Best Electric Tankless Water Heater Reviews for 2019(Bosch, Rheem, and More)

best electric tankless water heater

Electric tankless water heaters, also referred to as on demand water heaters, have become extremely popular in recent years. The best electric tankless water heater will save energy and heat water even in the cold winters.

This is in large part due to the money saving advantages they can offer homeowners. The special technology used in electric tankless water heaters can save you hundreds, or in some cases thousands, over the course of several years.

If you are in the market for an electric tankless water heater you have come to the right place. If you are looking for the best gas tankless water heater for your home you can check our buyers guide here.

Below we are going to break down everything you need to know about investing in an electric tankless water heater.

After reading this guide you will be well informed and able to make a smart buying decision.

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Electric Tankless Water Heater Comparison Table

Top 5 Electric Tankless Water Heaters:

1) EcoSmart ECO 27 Electric Tankless Water Heater

EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology
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If you live in the Northern United States where incoming water temperatures can be as low as 37°F, the EcoSmart ECO 27 Electric Tankless Water Heater is a great option for your home.

It is indeed one of the largest tankless water heaters currently on the market that uses the EcoSmart patented self modulating technology.

The EcoSmart ECO 27 is capable of heating close to 3 gallons of water per minute at very low temperatures.

It can supply plenty of hot water for up to two showers running at the same time while keeping your energy bill nice and low.

If you live in the southern parts of the United States this water heater will be able to handle up to 6 gallons of water per minute.

That means you will be able to run four showers and a sink at the same time without worrying about running out of hot water.

Using the digital temperature control you can set the temperature between 80°F – 140°F. You are able to make adjustments in 1 degree increments using the control.

The EcoSmart ECO 27 only turns on when hot water is needed. Because of this you are able to save up to 50% on your water heating costs.

Pros of this tankless water heater

  • Compact in size which means you save space
  • Can help you save as much as 50% on water heating costs
  • Features a digital temperature control
  • Uses advanced modulating technology to help you save energy

Cons of this tankless water heater

  • Many users have complained about the life span of this water heater.
  • Several have said it didn’t last much more than a year.

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EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology
  • Savings of up to 50% on water heating costs. Dimensions :17H...
  • Digital temperature control in 1-degree increments allows...
  • Copper and stainless components designed for efficiency,...

2) Stiebel Eltron Tempra Plus 24 kW

Stiebel Eltron 224199 240V, 1 Phase, 50/60 Hz, 24 kW Tempra 24 Plus Whole House Tankless Electric Water Heater, Advanced Flow Control
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Of all the tankless water heaters on the market, the Stiebel Eltron Tempra Plus 24 kW is easily the most technologically advanced.

The Tempra series has been completely redesigned and is now considered the next generation of German quality.

Some of the upgrades you will find on the Stiebel Eltron Tempra Plus 24 kW include upgraded heavy-duty electronics, a simple single flow sensor design, a hinged cover for easy access, and Advanced Flow Control.

This particular water heater was designed to replace your old water heater tank without interfering with your current hot water needs.

On average you can expect to save between 15%-20% kWH when you have the Stiebel Eltron Tempra Plus 24 kW installed at your home.

To adjust the temperature of the water simply turn the dial to your desired temp. And don’t worry, this water heater is very small and will take up very little space.

There are two key advantages to using this particular Tempra over a tankless water heater that uses gas instead of electricity.

The first advantage is of course price. It is a lot less expensive to purchase the Stiebel Eltron Tempra Plus 24 kW versus a similar model that uses gas.

The second advantage is how easy it is to install. Being that there is no vent necessary the installation process is a lot less complicated than other water heaters.

Pros

  • Digital temperature control for easy temperature adjustments
  • No venting required which makes installation quick and easy
  • Proven to be reliable
  • Sleek design making it the perfect fit for any location
  • Can save you up to 20% on the hot water portion of your electric bill
  • 7 year leakage warranty and 3 year parts warranty

Cons

  • Not durable.
  • Many customers have complained about the unit not working after a few months.

3) Bosch Tronic 3000 T 4-Gallon Electric Mini-Tank Water Heater

Bosch Electric Mini-Tank Water Heater Tronic 3000 T 4-Gallon (ES4)  - Eliminate Time for Hot Water - Shelf, Wall or Floor Mounted
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With the with the Bosch ES4 Tronic 3000 T 4-Gallon Electric water heater you will get access to hot water where you need it, when you need it.

No more waiting for hot water from a sink that isn’t located close enough to the primary heating source.

The great thing about the Bosch ES4 Tronic 3000 T 4-Gallon Electric water heater is that it can be used for three different applications.

You can either use it to heat water for a single tank, as a supplement for an existing water heater or as a buffer for tankless water heaters that often deal with intermittent cold water.

To ensure maximum energy efficiency the system is insulated using thick CFC-free foam insulation.

To ensure durability the tank is lined with glass and comes with a 6 year limited warranty on the inner tank. There is also a 2 year limited warranty on other components of the system.

This particular unit is compact and lightweight which makes it perfect for small spaces. It can be placed on the floor, on a shelf or mounted to a wall.

Its sleek and very attractive design means it can blend in with just about any type of decor.

Pros of this tankless water heater

  • Small and compact. Fits just about anywhere.
  • Easy to maintain.
  • Glass lined tank that extends the life of the unit.
  • Versatile
  • Fast recovery rate which means there is no long wait for hot water.
  • Very affordable. Will cost you less than $200.

Cons of this tankless water heater

  • Multiple customers have complained about the unit leaking.

Bosch Electric Mini-Tank Water Heater Tronic 3000 T 4-Gallon (ES4) - Eliminate Time for Hot Water - Shelf, Wall or Floor Mounted
  • CONVENIENT HOT WATER HEATER: 4 gallon point-of-use mini-tank...
  • LONG LASTING QUALITY: This electric water heater is easy to...
  • INDEPENDENT INSTALLATION: 36-37" cord plugs into a 120 volt...

4) Rheem RTEX-18 240V 2 Heating Chambers Residential Tankless Water Heater

Rheem 240V 2 Heating Chambers RTEX-18 Residential Tankless Water Heater, small, GREY
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If you want a water heater that can heat water in an instant you will absolutely love the Rheem RTEX-18 240V 2 Heating Chambers Residential Tankless Water Heater.

It has the ability to provide a continuous flow of hot water quick and on demand. It can be used for single point of use or with multiple applications.

It features an external digital thermostatic control with LED display so you can set the temperature to whatever you like.

And while many tankless water heaters feature a self modulation system,  the Rheem RTEX-18 240V 2 Heating Chambers Residential Tankless Water Heater features one of the most advanced.

With it you are able to adjust the power to meet your hot water demands.

This unit is threaded which makes installation simple and replacement easy.

Pros

  • External digital thermostatic control for easy temperature adjustment.
  • Simple installation
  • Provides continuous hot water quick and on demand

Cons

  • Some users have complained about the durability of the unit.

Rheem 240V 2 Heating Chambers RTEX-18 Residential Tankless Water Heater, small, GREY
  • External digital thermostatic control with LED display (+/1...
  • Most advanced self-modulation, adjust power to meet hot...
  • Durable Copper immersion two heating elements, field...

5) SioGreen IR288 POU 220v/10A-40A/2kW-9kW Infrared Electric Hot Tankless Water Heater

Sio Green IR288 POU Infrared Electric Tankless Water Heater 240v / 40A / 9kW
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When the engineers at SioGreen created the SioGreen IR288 POU 220v/10A-40A/2kW-9kW Infrared Electric Hot Tankless Water Heater, they did so with the intention of making it like no other on the market.

Needless to say they succeeded

They started by using a non metallic heating tube that is resistant to corrosion and hard water deposit build ups.

This special tubing also has the ability to inject heating BTU’s into the water as it passes through the heat exchanger.

For media they opted to use Quartz.

The great thing about Quartz is it is in abundant supply all over the world. It is also recyclable which means it is great for the environment.

To contain the Far-infrared energy there is a patented coating applied to the outside of the Quartz. This is what causes the cold water to be heated as it passes through the chambers.

The SioGreen IR288 POU 220v/10A-40A/2kW-9kW Infrared Electric Hot Tankless Water Heater was designed to operate in either automatic mode or manual mode.

When in automatic mode smart modulating technology is used to quickly calculate the difference between the current temperature and your desired temperature.

The software will then predict how much power is needed to reach and maintain your desired temperature.

In manual mode you will need to make all adjustments manually. To turn on manual mode hold down the power button for 3 seconds.

Once in manual mode you will be able to adjust the power to 8 different levels between 1 and 8. You will also be able to adjust the current from 5-40 amps.

The SioGreen IR288 POU 220v/10A-40A/2kW-9kW is not much bigger than a shoebox which means it will save you a great deal of space.

It is small enough to fit under the smallest of cabinets and can easily be installed in a utility room, kitchen or bathroom.

While it is great for homes, it is also a great fit for apartments, businesses and industrial buildings.

Pros

  • Coil-less technology used to energize the water
  • Corrosion free
  • Maintenance free
  • No calcium and limescale deposits
  • Helps you save water and energy by only using the power needed to heat the water
  • Units of this caliber usually cost over $500. This one will run you less than $400.

Cons

  • Many users have complained about it no longer working after a few months.

Sio Green IR288 POU Infrared Electric Tankless Water Heater 240v / 40A / 9kW
  • HOT WATER ANYTIME YOU WANT WITHOUT ANY HASSLE! The Sio Green...
  • PATENTED TECHNOLOGY, NO COIL METALLIC ELEMENTS, NO...
  • 100% SATISFACTION OR YOUR MONEY BACK! That's our...

Electric Tankless Water Heaters vs Traditional Water Heaters

To get things started let’s quickly discuss a few of the differences between a traditional water heater and an electric tankless water heater.

Let’s start with the former first….

Traditional water heaters have a 30 to 80 gallon tank that is used to heat and store water. The preheated water is then used for everyday functions such as showering, washing clothes and washing dishes.

Once the water in the tank is depleted the water heater will preheat more water and refill the tank.

While traditional water heaters are considered cheap and readily available, they also use a lot of power and don’t last very long.

They are also very big and can be a pain in the you know what to have repaired or replaced.

With an electric tankless water heater there is no preheating involved. Instead, the water is heated as it passes through the heater.

This is why it is often referred to as water on demand. With this type of heater there is no storage involved. The water is heated only when you need it.

While this type of unit can be very expensive, they do reduce power consumption and last several decades.

They are also small in size and relatively easy to repair or replace.

How Does an Electric Tankless Water Heater Work?

For the most part electric tankless water heaters use the same exact principles as traditional gas operated heaters.

The one big difference is instead of using a gas inlet for power they use a plug in socket. They also don’t have a tank and can therefore help you save a great deal of energy.

The most basic tankless water heater comes with a cold water line and a hookup for the electric.

Any extra components such as complicated designs or expensive piping will add to the price of the unit.

Generally speaking you will find specially designed coils that are either installed underneath the pipes or as part of the pipes.

These coils heat up the moment the power is switched on. However, the best tankless water heaters only heat up when the coils come in contact with water.

Otherwise you run the risk of burning out the piping elements.

Electric tankless water heaters are also very efficient. Typically you can expect a hot water rate between 2.5 and 7 gallons per minute.

Keep in mind the hot water rate can be limited by how much water is consumed in your home. If you have extremely high water demands even the most powerful coils won’t be enough.

The good news is replacement parts are very affordable and maintenance costs are very low. So even if you have to do some repairs it will still be worth it to have an electric tankless water heater in your home.

5 Reasons You Should Invest In an Electric Tankless Water Heater

Electric tankless water heaters have proven to be the best alternatives to traditional water heaters. Here are 5 reasons you should consider getting one for your home.

1) Electric Tankless Water Heaters Are Energy Efficient

Electric tankless water heaters only consume power when they need to. That means the system doesn’t do anything until you turn on the tap.

Because of this it is said that you can save up to 60% on energy costs. And being that most models have a close to 100% efficiency rate you can expect to save quite a bit of money on your monthly heating expenses.

2) Tankless Heaters Supply an Endless Flow of Hot Water

Have you ever worried that all the hot water will be gone by the time it’s your turn to take a shower?

This is a very common concern with traditional gas water heaters.

With an electric tankless water heater you will never have to worry about hot water running out. That’s because with this type of water heater you will have access to an endless supply of hot water whenever you need it.

Because remember this water heater is tankless and the water isn’t heated up until you need it.

3) They Are Eco-Friendly

If protecting the environment is important to you then you will love having an electric tankless water heater in your home.

As previously stated, this type of unit only uses energy when hot water is needed. Because of this less electricity is used and there is less damage done to the environment.

Additionally, some of the newer more modern models have been built using recyclable materials.

That means even when you are no longer able to use the unit the materials can still be used on something else.

4) Tankless Heaters Save Space

Being that these systems are tankless you don’t have to worry about a big tank taking up a ton of space in your home.

They are compact in size and can be installed in just about any spare space.

5) They Are Easy To Install

Electric tankless water heaters are without a doubt the easiest to install.  If you have some basic plumbing and electrical knowledge you may be able to install it yourself. Otherwise, you can always call a plumber.

5 Things You Should Be Aware Before Investing In an Electric Tankless Water Heater

As with all things there is a good and bad side to investing in an electric tankless water heater. With that being said, here are a few drawbacks worth bringing to your attention.

1) They Are Expensive To Install

Most homes aren’t equipped to handle the additional electrical load that comes from using this type of water heater.

As a result you will need to have your homes electrical system upgraded which in some cases can cost you upwards of $5000.

2) They Aren’t Ideal For People Who Live Alone

If you live alone you won’t save as much money with this type of water heater.

As a matter of fact, you may see your energy bill go up depending on how much water you use on tasks such as washing dishes and clothes.

3) Regular Descaling Is Required

These types of water heaters must be descaled by a professional on a regular basis.

And while these devices have become more popular in recent years, it can still be somewhat difficult to find a technician who knows what they are doing.

4) Tankless Water Heaters are Not as Effective In Cold Temperatures

At the moment electric tankless water heaters aren’t very effective in very cold temperatures.

It will usually take the device a ton of effort just to raise the temperature to the minimum required for hot water.

If you live in a cold climate region you may need to have more electric power installed.

5) Easily Ruined By Hard Water

If you have hard water it is extremely important you use a hard water softener. Otherwise you may find yourself having to replace your water heater sooner rather than later.

5 Questions To Ask When Choosing The Best Electric Tankless Water Heater

1) How Much Hot Water Do You Use In Your Home?

One of the most important things to consider when buying an electric tankless water heater is the efficiency and volume of water that will be flowing through the water heater on a regular basis.

How often will you use hot water on a daily basis in your home? How often will you use the shower or run the dishwasher?

Keep in mind this type of water heater can only let out so much hot water at a time. If the showers and dishwashers in your home take up too much hot water you will need to make sure you get a water heater that has the capacity to heat more water per minute.

2) What Size Water Heater Do You Need?

Since there is no tank when it comes to size the focus should be on the flow rate. This is what will help you determine the size and power of a tankless water heater.

The only way to calculate the flow rate, which is measured in Gallons Per Minute (GPM), is to know the BTU or British Thermal Unit.

The higher the BTU the better flow rate you will have.

The average tankless water heater will have a flow rate of 5.7 gallons per minute and will require 190,000 BTU’s.

There are of course smaller units that only deliver 1.2 gallons of water per minute. The smaller devices will only be effective for single outlet situations.

If you have a family and will be using multiple bathrooms at the same time opt for the higher flow rate.

3) What Is The Energy Efficiency Rating?

It’s no secret that electric tankless water heaters can consume a lot of power. If you plan on using the system to heat water for your whole house, make it a point to invest in a model that has a high energy efficiency rating.

Generally speaking the ratings will range from 78%-87%. A higher efficient rating means the unit is able to convert energy into heat at a much faster rate.

4) Where Will You Install The Water Heater?

The great thing about tankless units is their size. They are so small and compact that they can be installed just about anywhere.

From under the sink, to a small closet, to the storage room in the hallway, they can literally fit in any available space.

However, just because you can install it anywhere doesn’t mean you should. When considering a location there are a few important things you want to keep in mind that will ensure safe operation and easy accessibility.

First and foremost understand that most tankless water heaters will need to be installed indoors. If you want to install it outdoors you will need to invest in a suitable enclosure to protect the unit from outside elements such as sunlight, rain, insects and debris.

When choosing a location opt for an area that is close to both application fixtures and the main electrical panel.

If the unit is installed too far away from the electrical panel you will need a lot of extra wire to connect the water heater.

The time it takes for the hot water to go from the water heater to the water tap will depend on how close the water heater is to the hot water applications.

Generally speaking the process is extremely fast. The closer you install the unit to the hot water applications, the faster the hot water will make its way into your home.

One last thing you want to consider is ease of accessibility. There will come a time when you will need to service the unit. You should therefore make sure it is installed in a location that is easy to get to.

Please note ground temperatures can have a huge affect on how an electric tankless water heater performs. If you live in a region that is known for its cold weather, or you plan on installing the heater in a basement, make sure you get a unit with a high water flow rate.

This is because when the heater is installed in a cold location it will be forced to raise its temperatures well above ground temperatures just to reach the desired temperature for hot water.

Avoid installing the unit in a location that is subject to freezing temperatures. If water freezes inside the water heater it can cause serious damage that more than likely will not be covered by the warranty.

You should also avoid installing the unit near underwater pipes, next to combustible materials, above electrical boxes and any places where there is an excess of moisture, humidity and dust.

5) What Smart Functions Does The Unit Offer?

Look for a device that has smart functions designed to protect you and your family. For example, one smart function to look for is an automatic shut off if the unit overheats.

An oxygen depletion sensor is also a great smart function.

You should check for any smart functions that you feel are important.

Frequently Asked Questions

Before we close this buying guide out we wanted to quickly address some of the most commonly asked questions about electric tankless water heaters.

1) Can You Install a Tankless Water Heater Outdoors?

While you can install a tankless water heater outdoors, it is not recommended that you do so. This is because the elements of the system must always be protected from things such as freezing rain and hot sun.

If you do decide to install your unit outdoors, make sure you do so with a lot care.

2) Is Venting Required For This Type of Water Heater?

No. Venting is not needed for this type of water heater. Generally speaking venting is only required when using gas as its fuel type.

3) How Much Money Can You Save With a Tankless Water Heater?

While we can’t give you an exact amount of money that you will save by using this type of water heater, we can say that you can expect to save up to 50% on your energy costs.

4) How Do You Descale a Tankless Water Heater?

When it comes to descaling the process will vary depending on how soft your water is and what type of water heater you are using.

However, for the most part here are the 6 steps you will need to follow to descale your electric tankless water heater.

Step 1

Start by disconnecting the power source. You should also make sure all service valves and caps are closed.

Step 2

Fill a bucket with a gallon of water and pour in a quart of Flow aide.

Step 3

Grab a hose pump and put one end in the bucket and connect the other end to the cold valve on your water heater.

Step 4

Grab a second hose pump and place one end in the bucket and connect the other end to the hot valve on your water heater.

Step 5

Put the pump in ground receptacles and let it run for 45 minutes.

Step 6

The final step is the flush the water heater. This should take no more than 5 minutes. Once complete you can reassemble everything and start back using the water heater as normal.

Electric tankless water heaters: the final word

And there you have it. A complete buying guide that breaks down everything you need to know about electric tankless water heaters, as well as a selection of our 5 favorite tankless heaters from EcoSmart, Stiebel, Bosch, Rheem, and Stiogreen.

Before investing in one be sure you understand the pros and cons in doing so. Hopefully after you read this guide you will be able to make a well informed decision on not only whether an electric tankless water heater is a good option for your home, but also on which tankless water heater will work best for your situation.

Since we’re already so far down the post, here’s a quick water heater comparison table again for you that you can refer to.

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