A water heater attached to a teal colored wall.

Best Electric Tankless Water Heater Reviews of 2021

Hot water is a very important necessity in your home. Having a proper heating system for your water supply that is both efficient and gives you on-demand hot water without racking up your utility bills. Homeowners all around America and the world have been turning to both tank water heaters or the more efficient tankless water heaters in order to heat up their homes. Hot water is essential to hot showers and everyone knows the value of a hot shower after a long day at work.

Hot water can help you clean your clothes better, and it can help you clean your dishes better. Hot water is as much a privilege as a necessity. A tankless unit works by changing the incoming water temperature using either propane and natural gas or water heating elements, causing a temperature rise from cold water to hot. Most water heaters also have a temperature control feature that lets you choose which temperature you would like your water at.

Without a storage tank, these water heaters are more space-saving and more budget-friendly, spending less energy and therefore lowering your energy bills. If you want to learn more about electric tankless hot water heaters, the US government’s energy department website has quite a thorough read. In case you have read all you need and are ready to get started and get a tankless hot water heater for your home, we have developed a buying guide. You can finally take care of all your home improvement and hot water needs!

In a hurry? Here’s the test winner after 10 hours of research:

Overivew
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Title
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Price
$599.00
Rating
Overivew
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Title
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Price
$599.00
Rating

Best Electric Tankless Water Heater Reviews of 2021 – Overview

Here are the top 5 picks (keep scrolling for more details and picks 6-10).

Overview
Best Overall
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, small, Gray
Rheem 240V 4 Heating Chambers RTEX-36 Residential Tankless Water Heater, GRAY
Lowest Price
Marey Power Pak Plus Tankless Electric Water Heater, 220 VOLT
Stiebel Eltron 239223 Tankless Water Heater – Tempra 29 Plus – Electric, On Demand Hot Water, Eco, White, 23
Title
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, small, Gray
Rheem 240V 4 Heating Chambers RTEX-36 Residential Tankless Water Heater, GRAY
Marey Power Pak Plus Tankless Electric Water Heater, 220 VOLT
Stiebel Eltron 239223 Tankless Water Heater – Tempra 29 Plus – Electric, On Demand Hot Water, Eco, White, 23
Price
$599.00
$412.00
$825.00
$145.69
$621.81
Rating
Best Overall
Overview
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Title
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Price
$599.00
Rating
Overview
Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, small, Gray
Title
Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, small, Gray
Price
$412.00
Rating
Overview
Rheem 240V 4 Heating Chambers RTEX-36 Residential Tankless Water Heater, GRAY
Title
Rheem 240V 4 Heating Chambers RTEX-36 Residential Tankless Water Heater, GRAY
Price
$825.00
Rating
Lowest Price
Overview
Marey Power Pak Plus Tankless Electric Water Heater, 220 VOLT
Title
Marey Power Pak Plus Tankless Electric Water Heater, 220 VOLT
Price
$145.69
Rating
Overview
Stiebel Eltron 239223 Tankless Water Heater – Tempra 29 Plus – Electric, On Demand Hot Water, Eco, White, 23
Title
Stiebel Eltron 239223 Tankless Water Heater – Tempra 29 Plus – Electric, On Demand Hot Water, Eco, White, 23
Price
$621.81
Rating

 

Best Overall
1. Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater

Sale
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
408 Reviews
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
  • Sleek and compact design with digital output temperature display

The Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater is the absolute best on the market. It boasts a fantastic price-to-quality ratio. As with most electric tankless water heaters, the Ecosmart’s capacity changes depending on what kind of climate you live in. In warm climates, this hot water heater’s capacity is 9 GPM (meaning gallons per minute). In colder climates, this heater’s capacity is 3.6 gallons per minute.

This Ecosmart model is 99.8 percent energy-efficient, so you will be saving money purchasing this model. It is a sleek and compact model that boasts a digital output temperature display, so you can know how hot the water is coming out of this system and change the water temperature.

 

Features of the Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater:

  • Best on the market
  • Great price-to-quality ratio
  • A capacity of 9 GPM in warm climates
  • A capacity of 3.6 GPM in colder climates
  • 99.8 percent energy efficient
  • High energy savings
  • Sleek and compact design
  • Digital output temperature display
  • Made in the USA
  • Pipe fittings are 3/4 inch NPT
  • Comes with a limited lifetime warranty

 

2. Rheem RTEX-18 18kW 240V Electric Tankless Water Heater

Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, small, Gray
715 Reviews
Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, small, Gray
  • External digital thermostatic control with LED display (+/1 degree accuracy)

The Rheem RTEX-18 18kW 240V Electric Tankless Water Heater is an easy-to-install electric tankless water heater. It boasts an advanced self-modulation process that conserves energy when there is less demand for hot water, meaning that this electric water heater will reduce the need for electricity in your home by 50 percent. This heater also contains an external digital thermostatic control with a clear LED display so you can check the temperature of the system and change it at will with an accuracy of ±1°F. It also has durable dual copper immersion elements, meaning this is not a gas tankless water heater.

This electric tankless water heater has two different sets of warranty – a five-year warranty for the heating chamber, and a one-year warranty for parts. There are only a few downsides to this system. This water heater is possible to lose efficiency if it is connected to too many fixtures, so you might not be able to use it for your whole house. This system is also a bit on the expensive side.

 

Features of the Rheem RTEX-18 18kW 240V Electric Tankless Water Heater:

  • Advanced self-modulation that uses more power when heating demands it and conserves energy when demand drops
  • A water flow rate of 4.4 GPM
  • Reduces the need for electricity by 50 percent
  • External digital thermostatic control with a clear LED display
  • Durable dual copper immersion elements
  • A five-year warranty for the heating chamber
  • A one-year warranty for parts
  • Easy to install
  • 3/4 inch NPT water connections
  • Might lose efficiency if plugged into too many fixtures
  • Not a very budget-friendly option
  • Batteries not required

 

3. Rheem 240V 4 Heating Chambers RTEX-36 Residential Tankless Water Heater

Rheem 240V 4 Heating Chambers RTEX-36 Residential Tankless Water Heater, GRAY
51 Reviews
Rheem 240V 4 Heating Chambers RTEX-36 Residential Tankless Water Heater, GRAY
  • External digital thermostatic control with LED display (+/1 degree accuracy)

The Rheem 240V 4 Heating Chambers RTEX-36 Residential Tankless Water Heater is a compact unit with four copper heating immersion elements and an external digital display with an LED readout for changing the heater’s temperature. This system also contains an advanced self-modulation process that will reduce the need for electricity in your home by 50 percent. This is yet another Rheem system that is very similar to the one mentioned above, only on a larger scale.

This is a very easy-to-install system that requires 150 amps to run. This unfortunately might not be accessible for every home, which is an unfortunate downside to this electric water heater. As with the system above, there is a warranty of five years for the heating chambers and a warranty of one year for the parts. And similarly, as with the electric tankless water heater above, it is a fairly expensive system and might not be the best option for someone on a lower budget.

 

Features of the Rheem 240V 4 Heating Chambers RTEX-36 Residential Tankless Water Heater:

  • Four copper heating immersion elements
  • Advanced self-modulation system
  • Reduces the need for electricity by 50 percent
  • External digital display with the LED readout
  • Compact unit
  • Easy installation
  • 3/4 inch NPT water connections
  • Warranty of five years for the heating chamber
  • Warranty of one year for parts
  • Requires 150 amps to run which might not be accessible to every home
  • More expensive than other models
  • Batteries not required

 

Lowest Price
4. Marey Power Pak Plus Tankless Electric Water Heater

Sale
Marey Power Pak Plus Tankless Electric Water Heater, 220 VOLT
116 Reviews
Marey Power Pak Plus Tankless Electric Water Heater, 220 VOLT
  • Allows customer to regulate energy consumption, adapting the product to the home’s electric capacity

The Marey Power Pak Plus Tankless Electric Water Heater is an easy-to-install and easy-to-use electric tankless water heater that can save you up to 60 percent on electricity. This is a budget-friendly option that also boasts a water filter, which is a fantastic plus. A water filter will make sure you get clean, pure water, without any of the impurities commonly found in tap water.

This electric water heater’s capacity changes depending on the type of climate you live in. In a hot climate, you can use this heater with two fixtures. In a cold or a moderate climate, you can use this system with only one fixture. The only downside to this system is that it does not have the capacity to heat up an entire bathtub for a bath, since baths have higher water flow rates than showers, and this system will not have the ability to heat the water fast enough.

 

Features of the Marey Power Pak Plus Tankless Electric Water Heater:

  • Budget-friendly option
  • Easy to install
  • Easy to use
  • High energy efficiency
  • You will save up to 60% on electricity
  • Comes with a water filter
  • Can be used with two fixtures at once in hot climates
  • Can be used with one fixture in cold/moderate climates
  • Does not have the capacity to heat a bathtub for a bath

 

5. Stiebel Eltron Tempra Plus 29 kW Electric Tankless Water Heater

The Stiebel Eltron Tempra Plus 29 kW Electric Tankless Water Heater is a great product from this well-respected German brand, which has been around for almost 100 years. This electric tankless water heater comes with advanced flow control technology as well as self-modulation technology. This system will reduce 15 to 20 percent of your electricity use. There are a few problems with this system. Its flow rate might lower when demand exceeds supply.

It is also a fairly complicated water heater system to install, so in the case that you are not prepared to put in the amount of electrical work you have to do in order to get it up and running, you might want to either get yourself a plumber or choose a different electric, tankless water heater. Lastly, this product can sometimes struggle if it is run on several fixtures at once in a cold climate.

 

Features of the Stiebel Eltron Tempra Plus 29 kW Electric Tankless Water Heater:

  • Advanced flow control technology
  • Reduces flow slightly when demand exceeds supply
  • Self-modulation technology
  • Reduces 15 to 20 percent of electricity use
  • The sleek design saves space
  • There is no venting required
  • No batteries are needed
  • It will require a certain amount of electrical work in order to install it
  • Might struggle with running several fixtures at once in winter in cold climates

 

6. Eemax EEM24027 Electric Tankless Water Heater

Sale
Eemax EEM24027 Electric Tankless Water Heater, Blue
86 Reviews
Eemax EEM24027 Electric Tankless Water Heater, Blue
  • Tank less water heaters provide a continuous Supply of hot water and only heats the water you need, when you need it

The Eemax EEM24027 Electric Tankless Water Heater is a compact product also available in smaller sizes, so you can customize it to the size of your home. It also boasts self-modulation technology that will save you money on electricity. It is a very easy-to-install electric tankless water heater. If you live in a place with a cold climate, this system should be able to provide you with hot water for a shower and two sinks faucets.

If you live in a place with a warm climate, you should be able to have hot water for four showers or four sinks faucets. Running a bath might be difficult with this product due to its low flow rate. This water heater can also be an expensive product for some households.

 

Features of the Eemax EEM24027 Electric Tankless Water Heater:

  • Self-modulation technology
  • Compact design
  • Easy to install
  • Can provide hot water for a shower and two sinks in cold climates
  • Can provide hot water for four showers or four sinks in warm climates
  • It is also available in smaller sizes
  • Running a bath might be difficult due to the flow rate
  • Can be an expensive product

 

7. Atmor AT-910-27TP ThermoPro Electric Tankless Water Heater

Atmor AT-910-27TP ThermoPro 27kW/240V Electric Tankless Water Heater, 5.1GPM 112.3 Amps
264 Reviews
Atmor AT-910-27TP ThermoPro 27kW/240V Electric Tankless Water Heater, 5.1GPM 112.3 Amps
  • Digital temperature control allows you to set your temperature in increments of 1 degree. Thermostatic control range from 90-135 degrees

The Atmor AT-910-27TP ThermoPro Electric Tankless Water Heater is a reliable Atmor product and a great budget-friendly option with a stainless steel interior that makes sure this heater’s lifespan is long. This electric water heater can heat water from 90 to 135 degrees. If you live in a warmer climate, this electric tankless water heater’s capacity should be 4.6 GPM. If you live in a colder climate, this water heater’s capacity should be 2.45 GPM.

 

Features of the Atmor AT-910-27TP ThermoPro Electric Tankless Water Heater:

  • Digital temperature control
  • Thermostatic control range from 90-135 degrees
  • 4.6 GPM capacity in warmer climates
  • 2.45 GPM capacity in colder climates
  • Stainless steel interior
  • Budget-friendly option

 

8. Rinnai V65IN Tankless Water Heater

Rinnai Indoor Tankless Hot Water Heater / V65iN / Natural Gas / 6.3 GPM, Large, V65iN-Natural 6.5
974 Reviews
Rinnai Indoor Tankless Hot Water Heater / V65iN / Natural Gas / 6.3 GPM, Large, V65iN-Natural 6.5
  • Energy and Space Efficient: Space-saving design conserves energy as it heats only when necessary

The Rinnai V65IN Tankless Water Heater is the ideal choice for either small homes or mobile homes. It is able to produce up to 6.5 gallons of heated water per minute in warm weather and might be capable of working with up to five different fixtures at the same time. The most impressive part about this water heater is that it can detect scale buildup and will shut the product down to prevent overheating damage. There are several types of warranties that come with this product. There is a warranty for 120 months on the heat exchanger, a warranty for 12 months on the labor, and there is a warranty for 60 months on the product’s parts.

 

Features of the Rinnai V65IN Tankless Water Heater:

  • Ideal for small or mobile homes
  • Can be capable of serving up to five different fixtures at the same time
  • May be able to produce up to 6.5 gallons of heated water per minute in warm weather
  • Detects scale buildup and will shut the appliance down rather than risk overheating damage
  • Warranty of 120 months on the heat exchanger
  • Warranty of 12 months on the labor
  • Warranty of 60 months on the parts

 

9. Bosch ES4 Tronic 3000

Sale
Bosch Electric Mini-Tank Water Heater Tronic 3000 T 4-Gallon (ES4) - Eliminate Time for Hot Water - Shelf, Wall or Floor Mounted
5,578 Reviews
Bosch Electric Mini-Tank Water Heater Tronic 3000 T 4-Gallon (ES4) - Eliminate Time for Hot Water - Shelf, Wall or Floor Mounted
  • CONVENIENT HOT WATER HEATER: 4 gallon point-of-use mini-tank fits under your sink to provide hot water right where you need it. Thermal efficiency is 98%. Dimensions : 13.75 W x 13.75 H x 13.5 D...

The Bosch ES4 Tronic 3000 is a lovely small electric tankless water heater. It is a 4-gallon point-of-use mini-tank that boasts a thermal efficiency of 98%. It can supply up to two sinks at the same time. Seeing as this is a smaller, more compact system, you have more options on where to place it. You will receive mounting equipment so you can mount it on a shelf, a wall, or a floor. It can also be placed on a countertop or under a sink.

 

Features of the Bosch ES4 Tronic 3000:

  • 4-gallon point-of-use mini-tank
  • Thermal efficiency is 98%
  • Supplies up to 2 sinks at a time
  • Can be shelf, wall or floor mounted
  • Mounting equipment included
  • Can be placed on the countertop or under the sink

 

10. AO Smith ATO-310-P

The AO Smith ATO-310-P is a sturdy product. It has a built-in freeze protection system and an inlet and an outlet thermistor that will allow you to monitor the temperature that the heater is at. You can also install a temperature remote control so you do not have to change the temperature at the heater every time. This electric tankless water heater is able to supply two fixtures in your home at the same time. This water heater has no need for batteries, making it more energy-efficient.

 

Features of the AO Smith ATO-310-P:

  • Built-in freeze protection
  • Inlet and outlet thermistors so you can monitor the temperature
  • Can supply two fixtures at the same time
  • Temperature remote control can be installed
  • No need for batteries

 

Our Winner:

Overivew
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Title
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Price
$599.00
Rating
Overivew
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Title
Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater
Price
$599.00
Rating

The Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater is our winner and our absolute favorite on this list. It has a fantastic price-to-quality ratio with a great flow rate. It is 99.8 percent energy-efficient and it is a compact and pleasing design. For these reasons and more, this is the winner in the electric tankless water heater category.

 

Bonus Tip: Check out this great video on the differences between tank and tankless water heaters!

 

 

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Joshua Perkins

Joshua spent ten years as a water systems technician in California before settling down with his wife and two young children in Nashville in 2018. Through all of his experience, he learned the benefits and shortfalls of so many different types of water filtration systems, from pitchers to whole-house installations. He started Water Filter Authority in 2019 to empower other families to make the right decision for their long-term health and wellness.