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Best Electric Tankless Water Heater – Top 5 in 2021

When we think about the water heater, few options come into our minds- gas or electric water heater, storage tank or tankless water heater and so on. Among all the options we have, most of us will look for the best electric tankless water heater because of many reasons. The tankless electric water heater is sometimes referred to as a point of use water heater because these heaters do not preserve the hot water inside the tank. These heaters do not have any storage tank in it. Tankless water heaters are good for a small or medium house if you want to cover the whole house with one single hot water source. After reading the full article, you will be able to choose the best tankless electric water heater that is perfect for your utility. I have written another article on 110 volt electric tankless water heater. If you have a minimum level of consumption, you can also check our best list.

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Our Top Pick – Best electric tankless water heater

  1. Bosch Tronic 3000 T
  2. Ecosmart ECO 27
  3. Stiebel Eltron Tempra 29 Plus
  4. Titan SCR2 N-120
  5. Rheem RTE 13

Comparison table

ModelBosh 3000T-7GECO-27Stebel29+Titan N120Rheem 13
Flow rate@105F OutputNot Specified2.7GPM @37F Input3.1GPM @42F InputNot Specified1.53GPM @40F Input
Temperature65-145F80-140F86F - 140F65+F80-140F
Dimension (inch)17 x 17 x 14.517 x 17x 3.7516.5 x 4.6 x 14.510 x 2.5 x 74 x 9 x 13
weight (lbs)29.513.7510.47.954


Bosch Tronic 3000 T [ People’s choice]

Bosch is the renowned German brand. They produce high-quality home appliances. Bosch has three mini-tank water heater variants in terms of size- 2.5, 4 and 7 gallons. Out of these, I found that the 7-gallon version is the best considering value for the money. An important point to note is that these products are not purely tankless. But considering the size of the unit and the pattern it gives output water, these are very similar to a tankless water heater. Below are some of the key features of this unit:

Key features

  1. Electricity input: 14.4 KW, 120V, 12 A Max
  2. Output water temperature range: 65°F – 145°F
  3. Output water flow rate: Not specified
  4. Dimension: 10 x 10 x 16 inches
What we liked
  • This unit is fairly inexpensive. Out of all the products we researched, this is the only product that has a price tag of approximately $200.
  • Less energy consumption has made Bosch Tronic 3000 T different than any other tankless water heater in the market.
  • Unlike a storage-tank water heater, Tronic 3000T is highly energy efficient. This means there is not much energy loss, which makes this unit more inexpensive in the long run. The rated energy efficiency is 98%, but we believe you’ll still get at least 95%.
  • The design is compact. You can mount the unit vertically or horizontally as per your need. Therefore, it can save some space.
  • Time to time maintenance is less than other water heaters in the market. Also, the installation process is very simple.
What we did not like
  • If you are looking for hot water for the whole house, this item might be insufficient for you.
  • The flow rate is lower than others makes it better for the sink and kitchen only.


If your water consumption is not that much, you want a reliable tankless water heater from a reliable brand, then we must suggest you Bosch Tronic 3000T. Also, if you think that you need a boost to your existing water heater which is not giving you enough support, then this unit will be a good addition for you. The price point has made it unbeatable in the competition.

Ecosmart ECO 27 [Editor’s choice]

ECO 27 is probably among the most popular tankless water heater in the market. ECO 36  is another version similar to ECO 27. The only difference is the higher electricity input needed for the later version. For this reason, if you need a bit more water flow rate ( more output) you should go for the later one.

Key features

  1. Electricity input: 27KW, 240 volt, 112.5 Amp maximum
  2. Output water temperature range: 80°F – 140°F
  3. Output water flow rate: 2.7 GPM when the input water temperature is 37°F, the output water temperature is 105°F. The maximum flow rate is 6 GPM at a lower temperature.
  4. Dimension: 3.6 x 17 x 17 inches
  5. Activation flow rate: 0.3GPM
What we liked
  • One of the major advantages of Ecosmart is that it can give considerable output water of about 3 GPM even at a colder water input of 37°F.
  • The maximum flow rate of this unit is 6GPM, which is excellent.
  • Ecosmart 27 comes with a lifetime warranty. You do not need to worry about maintenance.
  • The rated energy efficiency of this unit is 99.8%. This machine will cut down your heating cost to 50% compared to the conventional tanked water heater.
  • It will give you precise control over the output water temperature. You can change the temperature within 1°F.
What we did not like
  • Installing process might seem unusual. Therefore, you might need support from professionals.
  • Warranty claims might be void if not installed as per the manufacturer’s instruction


Even though with some negative comments from the users, Ecosmart ECO 27 is one of the widely used tankless water heaters in the market. Considering everything, this one can be the best electric tankless water heater.

Stiebel Eltron Tempra 29 Plus [Best control over temperature]

Stiebel Eltron is the pioneer brand in the field of the heater and thermal equipment. The German company produces a good range of tankless water heater which are among the top three in the market. We have researched a few best-selling models and picked the perfect one on our list, which is Stiebel Eltron Tempra 29 Plus model.

Key features

  1. Electricity input: 28.8 W, 240 Volt, 120 Aam maximum
  2. Output water temperature range: 86°F – 140°
  3. Output water flow rate: 3.1GPM @42°F Input and 105°F Output Temperature
  4. Dimension: 5 x 4.6 x 14.5 inches
What we liked
  • The temperature control mechanism of this machine is exceptional. If the temperature is out of control, then the unit automatically reduces the flow slightly to keep the temperature unchanged.
  • The output hot water flow rate is higher than the other models we have compared.
  • It’ll consume 10-15% less energy than a conventional tank water heater.
  • It produces less noise during operation.
  • Water flow can be controlled automatically to save energy.
  • It comes with a cost-saving monitor which will show how much cost it saved which looks cool to us.
What we did not like
  • You have to spend a considerable amount of money to buy this unit.
  • Power consumption will be higher than other best-pick tankless water heaters we have reviewed here.


Stiebel Elton is specialized in heating equipment and it is a renowned European brand. This unit will give you output water which will be more precise in terms of temperature control than other renowned water heaters in the market. Therefore, if you have some extra money then we will recommend you to buy this unit.

Titan SCR2 N-120 [Best Value for money]

Titan N 120 has very good customers’ ratings in different marketplaces. Although this unit is not as popular as our previously reviewed models, after we researched considerably, we can say that it can certainly create value for you if it suits your needs.

Key features

  1. Electricity input: 220V, 54 Amp maximum
  2. Output water temperature range: 65 + degree F
  3. Output water flow rate: Not specified
  4. Dimension: 8 x 9.6 x 12 inches
What we liked
  • The price of the product is very reasonable.
  • The manufacturer claim that the machine saves your energy consumption 60% compared to the traditional tanked water heater.
  • 10 years limited warranty period seems good to us.
  • We found users’ reviews stating that this unit will serve you uninterruptedly for long years.
What we did not like
  • This machine is recommended to use for the warmer climate because it runs better at climate temperatures above 65°F. Therefore, if you live in a cold region, this unit might not suitable for you.
  • This is a good option for a medium-sized home only. Not recommended for bigger size home.
  • We found some warranty issues from the review of some users.


If you live in a medium home, looking for a trustworthy tankless water heater with a moderate price, then we must recommend you to buy this model. Considering price and equivalent quality, we have pick this one in our list of best electric tankless water heater.

Rheem RTE 13 [Best for backup]

Rheem Manufacturing Company is nearly 100 years old American company specialized in heat and refrigeration equipment. RTE 13 is the most popular and highly rated tankless water heater of the company. This product is compatible with a single shower or kitchen sink uses. However, there are higher capacity models RTE 18 and RTE 27 which are appropriate for higher capacity usage.

Key features

  1. Electricity input: 13W, 240 Volt, 54 Amp maximum
  2. Output water temperature range: 80°F-140°F
  3. Output water flow rate: 1.53GPM @40°F Input and 105°F Output Temperature
  4. Dimension: 4 x 9 x 13 inches
  5. Activation flow rate: 0.3GPM
What we liked
  • The price of this unit is on the lower side of the products we have reviewed.
  • The unit is very compact. Therefore, it can be installed anywhere.
What we did not like
  • The water flow rate at the cold climate (37F) is about 1.53GPM, which is good enough for one single shower. If the inlet water temperature is increased, it can serve up to two showers. Therefore, it is more compatible with warm regions.
  • This unit is not good enough to supply water to the whole house.


If you do not have much water consumption or thinking of a backup water heater of a good brand in a low budget, then I recommend this unit.



Tankless water heater

When a water heater is installed directly with the waterline, having no water tank, then it is called a tankless water heater. Water is passed inside the heat exchanger of the heater, and heat the water on-demand basis.


  • Energy-efficient- does not need to heat a whole tank of water to start supplying hot water; therefore, no ‘standby loss’.
  • Less wait time- it can instantly supply hot water. Tank type heater usually needs substantial time to heat the whole tank water first.
  • Unlimited water supply- unlike a tank-type water heater, a tankless water heater can supply unlimited hot water.
  • Less space is required to set it up and install
  • Temperature control is much better


  • The initial cost can be up to 4 times higher compared to a tanked water heater.
  • Most of the tankless water heaters are not suitable for intermittent use because the sensor cannot detect the water flow instantly. So, there is always a 1-3 second delay.
  • Sometimes, a tankless water heater cannot supply hot water more than a pre-rated speed.


Is a gas powered tankless water heater better?

It depends on various factors. If your water consumption is more and you live in a big family, then a electric tankless water heater may not be suitable for you. Below are the benefits and disadvantages of a gas tankless water heater that will help you understand better.


  • High GPM: these kinds of water heater can supply with more flow rate ( 8GPM or more).
  • Because of the higher capacity of hot water flow, these are suitable for a large house or commercial water consumption.


  • Gas water heaters require more maintenance than an electric water heater.
  • Inspection by a professional technician is highly recommended for a gas run tankless water heater to make sure that the gas combustion is running perfectly and safely.
  • Exhaust gas venting is a problem.

Buying guide

Flow rate

This will indicate the capacity of a water heater. For example, for a shower, the average flow rate will be about 1.5GPM. Therefore, if you want coverage for only one shower, then you must see what is the minimum flow rate of the water heater. At a warmer water temperature, your tankless water heater might give you a better flow rate. But I recommend you to check the flow rate at a colder environment.

Temperature range

This is a very important feature of a water heater to know before you buy it. For example, you want the water to be very hot for your cooking purpose and your water heater can not supply water more than 105°F then you’ll be in trouble. Therefore, make sure about the maximum temperature that your heater can provide you before buying.

Temp control

Sometimes you might need to control the temperature of the water precisely. For example, you need to control the temperature change within 1 degree. Therefore, make sure that your water heater can serve you this before you buy it. Another important aspect is, for precision control, you must need to see the temperature in a digital display. Do not forget to check this as well.

Electric consumption and efficiency

If you do not have much consumption but still want a heavy machine, you must have to pay extra on your electricity bill. The reason is that water heaters with higher flow rates come with higher electricity consumption ( higher KW rating). Therefore, when you buy, check the KW rating as well. If you find a lower rating which can serve your minimum requirement, then it’ll be better for you if you want to save some money in electricity bills.

The place to be installed

Not all tankless water heater looks the same. Some are compact and slim, some look cubic. Therefore, when you buy one, you must keep in mind about the place you are going to install it and choose your machine accordingly.

Installation requirement

Smaller machines are generally easy to install. But there are some water heaters which need some special requirements such as, 240 V electricity, higher Amperage, special electrical cord, etc. Before you buy your heater, we recommend you check installation requirements carefully and choose your machine.

Incoming water pressure

There is an incoming water pressure limit for every tankless water heater up to which it can work. For example, if this limit for the machine you intend to buy is 160 psi, you need to check whether it is below the water pressure of the line you are going to connect it. You need to add a pressure control valve if you find the water pressure of your water line is more than the limit of the machine.


You have to keep in mind that most of the renowned tankless water heater will give you at least 6 years of warranty. But check the terms and conditions to be eligible for warranty claim. For example, you might need to install the machine by the company employed technicians as a term of the warranty. Therefore, you need to know there beforehand.

Final Words

We have given a lot of effort to shortlist the best of the best electric tankless water heater. After finding the list, we have done extensive research on each model to find the suitability for the users. There is no doubt that each of the models we have reviewed is good to go. But users have different kinds of needs in terms of their utility pattern. Therefore, we tried to give an extensive and comprehensive idea so that readers do no mistakes while finding a suitable product. We expect that you leave a comment after reading our full article.


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