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Navien Gas Tankless Water Heater Reviews [Model: NPE240S-NG]

***This water heater is no longer available. However, you can check out this article if you want to see better choices of tankless gas water heater in the market today.

Our Rating
Navien gas tankless water heater reviews
  • Warranty of 15 years.
  • High Tech Controls.
  • Powerful and Energy Efficient
  • Not much maintenance needed

Why Go Tankless?

Tankless water heaters are becoming more and more popular as time goes by.

People already know about the classic water heaters, and all the issues those bring, but, tankless models have a lot more to offer. 

They only use energy when you use water, so you’ll definitely save up on the energy bills.

What’s even better, you can never run out of hot water with a tankless water heater like this one.

And, if you are already browsing the internet to find yourself the best gas tankless water heater, you probably already know that it does offer certain benefits.

What To Take Into Consideration?

Of course, there are a lot of things you would have to consider when purchasing a tankless water heater.

You will, of course, have to focus on energy efficiency. However, that is far from the only thing to think about. Other factors to consider are the water flow and safety.

So, let’s get into it and see if this Navien model is the perfect heater for you.

If you want to save money and buy an affordable tankless heater, the NPE-240s is probably a good choice. Navien is one of the factories that have the best reputation out there.

In fact, it has been one of the best companies when It comes to water heating technology. And they have been around for a while, perfecting their designs.

Their Navien NPE240s model is a top-notch heater which has been collecting almost perfect reviews ever since it came out.

We should also mention that this heater boasts an incredible 15-year warranty. So, as long as you hire a certified professional you are good to go.

Of course, we couldn’t just believe the reviews of others so we decided to take a look ourselves and make our own.

Navien Gas Tankless Water Heater Reviews - 7 Key Features

1. The Basics

This premium water heaters weighs 75 pounds, its dimensions are 17.3 x 13.2 x 27.4 inches.

You can hang it on just about any wall, it is really easy on the eyes, so you won’t have to worry about an eyesore in a room.

Another great thing about this Navien model is the fact that it is made of stainless steel - instant guarantee of durability.

You can set water heating to temperatures between 98 and 140 degrees Fahrenheit.

2. Energy Efficiency and Power

This is a very powerful unit. It can provide you with 199,990 BTU each hour and it can do so efficiently.

Namely, the energy efficiency of this model is even better than the efficiency of their previous model. Navien boasts an almost insurmountable score of 0.98ef.

This score is a definite proof that an industry-leading company is in question. Not to mention that Navien boasts that their heaters can go up to 0.99ef.

However, since it is gas operated, you might be worried about the price movements of natural gas.

Well, this model allows you to easily convert the unit to work with field gas instead. Other than that, it will use up to 200 watts of power for other operations.

Installing this unit will definitely improve your Home Energy Rating Score.

Also, if you intend to use it in a huge building, you can easily cascade up to 16 heaters. And they have also done wonders with the load-sharing technology.

As soon as one heater reaches 4/5 of its capacity, the next one will turn on to share the load. This ensures that your costs stay down.

3. Water Flow

This wall-hanging unit can provide over 11 gallons per minute of water flow. This ensures that there is enough hot water for any a home.

In fact, we have been unable to strain the flow of this machine with 3 showers running at the same time.

Next to that, we turned two taps on. And, even in spite of all of that, we still had enough hot water to wash the dishes by hand.

This is in part thanks to the amount of BTUs this unit can put out. So, this water heater can easily satisfy hot water needs of an average household with 3 bathrooms.

What we loved about it next to the incredible amount of hot water? Well, it functions wonderfully silently, unlike some other models we tested.

4. Safety

We were very happy to notice all of the safety features we could want a heater unit to have. The flame sensor is there to make sure that there is no gas going if there is no fire.

It also has an operation detector for the ignition, the high limit switch for water temperature, the high limit sensor for exhaust heat,  APS, and the power surge fuse.

So, you are pretty much covered when it comes to the safety of this product. Just make sure to have a professional install it. It is not something you should consider a DIY project.

5. Controls

If you want a heater that is easy to use, you are looking at the right one with Navien N240S NG.  

The touchscreen control center on the front panel makes it appear high-tech but remains user-friendly.

Everything is pretty clear, and if something seems confusing, their user manual will clear it up.

However, we have to praise Navien for their mobile app. Yes, you can actually download an app that will let you use your Wi-Fi connection to control the temperature remotely.

 And not only that, but you will be able to check the usage data and receive various diagnostic information whether you’re at work, or on the couch.

You’ll know if something’s wrong in a second. To us, this is a huge advantage over similar models.

6. Venting

The system in charge of venting is a forced draft direct vent with 2-inch  PVC pipes. Navien is all about performance. And, that is why they are using PVC vent pipes.

PVC allows for better condensing and will thus further reduce the energy expenditure. And you can use common venting for up to 8 units.

This makes this residential unit ideal for large companies as well. However, if you do not like all these pipes and vents, check out our reviews on the electric tankless water heater.

7. Maintenance

When it comes to maintenance, this Navien model isn’t a demanding device, even though it is high-tech. NPE240S-NG requires yearly descaling and filter cleaning.

If your water supply is problematic, you might need to flush the system with vinegar more than once per year, but it’s a fast and simple process, so it won’t be much of a bother.

The Pros and Cons


  • Incredibly energy efficient unit that will save you money in the long run.
  • A warranty that lasts for 15 years.
  • Wi-Fi controls via their mobile phone app.


  • It takes a minute for the hot water to start flowing.
  • Doesn’t come with the venting kit.

Final Verdict

Navien NPE240S-NG Review

Our Rating

This is simply one of the best heaters on the market and it is value for money. It doesn’t take up a lot of space, saves energy and can provide enough water for a huge home.

And we simply love the remote control app they have. Having the ability to adjust the temperature or run diagnostics from your couch is really a great feature.

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    Verner Ellen

    Hi, my name is Verner Ellen. I am a homebody whose interest is in getting the best home tools and equipments to help with the the everyday house chores. I also love fitness, cooking and grilling. Maintaining a clean and comfortable home is my lifelong passion.