Reviews of The Best Electric Tankless Water Heaters of 2019

Published by Alexa Bartel on

Electric Tankless Water Heater Reviews

Did you know that a hot water tank could easily account for almost 25% of a family of four’s energy bill? That is more than the air conditioning and other appliances combined.

This is why many Americans are making the switch from a traditional hot water tank to a point of use or on-demand electric tankless water heater.

There are several benefits to using an electric tankless water heater. Not the least of which are big monthly electricity savings, cheaper up-front costs as well as ease of installation.

In general, electric tankless water heaters are used under a sink or for single appliance use. If you need a tankless water heater for your whole home, we recommend looking at a gas powered unit. You can find lots of information by checking out our Tankless Water Heater Buying Guide.

There are many different electric tankless water heater models to choose from to suit specific needs. Check out our tankless water heaters reviews to learn more and find the right make and model for your needs. 

Electric Tankless Water Heater Comparison Chart

  • The most powerful water heater in the market
  • Advanced flow control for enhanced savings
  • Compact design fits almost anywhere
  • Advanced flow control for enhanced savings
  • Compact design fits almost anywhere
  • Runs 100% silent with no mechanical switches
  • Industry leading brand in hot water heaters
  • One of the best warranties in the business
  • Adequate flow rate at 3.0 – 3.5 GPM
  • Non-Metallic material requires no maintenance
  • Beautifully designed
  • Environmentally free
  • A lot of power in a small package
  • Backed by industry leading brand
  • Great for cabins and cottages
  • Highly energy efficient (save 50%)
  • Adjustable LED Display Temperature Controls
  • Great safety features
  • Durable Stainless Steel design
  • Energy-efficient Temperature Adjustment
  • 1, 3. 5 yr Warranty
  • Easy to install
  • Adequate 3.5GPM Flow Rate
  • Economically priced
  • Smart-enabled Temperature Control
  • Great for 2-bathroom household
  • 5 yr warranty

The following units have earned our top reviews of the best electric tankless water heaters in each category.

Stiebel Eltron’s flagship product, the Tempra Plus, has some of the very best electric tankless water heater reviews in the market. With one of the highest GPM flow rates available at 4.0 GPM with the ability to raise the temperature 50F. This is by a wide margin, the best performance you can expect from an electric tankless water heater.

We also love that even though this unit is the most powerful you can find, it is not much more expensive than a unit half its size. And that makes it all the worthwhile when paired with the advanced flow control, which we’ll explain.

The Tempra Plus is one of the only units to also have advanced flow control. You can limit the amount of flow when it’s not required, resulting in even more energy savings. Think of it as Eco Mode for your water heater. For more information on advanced flow control, have a look at this short video:

While this unit is the most powerful you will find in electric tankless, it is not powerful enough to provide hot water to an entire home. We would recommend installing a unit in each room that requires hot water. It is powerful enough to run a shower and a bathroom sink; a washing machine and laundry sink or a dishwasher and a kitchen sink.


  • The most powerful water heater in the market
  • Advanced flow control for enhanced savings
  • Compact design fits almost anywhere
  • Runs 100% silent with no mechanical switches


  • Slightly more expensive than heaters
  • Design isn’t elegant; you’ll want to hide the unit

The bottom line: If you want the best electric tankless water heater available, and don’t mind spending a few extra bucks, this is the unit for you.

The EcoSmart ECO is a close second among our top electric tankless water heater reviews. The top model (Eco 36) has one of the best GPM flow rates available at an impressive 3.5 GPM with a temperature rise of 40F. While not as powerful as the Tempra Plus, this unit is generally sufficient to provide hot water to an entire room, such as a kitchen, bathroom or laundry room.

If you are looking to power your entire house with the EcoSmart ECO line, you will need to purchase several units, ideally one for each room.

As you’ll see with the rest of the tankless water heaters, both the EcoSmart ECO and the Tempra Plus are in their own class. Their performance is roughly similar and sufficient for any’s room needs. What we prefer about the EcoSmart is the design, it is the clear winner in terms of visual appearance. If you need to place this in a laundry room, it will have an elegant and modern feel even if the water heater is exposed.


  • The most powerful water heater on the market
  • Advanced flow control for enhanced savings
  • Compact design fits almost anywhere
  • Runs 100% silent with no mechanical switches


  • Slightly more expensive than heaters
  • Design isn’t elegant; you’ll want to hide the unit

The bottom line: If you want a powerful and beautiful electric tankless water heater, this is the unit for you.

Rheem continues to be an industry leader in hot water heaters, from commercial grade tanks to residential electric tankless. Their top electric model, the Rheem RTEX-18 offers some of the best value in water heating. On top of the peace of mind you get when buying from a company that has been around for decades, you get most of the features available from premium models at a lower price. The premium brands usually cost more, but in electric tankless water heating you can get the big brand for less.

Rheem claims this unit can provide 4.4 GPM of hot water flow, but in real-world tests with cold incoming water, we have found 3.0 – 3.5 GPM is more reasonable to expect. Of course, 3.5 GPM is a sufficient flow rate to power the hot water needs of most any room in the house.

The challenge is that it may take up too much space under a sink. In addition, it isn’t the most visually appealing unit either. But these might not be factors for you, if you have lots of hidden space to place the unit.


  • Industry-leading brand in hot water heaters
  • One of the best warranties in the business
  • Adequate flow rate at 3.0 – 3.5 GPM
  • 99.6% energy efficiency
  • Great price


  • Larger than most units, not suitable for small spaces
  • Does make some noise, although it’s not loud

The bottom line: If you want good value and a good brand for an affordable price, this unit is for you.

Best Infrared: SioGreen IR8000

If you live in an area with particularly hard water, or you are looking for a water heater for an RV or tiny home, you should consider the SioGreen IR8000.

This electric tankless water heater was made with non-metallic materials, meaning limescale doesn’t build up in the unit. This is one of the only heaters in the market that doesn’t require any maintenance thanks to this innovative technology.

Of course, this tremendous advantage is not without its downside. The SioGreen IR8000 isn’t capable of very high flow rates at a 50F temperature rise. It is definitely best suited in late spring to early autumn or in warm climates that don’t require a high-temperature rise.

Infrared technology in tankless water heating is a relatively new technology and we expect to see improvements over the coming years as the maintenance aspect of going tankless can be an issue for many people.

It is also worth noting that this water heater is visually appealing and looks as high-tech as it is. This water heater is advertised as a whole house electric tankless water heater, but we think you’d be disappointed with a single unit for an entire house.


  • Non-Metallic material requires no maintenance
  • Beautifully designed
  • 99% energy efficient


  • Not as powerful as other units available for the same price
  • Somewhat expensive for the value

The bottom line: If you don’t want to bother with annual maintenance and don’t require a lot of power, this unit is for you.

Rounding out our list of the top electric tankless water heater reviews is the Bosch Electric Tankless. A compact, highly efficient unit that uses very little energy and it is backed by a premium brand.

This could be exactly what you need if you have very modest water heating needs. If you are looking for a simple water heater to install in your summertime cabin or cottage for a small bathroom, this is the perfect water heater. For less than $200, you can enjoy hot water just like at home!

It would also be suitable for providing hot water to a sink. Anything more than that and this will prove to be insufficient. That said, there is no need to spend a lot of money on a water heater if your needs are modest.


  • A lot of power in a small package
  • Backed by industry-leading brand
  • Great for cabins and cottages


  • Not powerful enough for cold incoming water temperatures
  • A little louder than we’d prefer

The bottom line: If you want a small, simple and affordable water heater for the summertime, this is the perfect unit for you.

Key Features:

  • Product Dimensions: 19 x 14.5 x 5.5 inches
  • Weight: 14.6 lbs
  • GPM: 3
  • Temperature Range: 86-125F
  • Electricity Leakage Protection
  • LED Temperature Control Display
  • Scalding Protection
  • Over-pressure and overheating Protection
  • ETL listed
  • NSF Certified

Best Suited For: Kitchen, bathroom, Cabin, Studio, 1 bedroom apartment

AB WiseWater’s Tankless Instant Water Heater isn’t a premium grade water heater but it works well enough to provide unlimited hot water when you need it.

The temperature range on this wall-mounted unit reaches a peak of 125F, which may not be as hot as you’d like for a shower or even a cup of coffee. It’s economically priced, however, and fairly easy to install.

Properly installed, the AB WiseWater Tankless Heater is quite energy efficient and can save you up to 50% on your energy bill. 3 GPM is high enough to provide a steady flow of hot (or warm) water even while other water devices are being used. You’ll be able to enjoy a hot shower on demand without waiting for your tank to replenish.

Install and use this model at the point of use (bathroom, kitchen, etc) and you’ll have all the hot water you need for years to come.

  • Economical
  • Energy efficient (save 50% on energy)
  • Compact size requires little space
  • Low GPM
  • Cannot be installed for outdoor use
  • Heats water to a warm 125 degrees F but not hot
  • No warranty information

Key Features:

– Product Dimensions: 3.5 x 7.7 x 11.5 inches
– Weight: 7.5 lbs
– 2 GPM Maximum
– Temperature Range: 32 degrees F – 105 degrees F
– Waterproof interactive touchpad
– Up to 60% Energy Savings
– Warranty: 1 yr Elements limited 3-Year Components 5-yr leaks

Best Suited For: Beachfront properties, Cabin Resort, Kitchen, Bathroom, Hospital, Commercial property

You can finally enjoy back-to-back hot showers without running out of hot water in your busy household.If you need an electric tankless water heater for your beachfront property, bathroom, kitchen, or even your yacht, the iHeat Stainless Steel is a dream come true.

The iHeat Tankless Water Heater is a compact wall-mounted unit made of durable stainless steel. While it’s lightweight, compact and pretty easy to instal, you may require copper piping and adapters to install it. Once installed at the point of use (ie your kitchen sink, shower, etc) the iHeat provides unlimited hot water on demand, to a peak of 105 degrees C. You can control the temperature setting, beginning at the default setting of 32 degrees.

Admittedly, the 2GPM is lower than many of the electric tankless heaters in our review, but you’ll still enjoy on-demand hot water. Its energy-efficient design can also save you up to 60% on your energy bill.

The best part about the iHeat is that it can be installed and used for any number of applications. As we mentioned, it’s small and weighs only 8 lbs. The waterproof touchpad prevents shorting out, among other safety features, and the iHeat is covered by generous warranties for the element, components and against leaks.

Some users warn that this unit may stop working effectively after 6 – 12 months of use.

  • Durable Stainless Steel construction
  • Energy efficient (save up to 60%)
  • Warranty includes heating element, components and leakage
  • Low GPM not suited for whole house application
  • May malfunction after 6 – 12 months

Key Features:

  • Product Dimensions:17 x 14 x 3.8 inches
  • Weight: 14.5 lbs
  • 3.5 GPM Max
  • Temperature range:  80°F to 140°F
  • 5 yr Warranty for leaks, 1 yr for parts

Best Suited For: Kitchen, Bathroom, Studio, 1 bathroom apartment or home, Office


Enjoy a limitless stream of hot water on demand in your home with this stylish, sophisticated electric water heater!

The Eemax EEM24018 is a step up from some of the more economical tankless water heaters we’ve reviewed. What really makes it unique is the self-modulating technology, which regulates energy output based on our need.

picture of Eemax EEM24018 Electric Tankless Water Heater, Blue product power requirements for installation

This highly energy-efficient unit also has a higher temperature range that reaches a peak of 140F. You can adjust the temperature in increments of 1 degree, which gives you even more control.

Economical, stylish and energy-efficient, the EEMAX is an incredible bargain that delivers unlimited hot water once it reaches the activation point. You might want to purchase more than one because it works so well!

  • Adequate 3.5 GPM
  • Adjustable temperature control
  • Easy to install
  • Highly energy-efficient
  • Not designed for whole house use
  • Slight delay before unit reaches activation point

Key Features:

  • Product Dimensions:8.7 x 3.5 x 14.2 inches
  • Weight: 10.1 lbs 
  • 2.5 GPM 
  • ETL approved
  • Smart Control LCD Panel Display
  • 5 yr Warranty

Best Suited For: 1 -2 Bathroom Household


The Marey ECO150 is a premium quality, energy-efficient tankless water heater for households with 1 – 2 bathrooms. Compact, and lightweight, you can install it at the point of use and it will work almost instantly. The activation mechanism can produce hot water even when the water pressure and flow rate is as low as .5Gpm/5Psi.

Because of its smart control technology, you can easily adjust the temperature and optimize your energy use. The LED Display gives you control of the temperature, along with safety features to prevent scalding or overheating.

diagram of Marey ECO Tankless Water Heater with Smart Technology

Some users have experienced water leakage from the back of the unit. It also requires requires 1 x 70 amp double pole breaker to work effectively. Luckily, there is a 5 year warranty included. with your purchase.

 Powerful enough to work on up to points of use simultaneously, the Marey ECO150 is an affordable tankless water heater. You’ll have hot water on demand for your whole family at a price you can afford!

  • Smart Technology Temperature Control
  • Energy efficient
  • 5 yr warranty
  • Economical
  • May experience leakage from the back of the unit

What Are Electric Tankless Water Heaters?

Electric tankless water heaters heat water directly. When hot water is turned on, cold water travels through a pipe into the unit, and the electrical element heats the water. With tankless water heaters, there is a continuous supply of hot water to showers, dishwashers and washing machines.

We love that tankless water heaters don’t produce standby energy losses, as opposed to traditional storage water heaters. This saves you lots of money in the long run!

Benefits of Electric Tankless Water Heaters:

● More affordable to install than gas tankless
● Versatile installation: indoor & outdoor
● Additional storage space
● Doesn’t produce greenhouse gases
● Uses less energy
● Lasts longer than tank heaters
● Lower energy bills
● You’ll never run out of hot water
● Could even improve the resale value of your home

When to Use a Tankless Electric Water Heater

The two key benefits of moving to this technology are:

1) A huge space saver, and…

2) A huge energy saver.

Here are a few situations where you may find them particularly useful:

A Guesthouse or Pool House

You have a compact space, to begin with. So, everything in these rooms needs to be the miniature version of what you would put inside your home. You probably already have a mini bar fridge, smaller furniture, and most likely a small 2-piece bathroom.

A tankless electric water heater works magically in these spaces, as it gives you access to hot water, without having to give up the equivalent of an entire closet space for a traditional 50-60 gallon water tank.

But, if you add a shower into the mix, you will want a whole house electric tankless water heater. More on that later.

A Cabin, Vacation Home, Lake House or Cottage

Do you have a cozy little retreat that you use over the warmer months? This could be the perfect solution, depending on the amount of family, friends, and guests you expect to stay over.

Your standard tankless electric water heater unit is perfect to keep your sinks and faucets running hot water. However, if you’re looking at showers and bathtubs, you’re going to want to explore whole house electric tankless water heater options.

A lot of vacationers love these units when it comes to close up shop for the season and winterize the home. A traditional water tank takes forever to drain (to prevent freezing), whereas a tankless heater is drained in a few seconds.

When Not to Use a Tankless Electric Water Heater

These are perfect in a lot of situations… But, not all of them. You should definitely keep a tankless water heater’s restrictions in mind in any of the following situations.

Back-to-Back Showers For the Whole Family

Most of the models out there are not really for use to supply hot water for a shower or bathtub. This is particularly true for a family home where multiple people will be taking a shower, often one right after another to get ready in the morning.

Hot water is already a precious enough commodity in the morning and this is asking too much of most of these systems.

Dishwashers and Washing Machines

Next to the shower or bathtub, your dishwasher and washing machine are going to be the biggest drains on the hot water in your home.

If your dishwasher has a heating element built into it, you can likely go tankless for this kitchen. However, if that’s not the case, you could struggle to get the water warm enough and put way too much pressure on the unit.

Meanwhile, some modern front-loading washing machines are built with tankless heaters in mind, so they can operate in a good range of efficiency. However, you need to be absolutely positive that you buy the right unit. Not all modern washers are built this way, even if they’re energy-efficient and boast how little water they use.

Any time you are looking to add appliances into the mix, odds are good you need a whole house electric tankless water heater.

Solar-Powered Homes

Just to be clear about exactly what we’re talking about here. There are solar water heaters available on the market today and they certainly have their place. But, right now, we’re talking about trying to use a tankless water heater in a solar-powered home

If you have (or you’re building) a solar-powered home, you’re already aware of the fact that you need to be mindful of the usage and efficiency of all your appliances, and how much demand you’re putting on your home’s own little power grid.

As of right now, it’s not really possible to heat the water with a solar thermal panel. So look into other options.

Cold Environments and Climates

If you’re living in a colder or more northern community and pipes freezing are an issue that you have to think about every year, you need to be very careful how and when you use a tankless water heater.

You especially need to think twice about keeping the unit outside or in poorly insulated/ poorly heated rooms.

Electric Tankless Water Heaters: Buying Considerations

There are several factors that need to be considered before you purchase an electric tankless water heater, which we’ve outlined below.

Incoming Water Temperature

Electric water heaters work best when they don’t need to raise the temperature more than 30 F. Even the most powerful units aren’t capable of producing a temperature rise of 50 F with any reasonable flow rate. If you live in the Northern United States or Canada, you may want to consider buying a hot water tank, or opting for a gas powered unit that is capable of a higher temperature rise. If you live in the Southern United States or plan to use the heater during spring and summer months, an electric unit can be the perfect choice.

average incoming water temperatures in the united states

If you live in the blue zone, you should consider a gas powered tankless water heater

Flow Rate Needs

Different appliances and faucets require different amounts of water. For example, a bathroom sink will use far less hot water than a washing machine or a dishwasher. Electric tankless water heaters will be rated in terms of their flow rates, and it’s an important factor when deciding which unit to buy. In general, the higher the flow rate, the more expensive the unit and the more electricity it will use.

Demand TypeSize
Bathroom Sink0.5 GPM
Standard Shower2.5 GPM
Low-Flow Shower1.5 GPM
Dishwasher1.0 GPM
Washing Machine1.5 GPM
Kitchen Sink0.5 GPM
Laundry Sink1.0 GPM


These water heaters come in a variety of sizes, and it’s important that you measure the space you plan to install the unit, before you purchase. In especially tight spaces such as under a kitchen or bathroom sink, you may need to opt for a smaller unit to preserve space.

Materials Used

Most traditional tankless water heaters use metal materials that will build up limescale and require annual maintenance. However, there are newer technologies being used, such as infrared, that build up much less scale and require less maintenance, but for a higher price and generally smaller flow rates. Depending on how hard the incoming water is, you may want to opt for an infrared unit that will require far less maintenance and won’t be likely to break down

Tankless Water Heater Installation

Is this something the average DIYer can tackle? Maybe, but this is a pretty advanced process. Also, gas tankless water heater installation is best left to professionals.

However, electric tankless water heater installation is doable, if you’ve worked with plumbing and electrical systems before. You should also have a strong background in carpentry to frame and box the actual unit.

You will also need access to the following tools and materials:

  • Spade drill bits
  • A power drill
  • Adjustable wrenches
  • A screwdriver set
  • A torch kit and solder
  • A reciprocating saw
  • A hand saw
  • Black pipe
  • Caulk
  • Pressure treated lumber
  • Metal ducts
  • Pipe insulation

Your best bet is to probably watch a few electric tankless water heater installation videos on YouTube or home improvement sites to see the steps and decide if this is something that is truly within your comfort zone.

If not, your best bet is to call in a professional.

How to Take Care of Your Tankless Electric Water Heater

Like any appliance or major purchase for your home, the life you get out of your tankless heater will depend on the TLC and ongoing maintenance you give it over the years.

A well-maintained unit will operate at maximum efficiency over a long period of years. However, a neglected unit will see its interior eroded and clogged with mineral deposits, which will make it work much harder than it should and greatly shorten its lifespan.

Let’s take a look at how to maintain and care for your unit. These steps should be done about once every year, and they are an absolute must if you’re in an area with hard water.

Step 1. Safety First

The first step is to make sure everything can be done safely and turning off the power from the breaker in your fuse box.

Step 2: Close the Valves

Next, you will want to turn off the 3 water valves attached to this unit. You should see:

  1. The cold water valve (most likely blue)
  2. The hot water valve (most likely red)
  3. The main valve that runs the water into your home.

Make sure all 3 are closed.

Step 3: Purge the Pressure

Remove the caps slowly from the purge valves on the cold and hot water valves using the t-shaped handles.

This is why the previous step was so important, because you need to make sure the hot water valve is shut tightly. Ensure that the rubber washers are in place.

Step 4: Attach the Hosing Lines

You might need to check the unit’s manual for specific instructions to do this properly. You might even need a sump pump and connect hoses that will flush the water from the unit using the cold and hot water valves.

If your heater didn’t come with hosing lines, you can buy them at most hardware or plumbing supply stores. Your lines need to be long enough to comfortably extend between your unit and your bucket.

Step 5: Open the Purge Port Valves

Twist them perpendicularly to the cold and hot valves.

Step 6: Use a Safe Cleaner to Flush

This tankless water heater is most likely going to be the source of your family’s water. Make sure you’re not using any toxic or harsh cleaners to clean the pipes within the unit. Consider 2.5 gallons (9.46 liters) of undiluted white