Best Electric Tankless Water Heater | Reviews & Buying Guide of 2020

Are you looking for an electric water heater ideal for everyday use in your home? We advise you to invest in the electric tankless water heater. It is the smallest in the electric heater genre as it does not require much space for installation. So it is suitable even for a small house. 

Difficult to make a choice for your new electric tankless Water Heater? We have written this special best electric tankless water Heater buying guide to help you, with the TOP 10 of the best sellers of the moment, we tests, reviews for our buying guide. We have done our best to help you choose the top classelectric tankless Water Heater for your home!

Unlike the tank water heater, its use is simpler and faster. Tankless water heater only heats when the water is drawn from the tap. While those with accumulation takes quite a long time to fill enough water in its cumulus, then heat it.

This instant water heater holds a high electrical power which allows you to produce the domestic hot water you need. In addition, it is a product that consumes less energy. Very practical for daily use, as well as during the cold seasons. This article is dedicated to guide you in the investment of your tankless water heater.

The electric water heater is a practical solution for the distribution of sanitary water also. The appliance has the capacity to supply hot water immediately, without limit and on-demand. There are many advantages also.

10 Best Electric Tankless Water Heaters


Stibel Eltron

  • Dimension: 63 x 16.63 x 14.5 inches
  • Voltage: 240 volts
  • Item Weight: 1 lbs
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Stibel Eltron Tempra Plus

  • Dimension: 52 x 16.54 x 4.61 inches
  • Voltage: 240 volts
  • Item Weight: 19 lbs
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Rheem RTEX-13

  • Dimension: 4 x 8 x 13 inches
  • Voltage: 240 volts
  • Item Weight: 4 lbs
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Rheem RTEX-18

  • Dimension: 4 x 15 x 19 inches
  • Voltage: 120 volts
  • Item Weight: 8.5 lbs
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Rheem RTEX-24

  • Dimension: 4 x 18 x 19 inches
  • Voltage: 240 volts
  • Item Weight: 8 lbs
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EcoSmart Eco 27

  • Dimension: 17 x 17 x 3.6 inches
  • Voltage: 240 volts
  • Item Weight: 11 lbs
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EcoSmart Eco 36

  • Dimension: 17 x 19 x 3.8 inches
  • Voltage: 240 volts
  • Item Weight: 35 lbs
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Titan SCR-2 N120

  • Dimension: 12 x 10 x 5 lbs
  • Voltage: 220 volts
  • Item Weight: 2 lbs
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Stibel Eltron DHC-E12

  • Dimension: 1 x 7.9 x 14.2 inches
  • Voltage: 240 volts
  • Item Weight: 94 lbs
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Stibel Electrol Tempra Plus

  • Dimension: 54 x 4.61 x 14.53 inches
  • Voltage: 220 volts
  • Item Weight: 37 lbs
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1. Stibel Eltron Tankless Water Heater

Stibel Eltron Tankless Water Heater


  • 15 KW
  • 240 volts
  • Digital Display
  • Advanced flow technology
  • Dimension 63 x 16.63 x 14.5 inches
  • 1 lb in weight

The Stibel Eltron has comes with 4.5 rating out of 5 and 6000 users excellent reviews which is the first tankless water heater in our round-up. This is one of the best water heater by Electric with advanced flow technology and digital display in a compact and simple design.

There is advanced flow technology to provide the maximum flow in a larger family with two or three bathrooms in silent operation. Its digital display will ensure the accurate temperature delivery to get perfect hot water.

You can set the output temperature through its pre-set button. As well as it has bought 7 years leakage warranty. Though it is a completely smart water heater, some users complained “it is very hard to set up and install by one person”.

With these features and facilities, this product is lightweight in a compact and sleek design which is a space saver and energy efficiency electric water heater. As a result, this Stiebel Eltron Tankless Water Heater is a great choice to provide the heated water in your home.


  • Sleek and Compact Unit Design
  • Lightweight
  • Space Saver
  • Energy Efficiency
  • Silent Operation
  • 7 Years Warranty


  • It is hard to set up this water heater by a man
  • Low GPM output

2. Stibel Eltron Tempra Plus Electric Tankless Water Heater

Stiebel Eltron Tempra Water Heater


  • 36 KW
  • 150 A
  • 240 Volts
  • 52” x 16.54” x 4.61”
  • 19 lbs in weight

If you are looking for an energy-efficient water heater, the Stiebel Eltron Tempra Plus is a solid solution for you.

There is a digital temperature control system to heat the water in uniform temperature. This water heater is 14.52 x 16.54 x 4.61 inches in size with a smart and simple design that’s very easy to set up everywhere.

Though it is capable to heat water on your demand, the Tempra plus does not work well in frigid temperatures. As well as this water heater is 15 – 20 percent energy efficiency than other electric water heaters.

Its whole body manufactured with eco-friendly durable materials. This product comes with 7 years leakage warranty and 3 years warranty on parts.


  • Digital Temperature control
  • Easy to install and setup
  • Energy efficiency
  • Space saver
  • Durable construction
  • Eco balanced body frame


  • Does not work well in cold/frigid temperature

3. Rheem RTEX-13 Tankless Water Heater

Rheem RTEX-13 Tankless Water Heater


  • 240 Volts
  • 54 A
  • 4 x 8 x 13 inches
  • 17 GPM flow
  • LED Display
  • Digital Temperature Display
  • External thermostatic control support
  • 4 lbs in weight

Rheem RTEX-13 is a another top pick tankless water heaters for a single couple and small household. There is a maximum flow of 3.17 GPM which is enough for your single bathroom.

This product is 4”x 8”x 13” inches in size with a simple design which is very easy to set up and replace in anytime. There is durable copper immersion two heating elements entire the body to assure the accurate temperature.

As well as It allows you to add external adjustable thermostatic control with LED Display where you can control your hot water temperature. Even, several users complained about its low flow which does not work for multiple showers.

The Rheem RTEX-13 is a great option for you which assures your daily hot water demands in a comfortable temperature.


  • Easy to install and replacement
  • 8% energy efficient
  • Durable copper construction
  • Adjustable digital thermostatic control


  • Low flow is very short
  • It doesn’t work well for multiple Showers

4. Rheem RTEX-18 Tankless Water Heater

Rheem RTEX-18 Tankless Water Heater


  • Advanced self-modulation technology
  • Digital temperature display
  • 4 GPM flow rate
  • External thermostatic control
  • LED Screen
  • Digital Temperature Display
  • 4 lbs in weight

If you are looking for a smart tankless water heater with multiple facilities, the Rheem RTEX-18 is one of the best choices for you. This is a water heater with digital features and the most self-modulation technology.

This product supports to add an external digital thermostatic control with an LED display that offers to set in 1-degree accuracy. There is most advanced self-modulation system to meet the power to get hot water on demand.

It is constructed with durable copper immersion with two heating elements that provide identical temperatures towards the water.

With these features and facilities, this water heater is smart and simple in design which is very easy to install. As well as this electric water heater is an easy replacement in a field serviceable.


  • Easy to Install
  • Durable copper Immersion
  • Field Serviceable
  • Digital temperature control in 1-degree accuracy
  • Easy to handle
  • 2 Heating elements


  • Low flow is very short
  • It doesn’t work well for multiple Showers

5. Rheem RTEX-24 Residential Tankless Water Heater

Rheem RTEX-18 Tankless Water Heater


  • Self-modulation technology
  • 3 heating elements
  • 9 GPM Flow Rate
  • Digital temperature display
  • External digital thermostatic control
  • Dimension 4 x 18 x 19 inches
  • Weight 8 lbs

This Rheem RTEX-24 Residential is another residential tankless water heater in our round-up from Rheem.

This water heater provides an opportunity to add an external digital thermostatic controller with LED Display which shows accurate temperature and allows to control temperature 1-degree accuracy.

There is an advanced self-modulation system to meet the perfect temperature and get comfortable heat water. Its whole body structure manufactured with copper immersion and the inner site made with three chambers which provides equivalent heat toward the water. 

With these facilities, this product is very simple and sleek in design, that’s very easy to set up in everywhere you want.

If you want to buy a smart Tankless Water heater with a high flow rate, the Rheem RTEX-24 is a great offer to you which will fulfill your demand for a long time.


  • Simple Installation
  • Easy replacement
  • High flow Rate
  • Durable copper immersion
  • LED screen


  • It can’t fulfill a larger house water demand

6. Ecosmart Eco 27 Tankless Water Heater

EcoSmart ECO 27 Electric Tankless Water Heater


  • 27 KW
  • 200 A
  • 240 Volts
  • Digital Temperature control
  • 3 GPM activation flow
  • Dimension 17 x 17 x 3.625 inches

When you want to buy a powerful water heater for a medium-sized household, the EcoSmart Eco is a great choice for you. This is the most powerful tankless water heater to handle on-demand water in even the coldest weather.

There is a high power heating system that capable to heat 6 GPM in the warm season and 3 GPM in the coldest climate for 37 degrees Celsius. 

For this facility, some people use this product as their sole water heater for cabins, lakes, and other vacation properties. Its similar modulating control can adjust power usage and pressure setting that provides hot water inconsistent temperature with a high flow rate.

Though this product has bought multiple facilities with a lifetime warranty, it comes with an affordable price. If you can buy EcoSmart Eco 27, it will assure your heat water demand in your home for a long time.


  • Simple installation and setup
  • Energy efficiency
  • Space saver
  • Durable construction
  • Easy to control the temperature
  • Lifetime warranty


  • Make hassle on warranty
  • It can’t supply enough GPM for larger households

7. EcoSmart Eco 36 Electric Tankless Water Heater

EcoSmart ECO 27 Electric Tankless Water Heater


  • 150 A
  • 240 Volts
  • 36 KW
  • Pipe fittings
  • Digital Output Temperature Display
  • Dimension 17 x 19 x 3.8 inches
  • Weight 35 lbs

Ecosmart Eco 36 is another electric water heater from EcoSmart with affordable price in our round-up. This is also another tankless water heater for a medium-sized house which capable to fulfill your hot water demand.

This EcoSmart has bought a digital output temperature display to show an accurate temperature. It is manufactured with a durable metal that lasts for a long time without face any hassle.

There is a powerful heating technology includes in this electric water heater that able to heat water 37 degrees Fahrenheit in cold weather and 67 degrees Fahrenheit in a warm climate. It can supply about 6.5 GPM as a maximum flow rate and 3.5 GPM as a minimum flow rate which is enough for medium or small-medium households.

The EcoSmart Eco 36 is the best option to buy to heat your water. It will ensure your hot water demand for a long time.


  • Compact and sleek Design
  • 8% energy efficiency
  • Digital Display
  • Space saver
  • Maximum flow rate


  • It works delay on flashing

8. Titan SCR2 N-120 Tankless Water Heater

Titan SCR2 N-120 Tankless Water Heater


  • 220 Volts
  • 54 A
  • Dimension 12 x 10 x 5 inches
  • Flow Rate- 4 GPM
  • 2 lbs in weight

If you are searching for a tankless water heater with a high flow rate, the Titan SCR-2 N-120 is one of the great solutions for you. This Electric water heater is very small in size with lightweight design. Though it is small in size, it is capable to supply 4.0 Gallon per minute with 20 degrees F as a maximum flow rate.

This product has manufactured with durable and long last metal bodies in a small design which is very easy to install and set up in a short place. It includes a push-button to set the temperature and there is an LCD screen to show the accurate temperature and low to the high-temperature graph.

The Titan SCR-2 has bought 10 Years warranty on water-carrying components which is a great opportunity for you.


  • Easy Installation
  • Easy to use
  • Lightweight
  • Compact size with High GPM
  • 10 Years Warranty
  • Cheaper than other tankless water heaters


  • High starting temperature

9. Stiebel Eltron DHC-E12 Tankless Water Heater

Stibel Eltron DHC 12


  • 12 KW
  • 240 volts
  • Weight 94 lbs
  • Dimension 1 x 7.9 x 14.2 inches

The Stiebel Eltron is another tankless water heater from Stiebel. It will a best choose at affordable prices. There are multiple facilities include in this product in a compact and smart design.

This Eltron DHC E-12 is capable to heat and supply the hot water on your demand in both warm and cold climates. It has come with a temperature adjustable knob to adjust the temperature between 86 degrees F to 125 Degree F so that you can get hot water at a comfortable temperature quickly. And its 99% energy efficiency ratings save more than 20% electric bill than another electric water heater.

Nevertheless, this Stibel Eltron Tankless Water heater has bought a 3-year warranty on parts for commercial and residential uses. With these features and facilities, this is a solid option to buy a water heater and get hot water on your demand.


  • It is easy to Install
  • Compact and attractive design
  • Self-modulating Technology adjust the electricity usage
  • Electronic Temperature control provides a constant output temperature
  • Easy to use


  • The plastic outer layer will make cracks
  • Doesn’t work well in a large home

10. Stiebel Eltron Tempra Plus Tankless Water Heater

Stiebel Eltron Tempra Water Heater


  • 220 volts
  • 29 KW
  • Weight 37 lbs
  • No venting required
  • Silent Operation
  • Dimension 54 x 4.61 x 14.53 inches

Stiebel Eltron Tempra Plus is the most powerful tankless water heater from Stiebel. It comes with high ratings and excellent reviews by its users.

This product is constructed in a sleek and simple design that offers a simple installation anywhere. As well as it provides an easy replacement opportunity for field service.

There is an adjusting with digital temperature display to adjust the temperature between 46-140 degrees F. Though its flow rate depends on the hot water temperature, it capable to supply up to 8.0 GPM (gallon per minute) as maximum flow rate and 4.0 GPM as minimum flow rate.

The interesting thing about this water heater saves 15-20% electric bill than other water heaters. Moreover, it has bought 7 years leakage warranty and 3 years warranty on parts.

If you want to buy an electric tankless water heater for your whole house or commercial places, the Stiebel Eltron 29 Tempra is a great option to buy at your affordable price.


  • Sleek and Lightweight Design
  • Advanced flow control
  • 15-20% electric bill saving system
  • Longtime warranty


  • It’s more expensive than other tankless water heaters

Buying Guide of Electric Tankless Water Heater

Intended to produce domestic hot water on demand, the best electric tankless water heater has many advantages to seduce. But is it really suited to your needs? Which power to choose? And what are its constraints, in terms of electrical connection? We tell you everything to choose well.

Tankless Electric Water Heater: Installation Configuration

To choose a tankless electric water heater, it is better to start by making sure that this domestic hot water production system is the one that suits you.

In the absence of a tank water heater, known as a tank, the tankless water heater does not store hot water, but supplies it as you use it thanks to an electric resistance that heats the water directly by contact.

With its very small footprint, the tankless water heater is perfectly suited to small spaces. In mini version, an instant sink water heater  can thus reach the size of a milk carton!

It is also ideal as a backup water heater for a room that is too far from the  main water heater . With it, you no longer have to wait to have hot water, available in unlimited quantities . 

With an affordable price and water that is only heated on demand, the tankless electric water heater is an economical solution. Other advantages: it is easy to install and requires no maintenance.

Be careful however, the instantaneous water heater is reserved for small dwellings and rather for the supply of a single water point because of its limited flow. The more you want high temperature water, the more you will see its flow decrease. 

In order for the water to be hotter, it must in fact remain in contact with the heating resistor for a longer time, which implies that the water passes slower and therefore a reduced flow rate.

There is therefore no point in hoping to meet the hot water needs of a large family. For the same reasons, the water should not be too cold in your region (in the mountains for example) because in this case the instantaneous water heater will not be able to heat it enough for it to reach a comfortable temperature. 

Finally, the instantaneous water heater must imperatively be installed near the water point, ideally between 20 cm and 3 m from the bathroom  or the kitchen  for example, so that the water does not cool in the pipes.

The Composition of the Tankless Electric Water Heater

  • In the form of a small box, the tankless electric water heater is composed of
  • A cold water inlet and a hot water outlet
  • A vacuum switch
  • A heating chamber in which the electrical resistance is located
  • A device for adjusting the water flow
  • A hydraulic safety valve
  • If the tankless electric water heater is intended to supply several water points, a T will be installed at the outlet of the appliance to guide the hot water to these sanitary facilities 

The Power of the Tankless Electric Water Heater

The power of the electric water heater must be perfectly adapted to its use to guarantee a sufficient flow of hot water.

Knowing that on average the power required to heat domestic hot water is 17 to 20 kW for a dwelling equipped with a sink, a washbasin and a shower, you will have to either use the instantaneous water heater in addition to another system. 

Or multiply the devices, since it is of course quite possible to install several instantaneous electric water heaters in different rooms of the house.

The range of instantaneous electric water heaters goes from 2 to 30 KW. Knowing that the choice of power must meet the largest flow of water points to be served, you will choose for example an electric water heater of:

  • 7 kW to power a small sink or hand basin.
  • 5 kW to power a sink or basin.
  • 5 kW to power a sink.
  • 3 kW to power a sink and a shower.
  • 9 kW to power a small bathtub.
  • 11 kW to power a bathtub.

Note that the more the power increases, the more the price of the instantaneous electric water heater increases.

The Shapes and Dimensions of an Electric Tankless Water Heater

The water heater most often takes a square or rectangular shape, even if some are rounded.

The weight and dimensions of a tankless electric water heater are much less than those of a storage water heater. These dimensions vary from the XXS format of approximately 16 cm in height for 8 cm in width and 11 cm in-depth for a 3.7 kW model, up to approximately 40 cm in height, 26 cm in width, for a variable depth.

Installation and Electrical Connection of Tankless Water Heater

The tankless electric water heater finds its place in all rooms of the house , dry as wet. With its neat aesthetics and its light weight which allows it to be fixed very simply, the electric water heater can just as easily be displayed on the wall, as it can slip under a sink  or hide in a cupboard.

Electrical Connection

It is advisable to connect your  electric water heater directly to the meter. However, depending on its power, the electrical installation constraints are not the same. 

Single-phase models (220 V) that go up to 7.3 kW must indeed be connected to a single-phase meter, while three-phase models (380 V) must be connected to a three-phase meter, which is rarer among individuals. In the latter case, you will therefore have to change your electrical installation, with the additional cost that this entails.

The meter must also be at least of the same amperage as that required by the instantaneous electric water heater, a 3.7 kW model requiring 16 amps against 32 for a 7.3 kW model.

Limit the Temperature of the Tankless Water Heater

If the tankless electric water heater heats water only on demand, avoiding waste of energy, it is nonetheless greedy in electricity, since its resistance must be powerful enough to instantly heat a certain amount of water at a given temperature.

By limiting the temperature of this water thanks to the electronic regulation system with which it is equipped, you will therefore reduce the energy consumption of your instant electric water heater from 10% to 20%. In addition, a decree fixes the temperature of water heaters between 55° and 60° C to limit the development of bacteria and microbes, as well as the risk of burns.

Why buy a Good Tankless Electric Water Heater

To save energy

Unlike a tank, the tankless water heater provides hot water on demand, without the need to conserve heat. It activates and consumes energy only when you want it to. This is very interesting for people who live alone, since it is not necessary to provide a large amount of hot water daily.

To save yourself from maintenance concerns

Since there is no hot water storage, the presence of scale, bacteria and other dirt is avoided. Otherwise reduced to a minimum. You no longer have to plan a regular cleaning tankless water heater or use a descaling product. It is also reassuring in relation to possible bacterial infections caused by water conservation.

To get hot water anywhere

Just install the instant water heater where you want it. Its small size makes it easy to mount and to supply hot water to off-center locations. Unlike conventional balloons, its use does not involve long passages in pipes. The water is directly heated where it will be discharged.

To ensure your comfort without bulky installations

This type of water heater consists of a compact unit, which fits easily in a small area. Ideal for small apartments, it allows you to enjoy hot water at a satisfactory rate without cluttering up with large equipment. In addition, installation tankless water heater is very easy if your hydraulic system is already compliant (no related work).

To benefit from durable equipment

Ordinary water heaters have an average lifespan of 10 to 15 years. The instantaneous electric water heater, for its part, lasts up to 20 years or more. This is an important advantage, you invest in a device which is not likely to be damaged after some time.