater, Navien is a reliable, well-made brand with several quality heaters to choose from.

These four are the best Navien tankless water heaters currently available on the market. Regardless of which Navien model you decide to purchase, these water heaters are assured to provide superior performance and durability. 

Curious about what other brands have to offer? Read my review of the 7 best tankless water heaters for your home to find out more.

And if you’re looking for reviews on water heaters other than Navien, our comprehensive collection of water heater reviews covers a wide range of brands and models available on the market. Find out more here.

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Terry Schmunk

I had the Navien 240A condensing water heater installed in my home June 2015. I have had the heat exchange unit flushed this year. I cleaned the condensate water cleanout and inlet water filter myself today. The o-ring on the condensate water clean out is currently leaking and is possibly because of grit on the o-ring…tbc. My biggest worry is, I found a brown oily residue under the heat exchanger on the black plastic belly and at the top of the exchanger next to the vent outlet. Also the vent on top of the unit is corroded around the pipe clamp. What is the oily residue and what about the corrosion at the vent on top of the unit?

James Layton

What you describe has been a years-long issue for many Navien customers. I have seen photos of the oily substance. I have also been shown photos of the corrosion at the vent area. While there are a few theories, it appears that the exhaust gasses vent just enough to cause the corrosion at the vent area. Some people believe the gasses are corrosive and cause some type of reaction with the plastics, creating a brown oily residue. There have been recalls on Navien units. Here is one link from the Consumer Product Safety Commission recall. I would investigate to see if your model has been recalled.

J Michael

After reading this glowing article on Navien tankless heaters, it was a complete shock to see that not one Navien model made your list of 7 “best” tankless heaters. Can you explain why that it so? What is it lacking or what is its major problem such that you don’t see it in the top 7. How far behind the other top 7 brands is the Navien and what is putting it there?

James Layton

J. I am new to the organization and have not dug into this review yet. Reviews are periodically updated, so there is a chance this one will be updated with new info at some point.