Here’s The Best Tankless Water Heater In 2018

Finding the best tankless water heater can be a little bit of a challenge. There’s a lot and I mean A LOT of overwhelming information online.

If you’re looking for a good place to start you’ve come to the right review guide!

Water heaters are a must have, but big water bills are not. There is a growing trend of people who are opting to go with tankless water heaters instead of the traditional tank water heater.

Tankless water heaters are powered by natural gas, propane, or an electric unit. Below, I will discuss the numerous benefits of owning a water heater, some of the drawbacks, and how they measure up against tank water heaters.

Benefits of Owning a Tankless Water Heater

Saves energy

Since there is no tank storing and heating 50 gallons of water at any given moment, tankless water heaters use up to 50% less energy. The heater is only used when you use hot water, minimizing the amount of energy the heater uses. Not only can this be good for the environment, this can also save you money.

Saves space

Again, since there is no big tank, tankless water heaters take up much less space and can usually just be mounted right on the wall. This gives you extra storage space for whatever you want. When I switched to a tankless heater, I was able to reclaim my old shed that used to only hold my water heater.

Lasts longer than tank heaters

Tankless water heaters have been known to last up to ten years longer than tank water heaters. This means you replace it less often and save even more money over time.

No flood risk

Since there is no tank, there is also no chance of a ruptured tank flooding your house. A burst water heater can be a nightmare. It is expensive to fix and can cause property damage to your house. By using a tankless heater, you completely eliminate this as s possibility.


Tankless v. Tank Water Heaters

Tankless water heaters, although they may significantly cut your bill, also have a much higher initial cost than tank water heaters. Tankless heaters can cost up to 3 times as much as tank heaters, but they are a good investment.

The maintenance of tankless heaters over their entire lifetime, is much cheaper than the maintenance of tank water heaters. Tank heaters are also much harder to control than tankless heaters. Tankless heaters are controlled electronically, usually with a remote control, and can be programmed to heat the water to a precise temperature.

Tankless water heaters also have an unlimited supply of hot water. Tank heaters are limited to the capacity of their tank, but tankless heaters heat up the water as it is needed and continues to do so until it is no longer needed.

Lastly, tankless water heaters are much more energy efficient and most of them are even Energy Star certified. The electric tankless heaters emit no greenhouse gases and have a very small environmental footprint.


EcoSmart ECO 27

The EcoSmart Features:EcoSmart ECO 27

Precise temperature control in one degree increments:

The electric control of this heater makes it easy to get the exact temperature that you want.

Compact and sleek design:

The sleek design on this heater is unlike what you would typically expect from a water heater. Because there is no tank, it is not large and bulky; instead, it is sleek and compact.

Copper components increase durability and make repairs easy:

The copper parts of this heater make it easy to interchange parts and make minor repairs inexpensively.

Self-modulating flow sensor:

The self-modulating flow sensor of this heater regulates how much energy is used heating water.


  • Electric
  • Wattage: 27 KW
  • Flow rate: 3 gallons/min @ 37°F
    6 gallons/min @ 67°F
  • Temperature range: 80°F to 140°F
  • Dimensions: 17H x 17W x 3.625D inches
  • 240 V required


This heater can keep up with high water demands and in the right climate, can easily be used to heat an entire house’s water supply.

It is known for being durable and standing the test of time. This heater is also one of the most affordable ones I found.



The only downside of this tank is that it will not perform correctly in all climates. Only people in certain areas can use this heater.

However, the same company makes several other models aimed at different climates, so if this heater is not viable in your area, you can always try a different model.


SioGreen IR6000 Infrared

The SioGreen Features:SioGreen IR6000

Anti-scald protection:
The anti-scald protection in this heater only allows the water to be heated to a certain degree. Once the water reaches 131°F, it automatically shuts off.

This prevents accidental burning, which is especially useful if you have kids who don’t realize how hat the water can get.

Zero maintenance:
This tank requires no routine maintenance like typical water heaters.

You don’t have to flush it out annually or replace any of the parts; it is built to last. This is also useful because it saves you lots of time and money over the years.

Infrared energy:
This heater uses unique infrared technology to heat up quartz bars, whereas other heaters use metal heating tubes. The quartz heating tube and infrared energy are used to heat the water without ever touching metal.

Leakage current protection:
This heater comes with a built-in CFGI, which protects against power outages and other potential problems.


  • Infrared Electric
  • Wattage: 14 KW
  • Flow rate: 3.6 gallons/ min at 30°F rise
    2.0 gallons/ min at 60°F rise
  • Temperature: 130°F
  • Dimensions: 20 x 14 x 6 inches
  • 240 V required


Since the water never touches metal to heat up, this also eliminates the problem of corrosion.

In other water heaters, the metal heating tubes would have to touch the water, which over time would lead to corrosion and would have to be regularly replaced.



Unfortunately, this is another model that works best in certain areas.

If this water heater will not perform well in your climate, there is no point in wasting your money on it, instead look for a water heater built to withstand whatever climate you live in.


Bosch Tankless Water Heater

The Bosch Features:best electric water heater

External temperature control knob:
The knob on the outside of the heater is how the temperature is controlled. It is super easy to use and there’s no chance of you losing it, like a remote.

Flow sensor:
Some people are skeptical of tankless water heaters’ ability to keep the water hot, even if it’s running for a while.

The built-in flow sensor prevents this from happening by ensuring that all the water coming out is the same temperature.

Its compact design makes it easy to install anywhere. Even if you have absolutely nowhere in your house to put it, don’t worry, it can easily be installed on an exterior wall as well.

Different sizes available:
The Bosch Electric Tankless Water Heater comes in a few different sizes, which means it works on different sized houses.

A water heater that is too big or too small for your house will either cost you way more than you have to spend, or cost you less but not be able to service your whole house.


  • Electric
  • Wattage: 17.3 KW
  • Flow rate: 2.3 gallons/ min at 45°F rise
    1.6 gallons/ min at 75°F rise
  • Dimensions: 15.5 x 4.5 x 12.5 inches
  • 240 V required


The nice part about this heater is that it can last twice as long as your average tank water heater.

You can expect this heater from Bosch to last over 20 years, and if it doesn’t, there is a 5 year limited warranty on its heater exchanger, and a 2 year limited warranty on other parts.



Unfortunately, I have not been able to get a solid answer as to what the exact temperature range of this heater is.

However, when I tested it, the water came out just as hot as it did with any other heater. So although I don’t know just how hot it can get, I know it gets hot enough.


Rheem RTEX-13

The Rheem Features:best water heater

Temperature control:
With this incremental temperature control, it is easy to set the temperature to whatever you want between 80°F and 140°F, it is much more precise than tank water heaters and is accurate within one degree.

Copper heating elements:
The copper heating elements in this heater make it very durable, and very effective because it is a really good conductor of heat.

Easy to use:
This heater can practically be installed and never thought about. Once you set the temperature, you probably won’t have to change it very much.

Plus, setting the temperature is easy to do with the large, easy to read LED temperature display.

As far as tankless water heaters go, this is one of the most affordable one. It only puts you back a couple hundred backs, instead of possibly thousands of dollars, like others.


  • Electric
  • Wattage: 13 KW
  • Flow rate: 1.5 gallons/min @ 60°F rise
    4 gallons/min @ 20°F rise
  • Temperature range: 80°F to 140°F
  • Dimensions: 9 x 4 x 13 in
  • 240 V required


The Rheem RTEX comes with a 5 year no leak warranty, and a one year parts warranty.

I always love warranties because it reduces any of the risk associated with purchasing.



The only downside to this is that the copper heating element will more than likely need to be replaced.

However, thanks to the warranty and the easily replaceable nature of the parts, this should no hassle for a professional, and shouldn’t cost too much either.


Rinnai RUC98iN Ultra Series

The Rinnai Features:Rinnai RUC98iN Ultra Series

Venting options:
Since this is a gas powered heater, you will have to have some form of ventilation. However, you are not locked into one specific method; this Rinnai heater can either be used to concentric, or PVC venting.

The warranty:

Differs depending on if it is for commercial or residential use. For residential use, you will receive a 12 year limited warranty on the heat exchanger, 5 year warranty on parts, and a one year warranty labor, which you can choose to extend to 5 years.

Although it might be heavy, it can be installed pretty much anywhere, thanks to its compact design and simple shape.


  • Natural Gas
  • Flow rate: 9.8 gallons/min
  • Temperature range: 98°F to 140°F
  • Dimensions: 10 x 18.5 x 26 inches
  • 120 V required
  • Low emissions
  • Warranty


Not only does this heater have an easy to use temperature control on the exterior, it is also compatible with the full line of Rinnai digital controllers.

This means you get to choose how you want to control the heater.



This heater has some great features. Unfortunately, that also means it is one of the more expensive ones on this list, however, it is worth the money.

Ultimately it is up to you to weigh the costs and benefits and make the final decision.


Atmor AT-910-24TP ThermoPro

The Atmor Features:Atmor AT-910-24TP ThermoPro

Precise temperature control:
Like some of the others, this heater has a digital display temperature control on the outside of the unit.

You can set the temperature at any degree between 90°F and 135°F; the control goes up incrementally by one.

Temperature stability:
This heater amazingly maintains the temperature you set it at. Instead of wavering, or being several degrees off, this heater maintains water temperature within 0.5 degrees.

This heater comes with 2 year warranty, and although it is limited, it is still a great warranty plan, which is always nice to have in place.


  • Electric
  • Wattage: 24 KW
  • Flow rate: 4.6 gallons/min capacity
  • Temperature range: 90°F to 135°F
  • Dimensions: 5.25 x 17.38 x 13.38 in
  • 240 V required
  • Splash proof


This heater is the least expensive one on the list, making it a really great option for anyone on a budget.

There is no need to spend thousands of dollars if this one suits your needs.



As with most other water heaters, you may encounter a few problems when it is first installed.

Some of these problems include the water not being hot enough or the water being too hot.

However, there is a very useful user manual included with an entire troubleshooting chart for any problems you may encounter.


Stiebel Eltron Tempra Plus

The Stiebel Eltron Features:best tankless water heater

Digital temperature control:
The external digital control is easy to manipulate and can be used to set the temperature anywhere from 86 degrees to 140 degrees. However, it is not recommded to every set it above 122°F for safety purposes.

Frustration free:
This heater is certified to be frustration free. That means you can be assured that this is easy to use and reliable.

The Tempra Plus comes with a seven year no leak warranty and a three year parts warranty. This is really nice because most other warranties are only for one or two years.

Silent operation:
Another great thing about this heater is that it is totally quiet while it is in use. This means it is not a distraction for other people in the house and can basically be forgotten about once it is installed.


  • Electric
  • Wattage: 24 KW
  • Flow rate: 8 gallons/ min capacity
  • Temperature range: 86°F to 140°F
  • Dimensions: 21.5 x 19.5 x 8.8 inches
  • 240 v required


Unlike gas powered heaters, this heater requires no venting, making it easier and less costly to have installed.

It also makes it easy to put pretty much anywhere in your house.



Like the other electric heaters, this one has specific models that work in specific climates.

It is easy to find which model is best for you though. The manufacturer has a map available that tells you what model is best based on where you live.


Takagi T-KJr2-IN-LP

The Takagi Features:Takagi tankless water heater

Direct vent:
This propane heater has a direct vent, like most gas fireplaces. The good news about this is that direct vents aren’t too hard for professionals, so hopefully that will keep the installation price lower.

Energy star certified:
One argument people use against gas powered heaters is that the emissions can be bad for the environment.

However, this heater has very low emissions, is very energy efficient, and is even Energy Star certified.

This heater comes with a 10 year heat exchanger warranty and five year warranty on the other parts of the heater.njm

Freeze protection:
With tank water heaters, in cold winter months, you have to leave a faucet on in your house so that the water and pipes would not freeze.

However, this tank comes with freeze protection, meaning you can have hot water whenever you want, despite what the weather may be.


  • Propane
  • Maximum BTUs: 140,000 / Minimum BTUs: 19,500
  • Flow rate: 6.6 gallons/min capacity
  • Temperature max: 167°F
  • Dimensions: 6.7 x 13.8 x 20.3 inches
  • 120 v required


This heater isn’t a big fancy heater for large homes, because that would be really expensive.

But, it is perfect for apartments or small homes, making it great for people who live alone or have small families.



Since this is a propane powered water heater, the installation may cost a little more.

Usually, when you buy it you can buy the installation too though, that is probably the best option.


Things To Consider Before Buying

What type of tankless heater is right for you?

The two main types of tankless heaters are electric and gas powered. There are also different gas powered heaters, like natural gas and propane powered heaters.

It is always a good idea to do additional research after finishing reading this, but I would recommend you choose an electric tankless water heater.

Electric models are just less of a hassle all the way through. They cost less to install, they do not require venting, they require no maintenance, they cost less to operate, and they have a smaller environmental impact.


What size heater do you need?

There is no need to buy a bigger heater than you need, especially because it will cost you more money. One way to determine what size heater you will need is to add up the flow rates of all the faucets in your house.

This is the flow rate that you want your heater to have, that way it could supply water to your whole house at once if necessary.

If you choose a heater that is too small, you will only be able to use one or two appliances at a time, which will just become a pain in the neck.


What are the initial startup costs?

As I mentioned earlier, the initial startup cost is the most expensive part of tankless water heaters.

It can cost you up to a couple thousand to install one, depending on what kind you get and what size it is.



Electric vs. Propane vs. Natural Gas

I am a big proponent of the electric tankless water heaters, for the reasons I’ve already mentioned, such as the lower installation and maintenance costs.

However, gas powered heaters have their own strengths, and ultimately many things will factor into your choice of an electric, propane, or natural gas powered tankless heater.

No matter what fuel source you choose to use, you will receive the benefits of owning a tankless water heater. In some areas, electric models are not offered, in which case natural gas or propane fueled heaters are just as good.


Installation: DIY or Professional

Never try to install a tankless water heater yourself. It is a very complicated, and potentially dangerous, process if you do not know what you are doing.

Even if you’re the handy man who does all the home improvements, it’s really best to leave this one to the pros. Having professionals install your heater ensures that it is installed correctly and decreases the risk of something going wrong.

We hope you’ve enjoyed our review of the 8 best tankless water heaters. Have questions? Drop us a comment below!