We all know the importance of a hot shower on a cold winter night, especially after coming home following an exhausting day at the office. But wait, once you get home, you have to wait another hour or so before the water is hot enough for you to really reap all the benefits of a cleansing hot shower because you own a water heater with a tank and it takes time to fill the tank up and then get the water temperature to rise.

Well, we have the perfect solution to your problem. The recent developments in the sanitary industry have made it possible to get instant hot water.

Yes, we are talking about the best electric tankless water heaters which you can install for your bathroom and have virtually no waiting time before getting hot water out of the faucet. These electric tankless water heaters are not only convenient to use but they also save a lot of money on energy expenditures, making them one of the best choices for your homes all around the globe. So let us get started and check out these electric tankless water heater reviews.

Electric Tankless Water Heater Reviews:

1. EcoSmart Eco 27 Electric Tankless Water Heater

EcoSmart ECO 27

When you talk about the best electric tankless water heater it is tough to look past this one in terms of performance and affordability. This water heater from EcoSmart gives you exceptional performance at an unbeatable price and works like magic for most small homes. The steel and copper heating elements of this device warm up your water rapidly while remaining rust-free for longer periods of time. The temperature control is exceptional with one-degree increments for greater efficiency and control. The compact design, almost as big as a laptop, is ideal for households where space may be an issue. The latest self-modulating technology adjusts the energy expenditure according to the load allowing you to save on water heating costs by up to 50% and overall energy costs by about 30% compared to traditional models.

The Eco 27 comes with a lifetime warranty when installed by professionals that show the confidence that EcoSmart has in its product. Keep in mind this warranty does not apply if you install it yourself. It works between 2.7-6.5 GPM which means that it can handle most temperatures but if you are a big family that lives in a cold area throughout the year you may want to buy an even more powerful model.

Some of its specifications are:

  • Weight of 14.7 lbs
  • The voltage of 240V with kW value of 27
  • Product dimensions of 17” x 17” x 3.625”
  • Digital temperature control
  • Latest self-modulating technology to conserve energy
  • Lifetime warranty when professionally installed
  • Durable steel and copper components


  • Self-modulating technology adjusts power usage according to requirements to give you a steady output
  • Lifetime warranty when assembled by professionals
  • Saves up to 50% on water heating costs


  • Flow rate lower than some of the pricier models in the market

2. Stiebel Tempra 12 Trend

Stiebel Tempra 12 Trend

The Stiebel company has been one of the pioneers and the most trusted companies when it comes to producing the best tankless water heaters with tons of experience. The Tempra 12 Trend is no different when it comes to providing absolute quality to their customers. It is one of the best investments you can make for your homes. The Tempra 12 Trend is a real money-saver since it is super efficient in its energy consumption. They claim this model to be 99% energy efficient and direct cost efficiency of 15-20% in comparison to the tank water heater modalities.

The installation process is very quick and convenient. If you live in a small place where space can be an issue, you need not worry since this model is just as big as a briefcase and fits anywhere with ease.

Some of its specifications are:

  • It is a residential product with an amperage of 50 amps
  • It has a gallons-per-minute of 2.34 GPM at 35 degrees and drops down to 1.26 GPM at 65 degrees
  • It is suitable for a bathroom with high flow in warm climates or a bathroom with low flow in cold climates
  • It has a 7-year heat exchanger warranty
  • It is fully adjustable with a backlit LCD display
  • It has a maximum temperature of 140-degree Fahrenheit and a minimum of 68 degrees


  • Super energy efficient, save 15-20% more money than tank water heaters
  • Fully adjustable with a backlit LCD for easy management


  • Good for 1 bathroom at maximum
  • Flow rates drop quite a bit in cold climates

3. Rheem RTEX-18 Residential Tankless Water Heater (Dual Heating Chambers)

Rheem RTEX 18

This lightweight electric water heater from Rheem gives you all the best features you need for your house at a reasonable price. It has a decent flow rate going up to 4.4 GPM enough for all your household needs. While lower quality tankless water heaters have a problem in maintaining an acceptable temperature through the operation but this model from Rheem does a good job at that due to the self-modulation technology. The two copper immersion heating elements work impressively to give you reliability and quick heating.

Perhaps the most desirable feature of this particular model is the ease of assembly. It requires the standard ¾ inch NPT water connection and any DIYer with a bit of experience can assemble it. It comes with an efficient LED display that allows you to easily change the heating temperature and a 5-year warranty.

Some of its features are

  • Weight of 8.5 lbs
  • Dimensions of 4 ½ x 15 ½ x 18 ½ inches
  • Can provide a decent flow rate range from 2.1-4.4 GPM
  • Simple installation due to the ¾ inch NPT water connection
  • The latest self-modulating technology saves power by shutting off when you do not need warm water
  • LED display with external temperature control ranging from 80 to 140 degrees
  • The voltage of 240V with 18 kW power with the recommended breaker size of (2 x 40)A


  • It is easy to assemble making it desirable for DIYers or those who want to save on installation fees
  • Durable heating elements and simple maintenance will save you money in the long run


  • Does not work as well with multiple showers in bigger houses

4. Rheem RTEX-13 Electric Water Heater

Rheem RTEX 13

The Rheem RTEX-13 is one of the best electric tankless water heaters available right now. It provides amazing energy efficiency and cost management. It has a small design which makes it ideal to be installed anywhere under the sinks or cabinets. This model is designed for point-of-use utilization where it is best if used to heat up a specific bathroom. It has very efficient temperature control mechanisms with a one-degree increment control from 80 to 140 degrees Fahrenheit on a backlit easy-to-read display and convertible between celsius and Fahrenheit for your convenience.

This model is designed for convenience where they promise easy installation, easy maintenance, and long durability with this device. It comes with a 5-year heat exchanger warranty and a 1-year parts warranty so you can rest assured that this is a product of quality.

Some of its features are:

  • Small design, easily fittable under any sink and cabinet
  • Energy-efficient saves money on electricity
  • Easy temperature control with one-degree increments available and an easy-to-read display
  • Temperatures available in both Celsius and Fahrenheit
  • Easy and quick installation and maintenance
  • Dimensions of 12×8.25×3.625
  • ½ inch NPT adapter included water connection


  • 5-year heat exchanger warranty
  • 1-year parts warranty
  • Energy-efficient; saves energy and cash
  • Small design best for one bathroom
  • Easily adjustable temperature control with one-degree increments between 80-140 degrees Fahrenheit, backlit display


  • Point-of-use model, only suitable for one bathroom
  • Flow rates drop at cold climates

5. EcoStar ECO 11 (Patented Self Modulating Technology)

EcoStar ECO 11

Not every house needs to spend too much money on an electric water heater. There are compact options available in the market to save you more than a few bucks. And a great example is the Eco 11 from EcoStar. It has all the energy-saving aspects you expect from EcoStar with a 0.98 energy rating and weighs just above 6 lbs. In your small flats, you need a lightweight compact water heater that can do its job without a fuss and this product can easily handle two sinks and a shower with a maximum of 3.1 GPM.

It has the standard lifetime warranty from EcoStar provided you get it installed by professionals so that DIYers do not do any damage on installation. The heating components are made of steel and copper to ensure durability and on-demand water heating. The temperature range from 80-140 degrees Fahrenheit allows it to be greatly customizable while the self-modulating technology saves water heating costs by up to 60%. This water heater will recover its cost in no time.

Some of its features are:

  • Weight of 6.5 lbs
  • Dimensions of 3.75 x 8 x 11.5 inches
  • A voltage of 220V with Wattage of 13 kA
  • Temperature range of standard 80-140 degree Fahrenheit common to other EcoStar models
  • Can give 1.3-3.1 GPM with optimal performance at 67° F and above
  • Energy factor of 0.98
  • Digital Temperature Control with advanced self-modulating technology
  • Lifetime warranty when installed professionally


  • Great performance for small and medium homes at an exceptional price
  • Takes up little space
  • Components are durable from a respected company


  • Lifetime warranty not valid if you install it yourself

6. Bosch Electric Mini-Tank Water Heater Tronic 3000


While this product is technically not tankless, but for all practical purposes, its small but spacious mini-tank behaves just like a tankless water heater and can fit right under a sink, and can also be used as a tankless water heater in RV’s. The Bosch Tronic 3000 is the ideal accomplice to your distantly located tankless water heater. It also does a great job of being the lone water heater for up to two sinks or showers or as a buffer for your existing water heater. It comes in both four or seven gallons so you can choose as per your requirements. The temperature range is from 65-145 degrees so that it can cater to a variety of external conditions.

Another luxury with this water heater is the ease of assembly and attachment as it can fit anywhere you want and the elegant design looks at home in a variety of settings. It runs on the standard 120V output making it easy for you to find a port for it. All in all, it is one of the top-rated electric water heaters on Amazon and it is easy to see why.

To sum up its features:

  • Weight of 29.5 lbs
  • Dimensions of 10 x 10 x 16 inches
  • The capacity of 7 Gallons
  • Voltage requirement of 120V at 12A
  • Temperature range of 65-145 °F
  • Easy to assemble with ¾ inch NPT
  • Magnesium anode rod heating element gives swift reliable hitting
  • Six-year warranty on the heater and one year warranty on the parts


  • Numerous mounting options and easy to assemble making the buying decision easier
  • Swift action so you do not have to wait for hot water at the sink or shower
  • Affordable price


  • Not suitable as a whole house water heater

7. Camplux ME40 Mini Tank Electric Water Heater

Camplux ME40

Sometimes you need hot water on the go for several necessary tasks like bathing your pet horses or dogs, or an outdoor shower during a camping trip. This is where the Camplux ME40 becomes valuable. It sets up in minutes with an easy procedure allowing you instant heating access to hot water up to 140 degrees Fahrenheit. It is the only product of its type that is CSA approved and has a lot to offer at an exceptional price.

The compatibility with pressures as low as 3 psi makes it incredibly convenient in your mountain cabins and camps on the go. It can provide 1.32 GPM which can be used for a conservative shower or any other application. The controls are easy with one knob to vary its heating function. Perhaps the biggest reason it is ideal for the outdoors is that it can easily be powered by two D-size batteries when you do not have a connection nearby.

Some other features are:

  • Weight of 21.2 lbs
  • Dimensions of 23.1 x 13.25 x 12.3 inches
  • Support for 2D cell lithium batteries so that it works without a plug
  • The wattage of 10kW and Voltage of 3V
  • Temperature range of 46.4℉ to 114.8℉
  • Can work at pressure as low as 3 psi
  • Instant hot water with 4 Gallon Capacity
  • One year warranty


  • Numerous installation options for your convenience
  • Can work with the pressure as little as 3 psi which is the best in the market
  • Can work without a plug with four Lithium batteries


  • The one year warranty is insufficient

Electric Tankless Water Heaters: Buying Guide

Buying a tankless electric water heater is a great way to save up on your electric bills while ensuring a constant supply of hot water for your house. However, with so many types of water heaters in the market, it can become tough to choose the right product for your needs. Let us look at some of the factors you need to keep in mind when buying an electric water heater.

Types of Electric Tankless Water Heaters:

Two main types of electric tankless water heaters are available right now. These are condensing and non-condensing.

Condensing vs Non Condensing Tankless Water-Heater

Non-Condensing Tankless Water Heaters:
The non-condensing type is the older one and uses a heat-exchange method for heating up the water. It uses stainless steel pipes for its exhaust. Since it is an older modality, it is simpler than its counterpart, meaning the technicalities are a lot simpler. They have a lower installation cost and have fewer chances to malfunction.

Condensing Tankless Water Heaters:

The condensing type is the more recent modality where it uses PVC pipes which are cheaper than the stainless steel ones. Yet, the overall cost of the whole system is more expensive. Since they use a high-temperature heat exhaust, they are more energy-efficient.

A more consumer-related approach divides the electric tankless water heaters into fully-on, fully-off, and modulated types.

The fully-on, fully-off type as the name suggests, will either heat up the water completely or not heat it at all. This type has the disadvantage of sometimes having a risk of overheating and posing a threat of damaging your pipes and wiring.

The modulated type is the more recent modality where it works with a control system that allows it to monitor and adjust the heating and flow of water through it. This type is a lot safer than the former since it has sensors that detect and adjust the system settings according to the needs.

Gallons Per Minute (GPM)

Gallons per minute is the amount of water one electric tankless water heater can heat by a set factor of temperature. They usually offer a 25-50 degree temperature rise. So, an electric tankless water heater with a GPM of 4 means that it has the capacity to raise the temperature of 4 gallons of water by ‘x’ degrees every minute. A typical shower uses around 1.5-2.5 GPM. So, this information is critical to get a heater tailored to your needs.

Heating Time

Heating time is the amount of time an electric tankless water heater takes to increase the temperature of water to the set temperature. Most electric tankless water heaters will heat up the water instantaneously. Of course, the factor of when that hot water actually reaches the faucet is to be taken into account. This heating time also depends on the inlet temperature of the water. Naturally, a higher inlet temperature means the heater can heat up the water quickly and a lower inlet temperature means it will take longer. This depends on what part of the country you are living in. It can also depend on the diameter of the pipes since wider pipes contain more water and lesser pressure, more water needs to be heated up which then waits for enough pressure to actually reach the faucet.

Local Climate

You can get the best electric tankless water heater out there, and yet it might not be the best for you. The local climate plays an integral role in determining the performance of an electric tankless water heater. As discussed earlier, the inlet temperature is a major factor in determining the heating time of your machine and the GPM it will deliver. If you live in a hot climate where the groundwater temperature remains high or closer to your demands, you can get very good gallons per minute from your heater. Contrary to this, if you live in an area where the groundwater temperatures are low and the difference between your desired temperature and the inlet temperature is big, you will need a more powerful electric tankless water heater to cater to your needs. It will produce lower gallons per minute rating and you will have to invest a little more to get your desired result.

Installation Cost

The installation costs can vary with your location depending upon your local plumbing rates. The installation cost of the electric tankless water heaters can be anywhere between $2500-4500$ on average. It can go as low as one grand or as high as six grand but again, that is a highly subjective matter. That being said, we would suggest that you still get a professional to install it for you and refrain from making it a do-it-yourself project since the companies will not offer you any warranty if you install them yourself.

The average hourly rate of a plumber is between $45-150. The installation process can usually take between two to three hours. The plumber will first take out your old system and then install the new one. There can be some miscellaneous expenses during the installation which can include water pipes, heat pipes, and the likes. All of these can add an additional $250-500 to the cost. You may need to pay for drywalls if any of the walls need opening, which can add an extra $200 to the bill. Electric tankless water heaters usually have a door built to them in order to have easier access to any maintenance and upgrades in the future. This can add to the cost of the door and a carpenter or a handyman. If you live in a cold area, the pipes may require insulation. This can add an extra cost to the project, not to mention that labor in these areas is also a little on the expensive side compared to other regions.


water heater maintenance tips

Electric tankless water heaters require maintenance as a necessity. Most of these can work for about twenty years but that is with regular maintenance. You must do maintenance every six months in order for the machine to work at its maximum. Especially, if your area has hard water or very cold water which needs the heater to be run at high values at all times, maintenance becomes key to a long-serving heater.

Hard water contains minerals such as Calcium and Magnesium. These can get deposited inside the pipes and heat exchangers. Once they build up inside the pipes, they will make the heater have to work harder to make the same amount of water hot. On top of that, it can significantly reduce the life of the heat exchanger system as well. Therefore, you must clean these pipes regularly to make sure nothing gets deposited inside them. Yearly cleaning of the lime is recommended to keep your water heater working optimally.


Since the electric tankless water heaters provide an endless supply of hot water, you do not need to worry about the capacity. These heaters work on flow rate, which means the number of gallons of water used at one particular time.

Let’s say we have 2 showers running at the same time. Considering that the average GPM of a shower is about 1.5, you will need an electric tankless water heater of 3 GPM (gallons per minute) and it will easily cover your usage.

Nowadays, we have tankless water heaters with GPM ranges that cover almost every house’s needs. Whether you are a family of 5 or a place with 15 people living in it, you can find an electric tankless water heater that can cater to your needs. So, basically what you need to figure out is how many gallons of water do you require at one particular time (you can call it peak timing) and then purchase a product that best fits your requirements.


Q: What are the pros and cons of tankless water heaters?

Tankless water heaters are some of the most innovative solutions for your hot water needs. There are obvious pros and cons to them so let us discuss them starting with the pros.


  • They can last several years with the high-end models working great for up to a decade due to their durable heating elements
  • They can provide hot water in a matter of seconds in comparison to their tank alternatives that first fill the water and then take time to heat it
  • They can save you on monthly expenses. It is said that if your home uses 41 gallons or less of hot water daily, tankless water heaters can be 20-30% more energy-saving than tank water heaters. The money saved in these monthly bills tends to pile up
  • They are lightweight and compact saving up on space which would be a blessing for people living in apartments or small homes
  • They only run when they are needed as the top models have self-modulating technology to ensure they only run when needed
  • They are available in both electric and gas models and are even available in portable models that run on batteries when you do not have a port available. This is in contrast to tank models that are not as versatile.


  • Despite several advanced models available nowadays tankless water heaters still have a limited GPM capacity which is lower than tank storage models. Some of the tank storage models can store 80 Gallons that can power several functions at once in a big house, unlike a tankless water heater.
  • They definitely have a higher upfront cost than tank storage models. This is, of course, made up for by their energy-saving characteristics but sometimes one is not ready to wait for that as these features may take years for you to recover your investment
  • Yearly maintenance may be required for lime deposits on the metallic heating elements so a water softener may also be needed to be paired with your tankless electric water heater

Q: How much water does a 20-minute shower use?

An average shower uses about 1.5-2.5 gallons per minute. Taking this value into consideration, a 20-minute shower will use somewhere between 30-50 gallons of water. A lot of this depends on what pressure and flow rate shower you have installed in your bathroom for a more precise estimate.

Q: What size tankless water heater do I need?

There are two main determinants of this decision. One is the total flow rate you need and the other is the temperature rise you desire.

To calculate the flow rate, you can add the GPM of all the appliances you may be used at once in your home. For example, a tub may use up to 4 GPM while a shower uses about 2.5 GPM. This sum would be the capacity you need. If you are a small family living in an apartment or a small house, you can sacrifice on the GPM to save you a few bucks.

The temperature rise is the number you get by subtracting the inlet temperature from the desired temperature. Inlet temperature may vary from area to area and so you may not need much temperature rise in warmer climate areas. If you know these two factors your decision will become all that much easier.

Q: Are electric tankless water heaters worth it?

This question is mostly asked by comparing electric tankless water heaters with gas tankless water heaters. There are no clear winners here but a few things to be considered. Gas Tankless heaters cost about twice as much as Electric Tankless Water heaters. However, they save you more than $100 in bills every year compared to electric heaters that save you from $40-50. This is because gas prices are less than those of electricity. Moreover, gas tankless water heaters can produce more hot water for you than electric water heaters but require greater and more frequent maintenance. Electric water heaters are much easier to install but their warranties are usually half of gas water heaters. So there are obvious advantages and drawbacks of both options and you should choose according to your individual needs.

Q: Can tankless water heaters run the whole house?

There are two types of electric tankless water heaters: The point-of-use type and the whole-house type. The point-of-use water heaters are installed for the purposes of augmentation of already installed water heaters rather than a replacement of one. These water heaters can heat only a specific bathroom since they have low flow rates and are specifically designed to heat up the water of one room.

The whole house water heater type is one with a lot higher GPM since they have to run multiple rooms at the same time. These models may be bigger in size and they are usually installed in a place that is a center point of multiple rooms, in order to heat up the water of all these rooms equally at the same time.

Q: Does an electric tankless water heater system always produce hot water on demand?

Electric tankless water heaters provide water on demand. As their name indicates, they do not have a tank capacity to hold hot water. So, they heat up water with their very efficient heat exchanger systems when you turn on the tap and they heat up the water in a matter of seconds. That being said, you do have to take into account the flow rates that the different models and companies have to offer because these tankless modalities have a gallons per minute flow rate system. They can only heat up a specific amount of water by a specific amount of degrees at a time, so you may need to consult a chart that explains the flow rates and supply-and-demand rules of these devices.

Over To You

At this juncture, you have enough insight into the best electric tankless water heaters in 2021 on the market. We have tried to cover all the best models available in the market that could cater to a variety of users in all kinds of settings. Be sure to do an ample amount of research and read tankless electric water heater reviews before buying an electric water heater because if you buy it right it could easily last you a decade providing constant hot water.

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