5 Best Electric Tankless Water Heater Reviews (Updated 2023)

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Electric Tankless Water Heater Reviews

Electric tankless water heaters are designed to instantly heat your home’s water supply without the need for a storage tank. We’ve researched and reviewed the five top-rated electric tankless water heaters on the market, as well as one to avoid.

What are the best electric tankless water heaters on the market?

✅ 1. EcoSmart ECO 36 Learn More

✅ 2. Rheem RTEX-18 Learn More

✅ 3. EcoSmart ECO 11 Learn More

✅ 4. Stiebel Eltron Tempra 24 Plus Learn More

✅ 5. Marey Eco 110 Learn More

Reviews of the 5 Best Electric Tankless Water Heaters, Plus 1 to Avoid

1. EcoSmart ECO 36

Ecosmart ECO 36 Review

EcoSmart ECO 36 Review: Best Electric Tankless Water Heater for Cold Climates With the purchase of the EcoSmart ECO 36 you get a lot of amazing performance features.

First, the EcoSmart ECO 36 is the largest tankless water heater in the EcoSmart lineup. If you require a high demand of hot water to the home, up to 6 gallons per minute, the Eco 36 can do the job with ease. That equates to four showers and a sink receiving hot water simultaneously. ECO 36 is great for large jacuzzis and hot tubs too!

Second, EcoSmart ECO 36 heats the water your home needs, “on-demand.” That means no wait time. And finally, the ECO 36 uses patented auto-controlled energy consumption technology to meet the home’s demand for hot water while providing 99.8% thermal energy efficiency.

ECO 36 measures 3.6” D x 21” H x 17” W inches and weighs 18 pounds. You’ll save up to 16 cubic feet of space with the wall-mountable design.

The all-weather ECO 36 tankless water heater is built using copper and stainless steel components, providing between 2.7 and 6.5 gallons-per-minute per the home’s inlet water flow, and can heat water at 3.5 gallons per minute even when external temperatures reach 37° F.

Get the quantity of hot water you need, when you need it, at the exact temperature you need it using the ECO 36 digital temperature control system. ECO 36 is so intuitive, it can get the water temperature within +/- 1°F.

Ecosmart uses field-replaceable unit (FRU) printed circuit board technology for quick removal and replacement without having to send the unit or parts to the manufacturer for repair.

Warranty: EcoSmart offers customers a Limited Lifetime Warranty after the ECO 36 is installed by a technician or plumber and registration of the product within 30 days of purchase.

To watch the EcoSmart ECO 36 Review on YouTube, click here.


  • Robust and comprehensive online resources provided by the manufacturer
  • ECO 36 multi-user high-efficiency capability provides a continuous flow of hot water throughout the home
  • Continual hot water flow reaches tap within 15 seconds


  • Copper tubing overheated and scorched part of the unit
  • Dedicated fuse is essential to avoid continually blowing fuse box
  • More than 2 hot water destinations running simultaneously doesn’t provide enough hot water


2. Rheem RTEX-18  

Rheem RTEX 18 Review

Rheem RTEX-18 Review: Best Electric Tankless Water Heater Under $500 The Rheem RTEX-18 meets and exceeds all expectations, and the price tag under $500 doesn’t skimp on the value or quality.

RTEX-18 offers a 4.4 gallon per minute (GPM) flow rate whether you’re using this tankless electric water heater as a single-point or for whole-home use.

The Rheem RTEX-18 is a space-saving, hard-working electric tankless water heater and has shown to continually provide hot water in 2,500 sq. ft. four bedrooms, three bathrooms home. Never wait for the tank to heat up!

The RTEX-18 wall-mounted unit measures 14.5” W x 3.5” D x 18.25” H, weighs 15 pounds, and a well-crafted FRU circuit board with copper, stainless steel, and coated silicone tubed wire coatings.

RTEX-18’s state-of-the-art digital has a one-touch temperature dial for precise +/- 1° F temperature control.

Warranty: Rheem offers customers a 6-year Limited Lifetime Warranty (5-year heating chamber, 1-year parts) after the installation, and the product must be registered within 90 days of purchase.

To watch the Rheem RTEX-18 Review on YouTube, click here.


  • Easy installation; a well-built, reliable tankless water heater
  • Continual flow of hot water on demand
  • Energy saving water heater fires up ONLY fire when hot water is needed


  • Not as efficient in extremely cold climates
  • Extra installation costs by a profession due to the mounting and wall diagrams being printed upside down
  • Very limited warranty and minimal product information on manufacturer’s website


3. EcoSmart ECO 11 

Ecosmart Eco 11 Review

EcoSmart ECO 11 Review: Best Electric Tankless Water Heater for RV If camping, traveling, or off-the-grid living is your thing, the ECO 11 from EcoSmart is a sure bet. Measuring less than a foot at 11.5” H x 8” W x 3” D, weighing 6 pounds, this tiny but mighty tankless electric water heater can save you up to 60% on your current energy usage.

Built using the same copper and stainless-steel components, ECO 11 uses an 11.8-kilowatt tankless electric water heater that is perfect for heating small single-unit apartments, cabins, boats, and of course, RVs.

EcoSmart ECO 11 is on-demand water heating performance provides between 1.3 and 3.1 gallons-per-minute (2 GPM) per the RV inlet water hookup. EcoSmart’s Proprietary Smart Technology™ is built-in to heat the water to continually heat the water when and where you need it.

Warranty: EcoSmart offers customers a Limited Lifetime Warranty after the ECO 11 is installed by a technician or plumber AND registration of the product within 30 days of purchase.

To watch the EcoSmart ECO 11 Review on YouTube, click here.


  • Expect all the performance and efficiency as the larger EcoSMart electric tankless water heater models
  • Can replace up to a 40-gallon tank water heater and gain more space in the garage or RV
  • Very impressive energy savings up to 60%


  • Prone to tripping the home’s circuit breaker
  • Mineral build-up can cause the heating rods to be cleaned regularly to keep the heater in top performance
  • Difficulty receiving replacement parts and slow-to-respond customer service requests


4. Stiebel Eltron Tempra 24 Plus

Stiebel Eltron Tempra 24 Plus Review

Stiebel Eltron Tempra 24 Plus Review: Best Electric Tankless Water Heater for Large Families Stiebel, a leader in energy-saving technology since 1924, offers the best electric tankless water heater for large families.

The Stiebel Eltron Tempra 24 Plus uses Stiebel’s patented Advanced Flow Control™ technology allowing this tankless water heater to deliver slightly less water than competitor brands. It will consistently deliver the desired hot water temperature without a “cold water surprise.” And it never compromises the water pressure.

A built-in microprocessor is so intuitive it can detect flow sensitivity throughout the home. Eltron Tempra 24 Plus will ensure a consistent output temperature no matter if the water flow rate increases or decreases.

The German-made Stiebel Eltron Tempra 24 features a solid copper heating chamber and a pre-set temperature control system giving you the ability to set precise hot water temperatures between 68°F and 140°F.

Warranty: Stiebel offers customers a 7-Year Leakage and 3-Year Parts Warranty, respectively, with purchase. Registration of the product is recommended.

To watch the Stiebel Eltron Tempra 24 Plus Review on YouTube, click here.


  • Very easy, no-cost installation
  • So whisper-quiet, owners forget they have a water heater
  • Easy-to-use interface, and has provided 10+ years of reliable tankless hot water output


  • Flow rate is not as robust as the manufacturer promises.
  • Depending on the house square footage, the unit may require extra, costly electrical installation.
  • Unit will not turn on if your home’s flow through fixture is a minimum of .5 – .8 gallons a minute.


5. Marey Eco 110

Marey Eco 110 Review

Marey Eco 110 Review: Best Small Electric Tankless Water Heater Marey builds their small electric tankless water heaters with all the impressive capabilities of larger competitive models. ECO 110’s design continually heats the water at 3 GPM without interruption or loss of water pressure, or unexpected electrical surges.

The Marey ECO 110 is tiny but mighty design measures 3.1” D x 7.5 W x 10.8” H and weighs only 7.5 pounds.

Marey uses SMART Technology for easy management and to make simple adjustments to the built-in LCD Panel. Choose exact desired water temperatures and simultaneously optimize your electricity consumption.

Very impressive results for a small tankless electric water heater!

Warranty: Marley offers an industry-leading 5-year warranty. Registration of the unit is recommended.

To watch the Marey Eco 110 Review on YouTube, click here.


  • Immediate two-faucet point-of-entry entry hot water flow
  • Easy-to-install to home’s current plumbing
  • Noticeable energy savings when the unit replaced 170 30-gallon tank-style heaters in an apartment complex


  • Water flows noticeably hotter when used with a two-handle faucet
  • Difficult to contact customer support for replacement parts and warranty questions
  • “On demand” hot water gets hot, but stays hot only 65% of the time after the unit turns on


Avoid – Bosch Tronic 3000

Bosch Tronic 3000 Review

Bosch Tronic 3000 Review At first glance, it’s easy to confuse the Bosch Tronic 3000 with a large SmartPhone. It costs about the same too! Can an electric tankless water heater this small and this inexpensive offer the same seamless on-demand hot water performance as the others in this review?

On the one hand, this 0.3 GPM electric under-the-sink tankless water heater is designed to be a space saver. It measures a mere 6.6″ x 12.8″ x 2.9″ and weighs under 9 pounds.

Even in the tightest of space, Bosch Tronic 3000 can be easily installed using its unique 360-degree angle design.

On the other hand, the important power cord isn’t included with the purchase. Also, each unit has to be placed as close to the sink or appliance as possible.

With the Tronic 3000, you have an individual flow rate (and have to understand what they are) for each unit you install versus one electric tankless water heater, with a higher flow rate, moving more GPM of hot water towards the destination(s) where you need hot water on demand.

While this tankless electric water heater might be great for individual sinks at shopping malls, airports, stadiums, and offices, the amperage requirement makes each unit have to be hard-wired separately.

That can account for costly installation.

Perhaps future iterations of the Bosch Tronic 3000 will reveal better functionality and longer, more consistent water heating times. Until then, this model is one to avoid.

Warranty: Bosch offers a 5-year limited warranty.

To watch the Bosch Tronic 3000 Review on YouTube, click here.


  • Immediate one faucet point-of-entry entry with moderately consistent hot water flow
  • Good for both residential and light-commercial low-flow faucets
  • Unique 360-degree installation design lets the unit fit into the tightest spaces


  • Required power cord not included with purchase
  • Can’t heat up a standard bathtub full of water
  • No numerical LED temperature control system


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2022 Buyers Guide to the Best Electric Tankless Water Heater

Washing dishes require warm water to ensure grime can be effectively removed and bacteria can be destroyed. You use warm water for food to ensure the water can boil faster, resulting in less cooking time.

Buying an electric tankless water heater vs a gas or propane tankless will give you instant access to unlimited warm water in your kitchen, laundry room and bathroom. There is no need to worry about having to maintain a full tank, and you get the benefit of lowering your power consumption.

Before you make a final decision, there are some elements that need to be taken into account to ensure you buy the most appropriate water heater for your requirements.

3 Main Points to Consider:

  • Size of the heater: The size of the electric tankless water heater that you buy will play a role in determining whether it will be easy to install. Buying an electric tankless water heater that is larger than the space you currently have, means you will have to make certain adjustments.Adjusting for space can be unpleasant and even lead to additional costs – since you are trying to save money with an electric tankless water heater, you want to keep the initial installation costs as low as possible.We recommend first considering where you want to install the heater and consider the space you have available for the water heater, and then to start looking for an option that will fit into this space. Electric tankless water heaters vary widely in size, so there is sure to be one that fits into the space you have available.
  • Maintenance required by the heater: Lower maintenance requirements equal fewer expenses for ensuring an electric tankless water heater can continue operating without any problems.While older models of these tankless water heaters tend to build up substances within them, such as limescale, newer models on the market tend to utilize special technology that helps to reduce the buildup of limescale within the system.In turn, this means you will not need to spend as much money on the maintenance of the electric tankless water heater as compared to an option that will constantly cause limescale to build up in the pipes. Heaters fitted with infrared technology is one example of how limescale buildups can be reduced, and maintenance costs can be lowered significantly. Even though these models may cost somewhat more than an older heater, they will provide you with better value for your money in the long run.
  • Configurations offered by the heater: Some electric tankless water heater will come with a single default setting build into the device, while others will allow for the configuration of the system. It is essential to consider this option as opting for a tankless with only one single setting might be unpleasant when the water becomes too hot or when you find that the water that comes from the device is not hot enough.A water heater that offers you the ability to configure the particular settings, including the temperature that water should be heated to, will ensure you get access to water that is just the right temperature – not too hot and not too cold. This can be very useful when washing dishes and even when cooking, as warm water is something that we constantly use in the kitchen, but we may sometimes require different temperatures of warm water to suit the particular activities they will be used in.

What makes electric tankless water heaters more energy efficient?

Electric tankless water heaters are highly efficient units, which eliminate the standby loss and provide a consistent flow of hot water. Traditional tank-style water heaters reheat the same water repeatedly and raises energy costs.

While an electric tankless hot water heater is a considerably significant investment, the lifespan of owning a tankless water heater versus a tank-style water heater is just as significant.

That formidable, noisy, space-taking tank in the garage has a lifespan of about ten years, while a tankless model can function twice as long! As far as efficiency, you can expect a tankless water heater to be 22% more efficient. That efficiency can qualify you for federal tax breaks, too. Up to a 10% tax credit, as of 2016.

One of the primary reasons why so many people are starting to switch from traditional tank heaters to tankless water heaters is due to the energy efficiency offered by these devices. When it comes to the time spent in the kitchen, there are different ways in which the installation of an electric tankless water heater can help you save money on your utility bills.

Firstly, these water heaters only consume power when they are put into action – this means that, when the tap is not open, the device will be switched off. Since there is no tank full of water that needs to be kept warm throughout the day, it means much lower utility bills since a tank heater will continuously consume power.

Additionally, also think about the time you will save during cooking – and, of course, on your electric bill at the same time. When you start off with warm water, your food can get cooked faster – this means your stove will be on for a shorter period of time.

Final Thoughts on Buying an Electric Tankless Water Heater

Recent trends data shows an interest in owning an electric tankless hot water heater has more than doubled in recent years. That’s because electric tankless water heaters offer many benefits over traditional tank heaters, with the primary advantage being the fact that they can save you a significant amount on your monthly utility bills.

You can rest easy knowing that an electric tankless water heater works on demand, delivering hot water when and where you need it without the cold-water surprise! No matter the size of your home, and the demand for hot water, owning an electric tankless water heater is optimal for many reasons.

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*Additional Water Heater Reviews*

Gas Tankless Water Heaters
Electric Water Heaters
Tankless Water Heaters
Rheem Water Heaters
50-Gallon Gas Water Heater
Tankless Water Heaters for RV
Propane Tankless Water Heater
50-Gallon Electric Water Heater

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