Best Electric Tankless Water Heater Reviews 2020

Having to find the best electric tankless water heater in 2020 for your home is a wise choice environmentally and economically. You are energy efficient and you are also putting a substantial amount of money in your wallet. Keep in mind, you can always go with the gas option too.

Going with a gas-powered has its own considerations like a required venting clearance space. If your home is not hooked to a natural gas feed where you live, the electrical choice becomes the only one. In rural areas and for cottages as an example, getting an electric tankless water heater will prove to be an excellent option.

You will notice electric tankless water heaters are cheaper than the gas-powered one. When using an electric tankless water heater, you may be at a disadvantage when a power failure occurs without a proper backup. But on the positive side, electric tankless water heaters can be the ideal transition from a conventional storage electric water heater. The savings in your wallet will still be felt especially if you acquire the best tankless electric water heaters available on the market.

In this buyer’s guide, we will focus entirely on the best electric tankless water heater, you can get for your home, your cottage or even your office.

Best Electric Tankless Water Heaters For Your Home or Office

If you are using the conventional storage-tank water heaters, this is a great time to make that change towards an electric tankless water heater. An electrical storage-tank water heater consumes much more energy while a tankless consumes much less because it is “on-demand”. This means it will only heat your water when required.

An electric tankless water heater is also a lower capacity than its gas-powered counterpart. However, lower capacity electric on-demand water heaters can be placed in your home near a kitchen sink or a bathroom sink aimed at delivering hot water specifically in those rooms. This is useful if the existing storage water heater is located away from and with some distance from those faucets. This type of installation is also called “point of use.”

A point-of-use model is the perfect electric tankless water heater to use at a cottage, where the hot water requirement is much lower than in your home.

Buying the best electric tankless water heater requires some considerations. As an example, the very first thing to do is determine your flow rate, followed by the groundwater temperature. These two key pieces of information will give you the right electrical tankless water heater to purchase.

Let’s have a further look and understand what we mean and what you need to do.

Factors When Buying The Perfect Electric Tankless Water Heater

When buying the perfect electric tankless water heater the very first thin to determine is the flow rate.

1. Determining The Water Flow Rate

A water flow rate is a number of gallons per minute of water coming out of your tap or faucets. The unit of measurement is called GPM. When assessing the GPM in your house, simply identify the steady flow of hot water in each room.

So, in order to determine the accurate GPM measurement that you will need; add the totals of GPMs for your major fixtures in one particular room. The objective here is to get the GPMs for the major fixtures/appliances that you expect to use at the same time.

As an example, if you are running hot water from your bathroom faucet, at a flow rate of 1.0GPM and then your shower head is producing a GPM flow rate of 1.5 GPM simultaneously, then your flow rate flowing through the water heater you will need to get will have to be at least 2.5 GPM flow rate.

Next, you need to determine the ground water temperature.

2. Identifying the Ground Water Temperature

Identifying the ground water temperature is your next step. This is the temperature of your incoming cold water. It is calculated by assessing the difference between your incoming ground water temperature and your desired output temperature.

Here is an example to simplify the calculation

Above, we determined your flow rate was at 2.5GPM. So, as an example, you live in Southern California where the average ground water temperature is from 65∞ to 70∞ + Fahrenheit. By using the coldest temperature in the area you live, (ex: 65∞F) you will subtract this from your desired output temperature. Most households in North America have their desired output temperature set between 100∞ to 115∞F. So if you take a median temperature output of 110∞F minus the 65∞F for your local area, we get a rising temperature of 45∞F.

In addition, you would expect your electric tankless water heater to produce a minimum temperature rise of 55∞F.

Maps detailing of water ground temperatures are available online. You can see one here.

Finally, once your temperature is found and your flow rate is determined, your final step is selecting the right unit for your house, office or cottage.

3. Selecting The Right Electric Tankless Water Heater

This is the easiest part and is done by looking at the unit’s characteristics and features. In the features or in the product description, you will see the details showing the two numbers you have on hand, the flow rate and the temperature rise.

Simply look at the details showing your flow rate and your temperature rise.

As an example, we found the flow rate was set at 2.5GPM, our temperature rise is 45∞F. Therefore, we would be looking at those details when looking at an electric tankless water heater.

Comparison Chart Of The Best Electric Tankless Water Heaters

Rheem RTEX 13 Electric Tankless Water HeaterOne year warranty on parts

Ten year warranty on heat exchanger

Designed for point of use application

Professional installation required

ECO 27 Eco Smart Electric Tankless Water HeaterLifetime warranty on parts

Can handle more than one appliance at a time

99.8% energy rating

Professional installation required

Tempra 24 Plus by Stiebel Eltron Electric TanklessThree year warranty

Self-modulating technology for perfect water temperature

Features advanced microprocessor technology


Is Electric Better Than Gas?

This is always one of the first questions you will ask yourself when the time of buying a tankless water heater has come. There are several factors you can consider. Primarily, you will need to take these into account.

  • Electric Tankless Water Heaters Are More Affordable;
  • Electric Tankless Water Heaters Have a Higher Energy Factor (EF) Rating than Gas unit;
  • Electric Tankless Water Heaters Are Cleaner than the Gas-Powered Tankless Water Heater;
  • Electric Tankless Water Heaters Requires No Complicated Pipe Hook Ups
  • Electric Tankless Water Heaters Don’t Need Ventilation Clearance Space;
  • Electric Tankless Water Heaters Have No Combustion – So Less Maintenance;
  • Electric Tankless Water Heaters Can Be Compatible With Solar Powered Homes.

Maintenance and Care of an Electric Tankless Water Heater

As mentioned above, the maintenance of an electric tankless water heater is simpler in nature than a gas-powered tankless water heater. The main part that would require replacing over time is the heating element. Replacing a heating element in an electric tankless water heater is relatively simple.

Replacing The Heating Element Of An Electric Tankless Water Heater

First, you should always refer to the user manual or instruction guide to locate the heater element. Once done, apply all the safety precautions when dealing with electricity, which means shutting off the power to the electric tankless water heater. In addition, to avoid any mess, shut off the water supply to the tankless water heater. An isolation valve to a nearby pipe or hose will do the trick.

Second, drain the remaining hot water from your hot water tap at the sink by opening the hot water faucet. Next, remove the screws securing the underside of the water heater. The underside holds the heating chamber plate. Take the plate out and let the water come out. Once completed, replace the plate.

Your next step, disconnect the wires leading to the heating unit. Those wires may be held by screws in some units. Get a rag and wrap the heating element to avoid again more water to drip and create a mess. With a crescent wrench dismantle the heating element in the unit and remove it. When replacing a heating element, ensure you have the exact same type of heating element that was previously in the unit. Install the new heating element and ensure the O-ring is set properly.

Finally turn the water back on and turn the power back on. Give it a test and verify for any potential leaks, drips or cold water instead of hot water.

The next thing you should also watch for is hard water. Hard water is always the main culprit of electric tankless water heater breaking down, if they are not maintained.

Cleaning the Electric Tankless Water Heater

The reason we have hard water is mainly caused by the high rate of minerals in the water. These minerals are calcium and magnesium ions. When they sit in your water tanks, these minerals are sitting there and become hard buildup. This is the white buildup you see in kettles or faucet’s edge at times. These minerals will also sit within your electric tankless water heater when not in use and with time a buildup will occur.

When the buildup of calcium piles up, the heat exchanger gets clogged which will cause an overheat. This overheat provokes an error code and shuts down your water heater. This will result in no hot water and you will be required to remedy the problem by getting it cleaned. Preventive maintenance can go a long way and in this case, you will save a lot of money by doing this yourself.

Start by connecting a water softener system to your water source. If purchasing a new residence, inquire what the water is like in the house. By taking this first step, you reduce the intake of calcium and lime in your water that you are using throughout the house. It will have a positive effect on your electric tankless water heater and also throughout the piping system in your home.

Next, at the electric tankless water heater flush the water out of it every six months. Instead of getting it done, doing it yourself will save money on the maintenance of it or replacing it.

If you opt to clean your electric tankless water heater yourself, there is a good guide available here.

Other Considerations When Buying An Electric Tankless Water Heater

Like any changes in your home, transitioning from a conventional system to a more sophisticated one requires you to make sure you look at all the considerations of doing so. in the case of transitioning from a conventional storage hot water tank to an electric tankless water heater, you should always look at all the considerations it will entice. One other aspect you should look at is any electric tankless water heaters reviews storage water like the one we will provide you below on the best electric tankless water heaters in 2020.

First, let’s have a look at other considerations when buying an electric tankless water heater for your home.

The effect of living in a colder climate will be a consideration to look at especially when living in the northern U.S. (like in Wisconsin). We looked above at the ground water temperature and how important it was in the selection of the right unit. So in a colder climate, more usage of hot water will be required and have an effect on the units you get and where it should be placed.

On the side, if you are living in a climate that is warmer or even hot, your requirements for hot water changes. Less energy is consumed and less energy will be required to get hot water flowing. It will change the type of tankless water heater, you’d buy. As an example, a shower water temperature can be set at a temperature lower than you’d find in colder temperature. The length of time in the shower will also be less in many cases. This will have a direct effect on your GPM too.

People in warmer climates can probably get away with buying units with a lower gallons per minute (GPM) output or at least get to enjoy more reliable high-flow rates that people in colder climates. Thatís because a hot water heater thatís installed in a colder spot will have to work harder, which then lowers its overall output capacity.

The other consideration is the size of your home, the amount people living in the house and the efficiency of the appliances with regards to energy factor rate (EF). As an example, if you have an older washing machine, that is not energy efficient, then your requirements for hot water will change.

In addition, if you are cold washing your clothes, this is another consideration that will affect the demand for hot water in your home.

Next consideration will be the cost. You should always consider the installation cost of your electric tankless water heater, its location in the house and if a conversion or alteration is required in the plumbing or electrical wiring meeting all the building codes and finally its warranty. The good news about electric tankless water heaters is that they are much easier to install than the gas-powered unit.

Some electric tankless water heater manufacturers may require you to have it installed by a professional like a certified plumber. If you choose to do it yourself, you may void your warranty, if things go wrong. Consult your warranty policy with the instruction manual that comes with the water heater. A do-it-yourself may save you money now, but cost you more if you don’t follow the manufacturer’s policy.

Next, you need to consider that an electric tankless water heater requires being hardwired to the circuit breaker or the electrical panel. Therefore having an electrician do it may be easier, safer and cheaper in the long run. You should consider if the electrical circuit of your house can support the new water heater and not overload. An upgrade of your circuit breaker may be required.

Finally, because, it doesn’t require any ventilation clearing space, like a gas-powered unit, consider placing your electric tankless water heater in the best place possible without obstructing other access to utilities or other necessary products for your home.

Let’s move on to our electric tankless water heater review. Our review of the electric tankless water heater looks at many aspects of the electric tankless water heaters. For example, we look at the efficiency how it performs like its flow rate. We also looked at the warranty, how efficient it is in energy efficiency saving, how easy it is to install, its customer service and support and of course its cost.

We will eventually compile a list of our top 10 electric tankless water heaters, which I am sure you will find some great options in getting the best model.

Like any of our reviews, please feel free to comment and provide your own feedback if you own an electric tankless water heater. This will help our other readers and future users of a tankless water heater. In addition, it helps the growth of this website which in exchange benefits you the customer.

Electric Tankless Water Heater Reviews

To begin our electric tankless water review, we will start with the Rheem RTEX 13 Electric Tankless Water Heater, followed by the EcoSmart ECO 27 Electric Tankless Water Heater and conclude our top three with the Stiebel Eltron Tempra 24 Plus Electric Tankless Whole House Water Heater.

1.Rheem RTEX 13 Electric Tankless Water Heater Review

The Rheem RTE 13 Electric Tankless Water Heater for 4GPM is a perfect electric tankless water heater to be employed in a “point-of-use” location. It is a unit that is very compact so its installation will not intrude anywhere you would lack space.​

It is a very energy efficient tankless electric water heater. For small offices and smaller homes or even a condo, the Rheem RTE 13 Electric Tankless Water Heater has a LED temperature control display, which facilitates the setting of the water temperature and the element’s status.

The Rheem unit has a 1/2″ water connection brass heat exchanger application. Because it is only just over 7 inches in length and width, the tankless water heater from Rheem can be easily inserted in strategic location ensuring a continuous flow of hot water. This model features a flow rate of 4 gallons per minute (GPM), which is sufficient for a normal size home. It runs on a 13kw and 240v so easy to configure.

It is easy to install and it comes with a one-year warranty. As for the heat exchanger, the warranty is a generous ten years. Because it is an Energy Star certified product, your energy efficiency in your house will definitely improve.

The Rheem RTE 13 Electric Tankless Water Heater comes with a very detailed Instruction Manual, which will help you install the unit. Divided into two segments, the manual contains basic information and direction on how to install the Rheem 13 and adjusting the settings. In the second portion of the manual, you get more into the main features, how to operate the Rheem 13, the safety info and precautions and of course how to maintain your tankless water heater.

It is very explicit and Rheem is explaining very well how it works. They emphasize the fact that when you install the tankless water heater unit, you should always follow local building codes. The illustrations in the booklet are very simple to read and follow.

Below are the main features of the Rheem 13 Electric Tankless Water Heater:

  • 4GPM Flow Rate;
  • Ideal for Point-Of-Use Location;
  • 1/2 inches water connection heat exchanger;
  • LED Status Indicator;
  • compact and light;
  • Operates On 240 Volts/13KW;


The Rheem 13 Electric Tankless Water Heater provides 4GPM, which is an excellent flow rate. This will likely suffice for many smaller homes as a whole-house water heater. because of its generous flow rate, the Rheem 13, can deliver hot water consistently.

One great advantage of the Rheem 13 is its size and its easy installation. The unit is only over 7 inches in length and width so this tankless water heater can be installed anywhere out of view and in smaller rooms.

A very affordable unit, the Rheem 13 Electric Tankless Water Heater is the ideal water heater for the one wishing to transition from the conventional storage tank water heater. It becomes an excellent return on investment when you consider the money saved from your utilities and water consumption. It is one of the most affordable tankless water heater, which makes it a very popular choice.


With regards to the disadvantages of owning a Rheem 13 Electric Tankless Water Heater, we consolidated some of the comments and reviews researched on many consumer reports sites.

The Rheem 13 can be viewed as the “poor boy” of the electric tankless water heaters. One reason is because it was seen by a few customers and users as an electric tankless water heater, which had problems delivering the flow rate it says to deliver on a continual basis. Those cases were isolated and don’t represent a common flaw seen by their users.

Another small trend was noted with regards to the customer service. Some experienced isolated bureaucratic issues and their cases were passed from one rep to the next. This is unfortunate for them and doesn’t represent a common problem with Rheem at this time.

Some also questioned the durability of the Rheem 13. There were a few who just quit after a few weeks. Other were querying the casing of the tankless water heater, as they installed it. This can happen and we recommend all users to fill the warranty form, keep the box and receipts (proof of purchase).

Finally, some experienced a reduction in their hot water pressure once the Rheem 13 was installed. It may be due to the immediate “point-of-use location of the unit.

Endnotes on Rheem

We are proud to say the Rheem 13 Electric Tankless water Heater performed very well overall. This is a unit that is not expensive and fairly easy to install. Because of its smaller size, it can fit in areas where many of its immediate competition wouldn’t fit. The return on investment for the Rheem 13 is worth it. In the long run, the Rheem 13 Electric Tankless Water Heater will be able to provide enough hot water, especially if you live in a smaller house, a condo or a small office. If you are a larger family, you may consider another and bigger GPM rate.

2. EcoSmart ECO 27 Electric Tankless Water Heater Review

Next, we will look at the EcoSmart ECO 27 Electric Tankless Water Heater. This electric tankless water heater is manufactured by Smart Technology. The ECO 27 is a great electric tankless water heater if you are living in a colder climate. In fact, their tankless water heater can support and will heat ground water temperature as low as 37∞F. It is capable of heating up to 3 gallons per minute.

It is a great tankless water heater if you are a larger family, so everybody will have their share of hot water. The energy deployed to heat the water is well regulated through its self-modulating sensor. In order to maximize the setting’s accuracy, the hot water temperature is displayed on the digital readout in one-degree increments. The temperature ranges from 80∞F to 140∞F.

Strong and Durable

The ECO 27 model is one of many from the Smart Technology electric tankless water heaters. Their models range from ECO 8 to 36. The ECO 27 is one of their high-end tankless water heaters. This is based on amperage and capacity to heat the water flowing. With a 27Kw and 12A output, the ECO 27 electric tankless water heater is a durable and strong tankless water heater.

The unit measures 17″ X 17 inches, so it is not as compact as some electric tankless water heaters are. It will restrict your spaces where you want it placed. Due to its immense capacity, it can be placed outside the living areas and out of view.

We recommend strongly to have your circuit breaker examined by a certified electrician if your plan is to get the ECO 17. The reason behind this is the power drawn may cause some issues on your circuit breaker, which can be easily avoided, if seen by a professional.

Armed with a lifetime warranty, the ECO 27 electric tankless water heater is covered by the electronics, the exchanger, and the heater element. Keep in mind the warranty doesn’t cover heater cost, its labor or the incidental damages or negligence.

Below is a quick look at some of their main features.

ECO 27 Electric Tankless Water Features

  • capable to heat water temperature at 37∞F;
  • 27Kw and 12A power draw;
  • temperature can be set from 80∞F to 140∞F
  • ideal for larger homes and families
  • lifetime warranty on certain portion of the heater

Like any tankless water heaters, the ECO 27 has its pros and cons. below you will find the main pros and cons for this model of the ECO brand.


Because of its strength and capacity to heat up to 3 gallons per minutes, we definitely thought tit was one of their strong points. Coupled with the capacity to perform extremely well in colder climates and northern regions, the EcoSmart ECO 27 Electric Tankless Water Heater obtains strong points for performing where many would fail. Users were able to make use of the laundry while having showers or the dishwasher running simultaneously.

The EcoSmart ECO 27 Electric Tankless Water Heater is relatively well priced for the amount of heat delivers to your water. So it is very affordable considering it is one of the big tankless water heaters on the market.

The lifetime warranty is also a great advantage ECO Smart has put forward on all their ECO line products. The warranty can be transferred, so this is even a plus, plus.

The support offered online about the ECO 27 was also quite detailed. The references and the user manuals can easily be found which enhance their customer service.


The disadvantages of owning an EcoSmart ECO 27 Tankless Water Heater were heavily outnumbered by the positive comments and reviews, we researched. One of the major issues noted on the ECO 27 Tankless Water Heater was the installation wasn’t easy.

One other negative aspects of the ECO 27 Tankless Water Heater were the various conditions to qualify for the lifetime warranty. Just keep in mind, although there is a lifetime warranty there may be various criteria’s for not qualifying. In other words, if you read the fine print, you should be fine.

One comment to conclude our cons is to remind you that you need to make sure you have the proper circuit breaker capable of handling the ECO 27’s amperage draw. In addition, the installation will only be covered if installed by a certified technician, so there are additional cost involved.

Endnotes on Eco 27

Overall, the ECO 27 Electric Tankless Water Heater is a very reliable tankless water heater. It delivers up to 3 gallons a minute of hot water and in cold weather, the ECO 27 is the perfect link to hot water flowing at full capacity. Superb in cold weather climate, the ECO 27 is bar none one of the best electric tankless water heaters in 2020 amongst its competitors. It has the perfect draw for maintaining hot water when applications are used simultaneously. When we produced this electric tankless water review, we felt this product was above average in standards for quality and efficiency.

3. Stiebel Eltron Tempra 24 Plus Electric Tankless Whole House Water Heater Review

Considered to be the best electric tankless water heater by many users, the Stiebel Eltron Tempra 24 Plus Electric Tankless Whole-House Water Heater has been around a few years already in Europe. It is a tankless water heater operating on a 208/240v output. Its technology is above average in the tankless water heater industry, as expected from a German product.

Redesigned and upgraded for more efficiency and engineered with convenience in mind, the sleek Tempra Plus Electric Tankless Water Heater was equipped with an advanced flow control. The advanced flow control’s role is to automatically adjust water flow in order to reduce any lowered fluctuation of temperature and pressure.

The Tempra Plus 24 requires a minimum circuit breaker of 2 X 60A. The water heater draws 24 amps and delivers hot water at any given time while appliances or showers are running. Stiebel Eltron’s engineers wanted to keep it simple. This model was designed to have an easy access to the temperature selection and adjust it along the way.

Since it is not a large unit, the Tempra Plus is easy to install in any restricted space. A certified technician is not required, which will definitely save you extra cost.

One interesting fact about the Tempra Plus is that the unit doesn’t need to be seismic compliant. It is not part of the building codes like a hot storage water tank is required to abide by.

In saving 15 to 20% on your electricity bill from hot water usage, acquiring a Stiebel Eltron Tempra 24 Plus Electric Tankless Whole House Water Heater will become an excellent investment long term. As well, there are well covered by a 3-year warranty.

Now let’s have a look at their pros and cons.


The biggest advantage the Tempra Plus 24 Electric Tankless Water Heater can be proud of is the delivery of hot water for the whole house without any glitches. They are also great at providing hot water where colder climates exist and the ground water temperature hovers just above the 35∞F.

Their Advanced Flow Control is also a great and unique feature offered by the Tempra Plus 24. It will help your utility bill and the flow is not disrupted unnecessarily while in use.

The size is one positive aspect of the Stiebel Eltron Tempra Plus 24. Easy to install it will fit in restrained space and maximize your flooring space left vacant by your hot water tank. We liked the three-year warranty. Although it is not a lifetime one, with German quality products, you shouldn’t have too many issues to deal with your tankless water heater from Stiebel Eltron.


In some isolated cases, some users experienced issues with the thermal cut-off switch. It occurs when the heating element gets corroded and doesn’t turn off after the water flow is turned off. This malfunction results in the thermal cut off switch being triggered. Apparently, it is caused by the level of pH in your water. It is recommended to find out from your local city official how high or low is the level of pH and make a decision based on their response. If it is high above 7, then you could encounter the problem after a couple years.

End Notes on Tempra Plus 24

In summary, the Tempra Plus 24 from Stiebel Eltron is a very reliable and compact electric tankless water heater. It is capable of providing water for many consecutive showers. The device is quality-built and the settings can be easily adjusted in Fahrenheit or in Celsius. We definitely recommend it if you have a family and you are living in a larger house. Keep in mind, you should always verify the electric tolerance in your circuit breaker before buying the Tempra Plus 24.

Our Final Thoughts on the Best Electric Tankless Water Heaters

You have just read our detailed electric tankless water heater review. In this article, we reviewed three of the best tankless water heaters in 2020. This best electric tankless water heater review featured the Rheem RTE 13, the EcoSmart ECO 27 and finally the Tempra Plus 24. All three of these electric tankless water heaters are very reliable and are used in different homes sizes.

Remember, the electric tankless water heaters are very eco-friendly and can save you a tremendous amount of energy and money. In some cases having it installed by a certified technician is recommended. It prevents your warranty from getting void by doing it yourself. Others are easy to install and can be placed in compact areas of your house. Generally, they are not big in size. Having an “on-demand” water heater for your home will give you the satisfaction of an extra tool to conserve energy.

Feel free to comment below or to leave any feedback if you have purchased a tankless water heater.