Best Electric Tankless Water Heater | Reviews & Ratings (2021)

Picture this – you have a water heater that can be placed anywhere in your home. Anywhere. Anywhere at all.

You don’t have to worry about space, about the dangers of gas leaks, or even about ventilation. You don’t have to worry about anything at all!

That sounds like a dream, right? Well, it’s not – at least not when you purchase the best electric tankless water heater for your home.

A good electric tankless water heater will not only save space, but will operate quietly and offer superior energy efficiency. You can put one of these units just about anywhere, making it the ideal choice for residential homeowners and commercial property owners alike.

Not sure what to look for? Here are some tips on how to find the best electric tankless water heater – and our picks for the best products around.

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Best Electric Tankless Water Heater – Comparison

PictureProduct NameVoltageWeightPrice
Rheem Residential TanklessRheem Residential Tankless240 volts17.8 pounds
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Stiebel Eltron TanklessStiebel Eltron Tankless240 volts1 pounds
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Bosch Electric TanklessBosch Electric Tankless240 volts4.9 pounds
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EcoSmart Eco 27 ElectricEcoSmart Eco 27 Electric240 volts11 pounds
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AB WiseWater TanklessAB WiseWater Tankless240 volts14.6 pounds
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iHeat Tankless S-14 iHeat Tankless S-14 240 volts8 pounds
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Marey ECO150 14.6kWMarey ECO150 14.6kW220 volts10.1 pounds
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ECOTOUCH Electric TanklessECOTOUCH Electric Tankless240 volts7 pounds
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Atmor AT-D18TP-AZ ThermoproAtmor AT-D18TP-AZ Thermopro240 volts17 pounds
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Ariston GL4S Electric Ariston GL4S Electric 120 volts23.1 pounds
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How to Buy the Best Electric Tankless Water Heater: What to Look For

With a little bit of research, you can easily find the best electric tankless water heater for your needs. Here’s what you should look for.


The most important consideration you need to make when shopping for an electric tankless water heater is that of size. An improperly sized tankless water heater can result in too little water or the occasional cold shower – this is something that no person wants to deal with!

Figure out the flow rate necessary to service your home. All tankless manufacturers will provide sizing charts, which will let you know how much hot water can be delivered under ideal conditions. Figuring out your flow rate that is required along with your necessary temperature rise (which is based on the climate in which you live) will allow you to determine the appropriate size.

Incoming Water Temperature

While you can theoretically install an electric tankless water heater no matter where you live, you may be better off going for a traditional tank-style water heater if you live in a cold climate. This is because it can be difficult for a tankless water heater to produce a temperature rise of more than 30 degrees Fahrenheit with any kind of flow rate.

Otherwise, consider the climate in which you live and try to find a heater that is compatible with your environment.

Flow Rate

Flow rate is also an important consideration to make when you are buying an electric tankless water heater. While different units have different flow rates, it’s important to think about what you will actually be using the tankless water heater for before buying.

For instance, a bathroom sink is simply not going to use as much hot water as a continuously running appliance like a kitchen dishwasher, a shower, or a washing machine. If you plan on using hot water in one of these settings more often than another, you will need to adjust accordingly.


Many people opt for electric tankless water heaters for their size alone. Not only do these units take up much less space than their traditional tank counterparts, but they are also better for compact areas or settings in which they need to be portable – like for travelers.

The size of your unit is important but you also need to measure the place in which you intend to install it. If you plan on locating it in a tight spot like underneath a bathroom sink, you will need to get a smaller unit to conserve space. Just keep in mind that capacity will likely be diminished when you opt for a smaller tankless water heater, too.


When you are looking for an electric tankless water heater, choose one made out of durable materials. A traditional system uses metal, which will develop limescale over time. As a result, it will need annual maintenance.

In order for your system to work properly, you will need to have the limescale and other mineral deposits removed on an annual basis. Luckily, many modern tankless electric water heaters now use infrared technologies that build up less scale and require less maintenance. These are often sold at higher prices, but they may be worth the money when you consider the benefits.

Warm-Up Without Wasting Energy with the Best Electric Tankless Water Heater

1. Rheem Residential Tankless Water Heater

Rheem Residential Tankless Water Heater

Rheem is considered a leader in the industry when it comes to the best electric tankless water heater products. The RTEX-27 is no exception. This product has a user-friendly design and an attractive, minimalist appearance. It offers a powerful flow of hot water while allowing for energy efficiency up to 99.8%.

Offering up years of service, this tankless water heater has a ton of internal features to allow for one of the most comprehensive and best-performing units on the market. Before you purchase, take a look at Rheem’s guide. This will tell you the perfect size water heater you need to match your household needs and your geographic area.

Regardless of the option, you select, know that you will not be disappointed. The Rheem Residential Tankless Water Heater offers 4.0 gallons per minute at a 46 degree Fahrenheit temperature rise – it’s definitely one of the most powerful electric tankless water heaters you will find.

And the list of benefits doesn’t end there. This water heater can deliver up to 6.6 gallons per minute at peak performance. That’s enough hot water to provide heat to four showers and one sink all at once. The Rheem Residential Water Heater has an electronic temperature control with an easy to read display and advanced self-modulation so you can always meet your hot water demand.

What We Liked:

  • Can be wired for 208 or 240 v
  • Has three durable copper heating elements with brass tops
  • Has easy to read electronic temperature control

What We Didn’t Like:

  • Professional installation needed

2. Stiebel Eltron Tankless Water Heater

Stiebel Eltron Tankless Water Heater

One of the heaviest-hitting tankless water heaters you will find, the Stiebel Eltron is also one of the best electric tankless water heater options as a whole. Perfect for both residential as well as commercial users, the Stiebel Eltron is precision engineered for exceptional performance.

With a reputation for sound customer service and solid product manufacturing since 1924, this water heater is truly one of the best. It has a shiny housing that offers an attractive display as well as superior performance. Plus, the water heater comes with preset temperature memory buttons and an integrated flow meter to help you keep track of the water heater’s parameters.

The Stiebel Eltron even comes with an energy monitor that has you how much energy you are using – and also your cost savings. It allows you to adjust your temperature between 8 and 140 degrees to prevent scalding. You can even limit it at 109 degrees, which is particularly helpful if you have small children.

With self-modulation energy technology, the Tempra Plus is easy to use and easy to understand. It has a digital display bar with ten segments, each representing 10% to show you your power capacity.

Stiebel Eltron has an Advanced Flow Control Feature, too. This lets you set your output temperature and do nothing else, allowing the tankless water heater to do the work for you.

What We Liked:

  • Made out of superior materials
  • Does not have mechanical switches so it operates silently
  • Lasts more than 20 years in some cases

What We Didn’t Like:

  • Lower gallon per minute rate than similar units

3. Bosch Electric Tankless Water Heater

Bosch Electric Tankless Water Heater

Bosch is the name to know when it comes to the country’s top home appliances – and this electric tankless water heater is no exception. You don’t need a ton of space to heat up water with this convenient solution.

With the Bosch Tronic 6000C, you can easily heat up all the water your household needs without having to rely on gas. Designed to replace a 40-gallon electric tank water heater, this tankless water heater can achieve a flow rate of 3.5 gallons per minute, rising in temperature over 45 degrees Fahrenheit during this time.

With two solid copper heat exchangers along with brass fittings, the Bosch Tronic is truly built to last. It has a thermal cut-out switch that protects your heating elements from dry-firing as well as other various safety concerns.

This tankless water heater has a sleek, compact design that looks good and fits in just about anywhere. It has a built-in flow sensor along with polymer-encased elements that allow for consistent temperature output at all times. With a temperature range of 95 to 131 degrees, this modern, compact tankless water heaters ideal for installation in tight spaces.

What We Liked:

  • Perfect for installing in tight areas
  • Can be used to replace the Bosch Tronic 5000c WH27
  • Has a broad temperature range

What We Didn’t Like:

  • Has a higher activation flow than many other units

4. EcoSmart Eco 27 Electric Tankless Water Heater

EcoSmart Eco 27 Electric Tankless Water Heater

The name of this product truly says it all! When you are in the market for the best electric tankless water heater, you no doubt want one that is energy-efficient. One of the largest tankless water heaters you will find by EcoSmart, this tankless water heater is available in several sizes.

This water heater is not only well-made, but it’s also efficient. It can deliver 3.48 gallons per minute of hot water when your incoming water temperature is 52 degrees. Like many of the other electric tankless water heaters we have reviewed, this product has self-modulating technology so that you can adjust the amount of energy used to the amount of hot water you need. This helps you operate efficiently and quickly.

With a 99.8% efficiency rating, this electric tankless water heater even comes with thermal auto protection. You don’t have to worry about the unit overloading or overheating. It has an easy-to-follow digital interface that delivers temperature adjustments up to one degree. With a temperature range between 80 and 140 degrees, this unit is one you’ve got to consider for your own home.

What We Liked:

  • Offers the ability to finely tune your temperature adjustments
  • Has copper and stainless steel components
  • Intuitive digital interface

What We Didn’t Like:

  • Must be professionally installed to qualify for a limited lifetime warranty

5. AB WiseWater Tankless Instant Water Heater

AB WiseWater Tankless Instant Water Heater

The AB WiseWater Tankless Instant Water Heater is a great option for people who want an energy-efficient water heater that can hold up to the pressures of any home. It provides unlimited hot water when and where you need it, without requiring you to spend a ton of money on installation.

Measuring just 19×14.5×5.5 inches, this product weighs less than 15 pounds and can be wall-mounted. It can reach temperatures of 125 degrees Fahrenheit, which is perfect for showering. It allows you to save up to 50% on your energy expenses, as it is highly energy efficient.

With a flow rate of three gallons per minute, this unit allows you to get enough hot water even while other devices are in use. It is easy to install at the point of use, including the kitchen or bathroom and is highly attractive.

With electricity leakage protection and an LED temperature control display, this wall-mounted unit has everything you could ever want for a unit inside your home. It even comes with scalding protection, overheating protection, and overpressure protection. As a result, it is both ETL listed and NSF certified for safety.

What We Liked:

  • Can be installed just about anywhere
  • Compact and attractive
  • Energy-efficient product

What We Didn’t Like:

  • Maximum temperature of 125 may not be warm enough for everybody

6. iHeat Tankless S-14 240V 59A 14KW Electric Water Heater

iHeat Tankless S-14 240V 59A 14KW

The name here truly says it all – the iHeat is a water heating machine!

The iHeat Tankless Electric Water Heater weighs less than eight pounds yet has a flow rate of two gallons per minute. It has a temperature range of 32 degrees Fahrenheit to 105 degrees Fahrenheit, a massive range that allows it to heat up quickly no matter where you live.

With a waterproof interactive touchpad, the device is easy to use and perfect for cabins, beachfront properties, kitchens, bathrooms, or even commercial properties. It allows you to enjoy multiple back-to-back showers in your household and is made out of lightweight yet durable stainless steel.

A compact, easy to install model, this product can be installed directly at the point of use. Temperatures can easily be controlled with the touchpad, too.

With a stylish, energy-efficient design, this product can be installed by just about anyone. It is also covered by generous manufacturer warranties.

What We Liked:

  • Has a durable stainless steel construction
  • Highly energy efficient
  • Perfect for installing anywhere in the home

What We Didn’t Like:

  • Has a relatively low flow rate

7. Marey ECO150 220V/240V-14.6kW Tankless Water Heater

Marey ECO150 220V240V-14.6kW

The Marey Eco 150 is another top energy-efficient tankless water heater. Ideal for a two-bathroom home, this compact and lightweight unit can be installed directly at the point of use – it will work almost immediately.

With a unique activation mechanism that allows you to produce hot water even with a low pressure of low rate, this tankless water heater has a smart control technology that allows you to adjust your temperature with ease. It also allows you to optimize energy use, giving you full control of the temperature along with the safety features to prevent overheating and scalding.

The Marey Tankless Water Heater has a smart control LCD panel display and is ETL approved. It’s backed by a five-year manufacturer’s warranty and is powerful enough to work on multiple points at once.

What We Liked:

  • Has smart technology temperature control
  • Energy-efficient product
  • Comes with a five-year warranty from the manufacturer

What We Didn’t Like:

  • Some customers report leakage from the back of the unit

8. ECOTOUCH Electric Tankless Water Heater Point-of-Use Hot Water Heater

ECOTOUCH Electric Tankless Water Heater

Another tankless water heater for you to consider is the Ecotouch Electric Tankless Water Heater. A point of use heater, this electric product has a 5.5kW heating system that supplies users with endless hot water that is consistently 116 degrees Fahrenheit or higher.

You won’t need to wait for the water to preheat – nor will you need to adjust it – when you use this heater. It also comes with smart self-adjustment so that it can adjust its power based on the flow rate of the water along with its temperature setting. This is all done in real-time, too!

When your water flow drops off, the heater will automatically apply less power. You won’t have to worry about adjusting the temperature or energy usage yourself because the heater will do it automatically. With a smart self-adjustment system, this electric water heater has everything you could ever want – and more.

What We Liked:

  • Has a digital display and touch control panel
  • Avoids scale build-up and leakage
  • Extremely compact and attractive

What We Didn’t Like:

  • Pressure drops significantly every now and then

9. Atmor AT-D18TP-AZ Thermopro

Atmor AT-D18TP-AZ Thermopro

One of the newest electric tankless water heaters on the market, the Atmor Thermopro is also one of the best electric tankless water heaters for those who are budget-conscious.

It has a ton of beneficial features and is incredibly safe. It can be installed near showers and sinks since it is 100% splash-proof. It also has Smart Flow technology so that it can supply unlimited hot water without decreasing the temperature.

In addition to providing a limitless water flow, the Smart Flow technology makes it possible for you to save money and energy. It only turns on when you turn the hot water faucet on so that the heating mechanism is not sitting idle when it doesn’t need to be in use. With self-modulating technology, this water heater can reduce your energy bills as it regulates how much energy is needed to heat the water.

What We Liked:

  • Comes with splash-proof certification
  • Comes with a digital temperature control panel
  • Incredibly easy to install and user-friendly

What We Didn’t Like:

  • Has a maximum water output of only 3.7 GPM

10. Ariston GL4S Electric Mini-Tank Water Heater

Ariston GL4S Electric Mini-Tank Water Heater

Another one of the best electric tankless water heaters is also one of the tiniest. If you don’t have a ton of space in which to house your water heater, then this product can fit the bill. Easy to use with a plug and play operation, this heater can be installed just about anywhere.

Furthermore, it can be connected directly to a shower, faucet, dishwasher, or even the kitchen sink. It gives you plenty of water on demand which can save on plumbing and operation costs. You don’t need to hire a plumber to install your heater – you can do everything all on your own.

With a maximum water output of 4 gallons per minute, this unit’s point of use system is easy to operate and incredibly efficient. It’s a great value with its plug and play design and is even backed by a six-year manufacturer’s warranty that allows for an equal exchange.

What We Liked:

  • Easy to install and to operate
  • Can be connected to a faucet
  • Backed by a manufacturer’s warranty

What We Didn’t Like:

  • Does not allow for incremental temperature changes

What are the Benefits of an Electric Tankless Water Heater?

Trying to decide whether an electric tankless water heater is worth your money? There are several advantages that a tankless water heater presents over a tank-style water heater.

For one, a tankless heater offers an endless stream of hot water when you have sized it correctly. A conventional heater, on the other hand, will be limited by the tank size. Tankless water heaters take up less space since they are mounted on the wall. They offer significant energy savings since they aren’t continuously running like tank-style water heaters are.

While you might find that tankless water heaters are slightly more expensive to purchase and install upfront than traditional tank-style heaters, you will likely find that the investment is well worth the cost. They are designed to last almost twice as long as regular water heaters and offer you unparalleled peace of mind and comfort.

So what are you waiting for? Get out there and get shopping for one of the best electric tankless water heaters today.

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