8 Best Electric Tankless Water Heaters That Provide Quick Results

best electric tankless water heater

If you’re looking for a reliable & efficient way to get hot water in your home, then an electric tankless heater is the perfect solution. These devices provide a steady stream of hot water on demand and require no storage tanks, saving you a lot of money on your water-heating costs. There are so many options on the market, so choosing the best electric tankless water heater can be hard. 

To help you narrow it down, I’ve put together a comprehensive list of the top electric tankless water heaters on the market, highlighting the features and benefits of each one to help you make the best decision. Whether you’re looking for a model with advanced features or a budget-friendly model, you’ll find the best electric tankless water heater in this list.

Comparison Of Best Tankless Water Heater






EcoSmart ECO 18

Save 60% on your water heating costs, Most advanced, self modulating technology, Save up to 12 cubic feet of storage space


4.5 / 5 

EcoSmart ECO 27

Endless on-demand hot water, ac_dc power source, 3 gallons capacity


4.4 / 5 

EcoSmart ECO 11

99% thermal energy efficient, Consistent hot water, 2 gallons capacity


4.4 / 5 

Rheem RTEX-18

4.4 GPM flow rate, 18 kilowatts capacity, AC/DC power source


4.4 / 5 

Stiebel Eltron Tempra 24 Plus

Eco friendly unit saves energy, Small and sleek white design, Easy to operate


4.6 / 5 


Instant unlimited hot water, Self-modulating technology, Stable water temperature


4.2 / 5 

Rheem RTEX-13

Battery powered source, 99.8% energy efficient, 13 KW


4.4 / 5 

Stiebel Eltron DHC 3-1

Resettable safety high limit switch, Battery powered source, Instant hot water


3.9 / 5 

How I Chose The Best Electric Tankless Water Heater

one of the best electric tankless water heaters on the market

Before choosing the best electric tankless water heater, you must consider the following criteria: 

Sizing (Temperature Rise & Flow Rates)

When selecting a tankless electric water heater for the whole house, the first step is to determine the correct size.

The size of your perfect system depends on the number of people living in your residence, their water usage habits, and the number of bathrooms and hot-water devices such as a dishwasher and a washer.

The size of the hot water system depends on the hot water you require during periods of highest usage.

If you opt for a small water heater, you can save on space. But, you’ll likely experience a decrease in the hot water volume, so you’d need to use less of it, or it will be less hot. On the contrary, buying a large heater would lead to excessive spending.

When you’re selecting an electric tankless water heater, you should consider the location where you live. This will determine the incoming water temperature. The required temperature increase is greater if you reside in a colder area.

In the southern states, the incoming water temperature is higher. However, when it is winter in the north, it might not be possible to take two hot showers without a decrease in the hot water pressure or a decline in the water temperature.

Generally, the further north a residence is located, the greater the size of the required water heating system.


Not everyone considers the design of a unit, though I see it as a minor factor. A well-crafted design can be worth its weight in gold.


It is essential that the water heater you choose is simple to operate. In addition, the device must provide the possibility to change the temperature of the discharged water by turning a knob or pushing button.


It is essential to have ample space in the house to install a tankless water heater. Heaters designed for individual outlets can be placed in many places, for example, inside a restroom closet. POE models, however, are not suitable for limited spaces.

Energy Efficiency

The energy efficiency of electric tankless water heaters is at least 95%. Therefore, the energy efficiency of the water heater has a minimal impact. You can look at its Energy Factor (EF) rating to gain insight into a system’s energy conversion efficiency. High rating products are more efficient in energy consumption & lead to less energy wastage.

Advantages Of The Best Electric Tankless Water Heater

Here are the advantages of the best electric tankless water heater: 

  • 95% efficiency – If you investigate, you will discover that electric tankless heaters typically possess an energy efficiency rating of 95% or better. Nearly all the energy converts into heat, which is incredibly efficient.
  • Hot water on demand – If you have a conventional water heater, it will cease to produce warmth once it is out of hot water. However, a tankless system guarantees a continuous supply of hot water.
  • Don’t worry about venting – Electric tankless water heaters don’t need venting.
  • On-demand heating without standby losses – An electric tankless water heater is a demand-based system. Rapid heating provides much higher energy efficiency due to the complete absence of standby losses.
  • Long lifespan – Electric tankless water heaters heat the water & store it for later use. It has a long lifespan.
  • Flexible installation – Electric tankless water heaters are relatively small and easily fit in tight spaces.
  • Low costs and utility bills – Electric tankless water heaters are more affordable than gas-powered units in terms of initial cost and installation expenses. You’ll save money by only paying for the hot water you use.

Types Of Best Electric Tankless Water Heater

Here are the two electric tankless water heaters types: POU and POE.

Point-Of-Use Electric Tankless Water Heaters

POU (Point of Use) electric tankless water heaters provide a single source of heated water, such as a faucet in a bathroom. These devices are tiny and can fit into almost any tight space, for instance, in a bathroom cupboard.

Whole House Electric Tankless Water Heaters

A whole house water heater warms the water for an entire residence, so POE models are unsuitable for cramped areas.

It is necessary to remember that not all residences are compatible with this type of system due to the high electric current requirement.

It is possible that your current electric service panel needs updating with thicker wiring and larger circuit breakers, or you may have to completely replace it, costing around a couple of thousand dollars for the electrical job.

Best Electric Tankless Water Heater In 2023

1. EcoSmart ECO 18


  • Save 60% on your water heating costs
  • Most advanced, self modulating technology
  • Save up to 12 cubic feet of storage space
  • ac_dc power source
  • 18000 watts



+ Great hot water system
+ Excellent product
+ Unmatched quality
+ Very good design
+ Easy to install
+ Highly durable
+ Affordable
– Customer service needs improvements

The Ecosmart ECO 18 Water Heater is a widely popular medium-sized tankless water heater. It has received favorable feedback from both experts and regular feedback. This model has the necessary characteristics and technology to guarantee its reliability for a long time.

People who reside in areas that experience cold temperatures typically opt for natural gas water heaters. If the water temperature is comparatively warm (around 62°F), then the ECO 18 is a desirable model.

This system can heat 2.5 gallons of water in a single minute to a temperature of 105 degrees if the initial temperature of the water is near 60 degrees.

Unlike conventional water heaters, the ECO 18 does not keep water at a pre-set temperature. On the front of the unit is a temperature control knob that allows you to modify the water temperature one degree at a time.

Reviews from customers


Schrimpieman, a resident of the USA, loved the Eco-18 water heater. He gave the Eco-18 a number “9” on a scale of 1 to 10. He said, “Eco-18 water heater has a small package size and space savings compared to a conventional 40-gallon tank. Hang it on the wall, make the connections, set it once, and forget it. Hot water forever.”

Harold Stone, mentioned that he is delighted with the Eco-18 water heater and would never return to a tank. He said that “ This unit is well-built and easy to install. The unit’s piping is all copper, not steel, as in tanks. The controls are simple, and easy to set the temperature. With the right plumbing, it is simple to flush the system, big plus over tanks.”

2. EcoSmart ECO 27


  • Save up to 12 cubic feet of storage space
  • 200 Amps electrical panel (recommended)
  • Three 40 Amp Double Pole breaker quantity (required)
  • Endless on-demand hot water
  • ac_dc power source
  • 3 gallons capacity



+ Well-designed product that delivers a steady water temperature
+ Works great in the Northwest climate
+ Energy-efficient heater
+ Excellent water heater
+ Easy installation
– Causes other electrical issues

The EcoSmart ECO 27 provides competitive performance with a maximum of 6.5 GPM. It has a 0.3 GPM minimal activation requirement. So, users don’t need to turn faucets on full power to get hot water.

EcoSmart ECO 27 electric water heater offers optimal control. It utilizes flow adjustment on heating water. 

This guarantees that energy is used economically while ensuring that any alterations in the temperature or pressure of the supply don’t influence the hot-water output. The temperature can reach up to 140°F, and it is nearly 99.8% energy efficient. 

The EcoSmart ECO 27 operates with a 27 kW production rate and needs a 240V electrical supply with three 40 amp circuit breakers. It is certified for safety by both UL and CSA.

EcoSmart ECO 27 is great for consumers looking for a whole-house water heating system. It is easy to install, accessible on a budget, and great to use. In addition, it is a small, compact tankless electric water heater.

Reviews from customers


WDRM, a 30-year-old woman, was pleased with EcoSmart ECO 27. She said that “ EcoSmart ECO 27 is nice and compact. It does take a little bit longer for the hot water to reach my faucets, but when it does, it is unlimited and stays nice and hot. I can run 4 showers or baths, do a sink full of dishes after running a laundry load, and still have hot water.”

D. Dunn said that “EcoSmart ECO 27 worked like a charm. The heating process takes only 10 seconds as it quickly cranks up and starts heating the water flowing through it. The installation process is easy. And, the customer service is great to work with.”

3. EcoSmart ECO 11


  • 99% thermal energy efficient
  • Consistent hot water
  • 2 gallons capacity
  • ac_dc power source
  • Saves space



+ Comes with a convenient temperature adjustment knob
+ Excellent performance
+ Very small and powerful
+ Great customer service
+ Easy to install
+ Durable
– Design flaws

EcoSmart ECO 11 is perfect for people who live in compact modern homes. This affordable heater offers constant hot water for a shower and low-flow faucet simultaneously. It has a maximum of 3.1 GPM.

This electric tankless heater is one of the few models designed to the exacting UEF standard, and it boasts an impressive efficiency rating of 99.8%.

The ECO 11, like all the others in the EcoSmart range, is equipped with automated technology. According to the Dept of Energy, this technology can reduce annual hot-water expenses by about half.

The digital display of the EcoSmart ECO 11 permits users to set the temperature between 80°F and 140°F in intervals of 1°F. This 13 kW item requires a 220V voltage source and a single 60A circuit breaker.

The EcoSmart ECO 11 is a single-phase, 220V water heater with 11.8 kW power. This is more powerful than most other models. A 54A amperage draw requires a 69A breaker and a 6 AWG wire, and the pipe fittings must be ½” CF.

All EcoSmart products, such as the ECO 11, are equipped with Self-modulating technology. This technology is essential as it permits the unit to manage the energy it produces. This concept allows the manufacturing of hot water without an extra power supply requirement. The key benefit is that this item only utilizes water when necessary.

Reviews from customers


12-Volt Man, a resident from the USA, was happy with the purchase of the EcoSmart ECO 11. He said, “This model is for use in the colder north, so it’s 240V, not 120V. Accordingly, it needs heavier 240 breakers and 10/3-G feed cable to work right. Not hard to wire or plumb, but plan accordingly. The rotary temperature selector dial makes it easy to dial up the water temp on colder days and dial it down when it’s milder.” 

He further added that ”EcoSmart ECO 11 is an excellent addition to any shop or garage where you don’t want the hassle of installing a full-blown water heater. Just check the manufacturer’s site to ensure you get the correct unit for your location.”

J. Letzelter bought ”EcoSmart ECO 11 in September. He declared the installation process of the heater relatively easy. J. Letzelter lives in South Florida and found the incoming water from the heater quite warm. He said, “ The unit works great, the thermostat goes to 140 degrees, and the water temperature reaches 143 degrees when tested at the kitchen faucet. That being said, I keep the thermostat set at 104 degrees. If you need hotter water for any reason, it’s very easy to turn up the thermostat and then back down when you’re done.”

4. Rheem RTEX-18


  • External digital thermostatic control with LED display
  • Most advanced self-modulation
  • 4.4 GPM flow rate
  • 18 kilowatts capacity
  • AC/DC power source



+ Continuous hot water
+ Great water heater
+ Amazing design
+ Easy to install
+ Great quality
+ Good price
– Not durable

The Rheem RTEX-18 is a reliable, robust heater worth the cost. It is well-known for its strength and efficiency, lasting longer periods with minimal problems.

Rheem’s tankless heaters have a remarkable self-regulating technology that keeps the copper heating components at the designated water temperature. This technology also enables the heater to manage times of great demand by flow limitation.

People can access a range of flow rates, beginning at 2 gallons every minute and reaching up to 4.4 GPM under perfect conditions. It is sufficient to service a standard house and run two machines simultaneously.

Rheem provides a 5-year warranty for their heaters and ensures that the unit remains operational for a substantial time. Additionally, the enhanced digital user interface and LED display make it extremely easy to set up the heater.

Reviews from customers


Mike Dunn liked the Rheem RTEX-18 heater for his self-built new house. He said, “This is not the big tank that sits and keeps water hot all day and night. It only uses energy (electric in this case) when a hot water faucet turns on. This heater requires two 40-amp circuits. My house was only framed out, and it was easy to install electric requirements. This is easy to install if you are a handyman or high-level dIY’er.”

Jarod Dunn claimed that the Rheem RTEX-18 heater works very well for my 3 bed/2 bath 1400 sqft home. He said, “If you’re using this heater for a whole home unit, I recommend setting it at 140° or 135° but nothing lower. I tried 130°, and the two showers were hard to warm with straight hot going in both. At 140°, you can split hot/cold so both get fair amounts of hot water.”

He added, “One shower could get hot then cold several times before getting out. But after the first 4-7 days of usage, it leveled out, and a hot shower stays hot no matter how long or short it is.”

5. Stiebel Eltron Tempra 24 Plus


  • Maintains water temperature for constant comfort
  • Advanced Flow Control patented technology
  • Eco friendly unit saves energy
  • Small, sleek white design
  • Easy to operate
  • Needs hard wiring
  • 18000 watts



+ Great unit for colder weather
+ Beautifully designed heater
+ Stable hot water for hours
+ Very efficient heater
+ Affordable
– Quality needs improvements

The Stiebel Eltron Tempra is a highly effective electric tankless water heater with a maximum output of 7.5 GPM. It is capable of supplying enough water for four bathrooms operating at the same time.

This device can raise the temperature of the water to 140°F, much higher than the upper limit of 110°F (recommended by the U.S. Dept of Energy).

Although no system is flawless, the Stiebel Eltron is one of the most reliable options because its efficiency rate is nearly 99%.

Automated modulation helps to maintain steadiness in temperatures, and the unit operates without causing any noise. You can store the desired temperature in the memory with the help of the digital display.

This 36 kW model needs a 240V source and three 50 amp breakers. A wide range of Stiebel Eltron Tempra models provides exceptional solutions for all setups. The security of a product is certified by independent organizations such as UL and CSA.

Reviews from customers


Matthew K. was very impressed with the Stiebel Eltron Tempra 24 Plus. He said, “I have taken two showers at once and had the washing machine and dishwasher going. I noticed a pressure drop, but the water temps stayed pretty consistent and hot. And I love that I’m only using electricity when using the water, unlike my old tank water heater.”

Alex Armstrong claimed the Stiebel Eltron Tempra 24 Plus is a very efficient product. He said, “More efficient than prior electric water heaters I’ve owned at other properties. Without a doubt, the highest quality electric water heater I have ever owned too – and I’ve owned many.”

He further added, “The temperature control is outstanding. Raise and lower with precision. And regardless of flow or changes due to sudden requests for water from things like the washing machine or toilet, etc., the water always maintains the precise temperature.”

6. Thermomate


  • Instant unlimited hot water
  • Self-modulating technology
  • Stable water temperature
  • 208~240V hardwire power source
  • Saves 60% on water heating cost



+ Great point of use water heater
+ Excellent product
+ Exact water temp settings
+ Saves space and energy
+ Easy installation
– Minor issues

The Thermomate Tankless Water Heater offers excellent value for money that provides instantaneous hot water for up to three different uses.

The digital thermostat makes adjustments with single-degree precision and self-adjustment for a steady temperature, as well as the possibility of maximum energy efficiency.

Instead of submerging the heating elements in the water supply, they are located next to it, resulting in less scale and corrosion build-up, thereby prolonging its lifespan.

The unit has an overheating safeguard and a protection system in case of a water source interruption. Moreover, Electric Testing Laboratories have been approved for safety.

Thermomate offers budget-friendly electric tankless water heaters in two power options – 11 kW and 27 kW – enabling customers to save money while satisfying their hot-water requirements.

This 18 kW model requires a voltage of 240V and two 40A circuit breakers. Combining it with a gas heater could be a suitable way to produce hot water and heat in an underground space or garage.

Reviews from customers


Rickaboo considered the Thermomate heater a perfect point-of-use heater. He said, “I took a chance and bought this heater for a tiny house I built for myself. Granted, it’s only one other person and me. This heater keeps the water at the temp I set indefinitely. It takes a few seconds to get it there. It’s great to turn the dial and choose how hot or cool your shower will be.”

Richard M. claimed the Thermomate heater is excellent if installed correctly. He said, “I installed this in my hunting lodge to feed hot water to a bathroom. It sends hot water to a shower and sink and never misses a beat!! The water temp. in the mountains is 50 degrees F. and has no problem heating the water. I have it set to 120 degrees, and the water temperature is 120 on full heat. Make sure you use two 30A breakers and 10g. wire.”

7. Rheem RTEX-13


  • External adjustable digital thermostatic control with LED display
  • Durable Copper immersion two heating elements
  • Battery powered source
  • 99.8% energy efficient
  • 13 KW



+ Great solution for unlimited hot water
+ Great little tankless water heater
+ Ensure proper wiring for the required power
+ An excellent Rheem product
+ Small yet powerful
+ Easy to install
+ Space saver
+ Great price
– Uses too much power

Rheem RTEX-13 is a compact electric tankless water heater that controls water temperature from a panel built into the front of the unit. It also has a thermostat dial that adjusts temperature over nine settings.

The Rheem Tankless Electric RTEX 13 has a low water activation threshold of 0.3 gallons per minute. It can provide up to 4.8 gallons per minute of continuous hot water to two taps and a shower simultaneously.

The flow rate for this type of water heater, similar to other tankless models, is contingent upon the difference in temperature between the inlet of the cold water and the hot water produced by the unit.

Certain authorities have claimed that if you live in a location with frigid temperatures, the Rheem tankless water heater, as with other similar models, may not perform as well as it would in a warmer climate.

Reviews from customers


David Smith is quite happy with the purchase of Rheem RTEX-13. He said, “ My orchids love the slightly heated water! With this water heater being used to raise the water temperature to about 92 degrees, the plants have responded by growing and blooming more strongly with a much better overall appearance.”

Joshua W. Mandevill claimed Rheem RTEX-13 as a wonderful product! He said, “The plumbing was very easy, but you have to make certain that all the fittings are watertight as they are prone to leak easily if care is not taken to ensure they seal properly. The temperature setting is spot on, and I can turn the hot only on in the shower. It is the perfect temperature and easy to adjust with the spin knob and digital readout on the front of the unit.”

8. Stiebel Eltron DHC 3-1



  • 50% less power consumption compared to storage-type heaters
  • Hydraulically controlled for quiet operation
  • Resettable safety high-limit switch
  • Battery powered source
  • Instant hot water
  • 3000 watts



+ Great for low flow-on-demand heating requirements
+ Provides hot water on demand
+ Easy to install
– Minor issues

The Stiebel Eltron DHC 3-1 is an ideal 120 low-volt system for confined areas. It has a cost-efficient price tag compared to other similar units and operates as promised.

The Stiebel Eltron DHC series tankless water heaters are cost-effective, small in size, beautiful in appearance, and constructed with quality in mind for basic requirements like restroom sinks, kitchens, corporate restrooms, emergency eye wash fountains, and so on. The DHC range is most suitable for a steady flow rate.

The Stiebel Eltron DHC 3-1 is highly compact, allowing it to be easily installed beneath a sink, in a cupboard, or even in a closet. This then ensures hot water is quickly and conveniently accessible when needed.

Placing the heater close to the area where it will be used can prevent the heat from being lost through lengthy piping.

If the DHC 3-1 is sufficient enough to provide the necessary hot water for the room in new constructions, then it will spare the need to run a hot water pipeline from the primary central water heater, resulting in considerable savings in plumbing and materials cost.

Reviews from customers


James considered Stiebel Eltron DHC great for low flow-on-demand heating requirements. He said, “I use this in my cabin on each of the sinks, and it heats within a few seconds and stays hot.”

David Mark Williams considered Stiebel Eltron DHC as an efficient under-sink heater. He said, “This was installed on the hot water supply line under a kitchen sink, as it typically takes 2 1/2 gallons of water before hot water begins to flow. I connected it to the same circuit that powered my previous trash compactor. It is simple to install.”

Best Electric Tankless Water Heater: Installation


Most DIY enthusiasts would suggest that setting up an electric tankless water heating system is straightforward.

If you lack the necessary knowledge, it is not advisable to attempt the task yourself just to cut costs. Such an act is too hazardous, and the potential losses are not worth taking the risk. For certain water heaters, a certified specialist must have them installed, or else the guarantee will be canceled.

It’s necessary to remember that not all properties can accommodate a POE unit due to its high amp draw. This could signify that your previous electrical service panel requires wires and breakers of a larger size or that you need to install an entirely fresh one, which would cost approximately two thousand dollars in electrical labor.

Best Electric Tankless Water Heater: Maintenance

If you do proper maintenance, electric tankless water heaters last longer than regular storage tank heaters. It can last up to 15-25 years if you delime regularly.

The delimiting process involves removing any limescale deposits that adhere to copper or stainless steel heating components when they are employed to heat water with high mineral content. 

An alternate solution would be to set up a water softener ahead of the hot water tank. A guarantee for a product’s lifetime can give one comfort and assurance.

FAQs (Frequently Asked Questions): The Best Electric Tankless Water Heater

1. What is the downside of an electric tankless water heater?

An electric tankless water heater can heat surplus water at a time. If you need more hot water than the system can produce, such as when running the dishwasher, washing machine, and shower at the same period, the temperature of the water will become unsteady due to the heater attempting to supply for all three spots at the same time.

2. Are electric tankless heaters any good?

Electric tankless heaters are the most efficient choice for residential, commercial & industrial uses. According to the Dept of Energy, heating with hot water is the second most expensive energy expense, so it’s a great area to focus on if you want to increase energy efficiency.

3. Which electric tankless water heater has the best warranty?

Stiebel Eltron Tempra 36 Plus has a 7-year warranty against leakage and a 3-year warranty against workmanship and material defects.

4. What is the most common problems with tankless water heaters?

Here are the common problems with tankless water heaters: 

  • Too hot water
  • Too noisy unit
  • The burner doesn’t ignite
  • Low water pressure
  • Water temperature fluctuation.

Summary: Best Electric Tankless Water Heater


If you’re looking for a reliable, energy-efficient, and cost-effective way to heat your home water, an electric tankless water heater should be your top choice.

These devices provide hot water in response to your hot water needs and automatically replenish the tank with hot water stored in the tank.

The best electric tankless water heater has many possible features that can make your water heating experience even more convenient. While some models are better suited to certain uses than others, you can rest assured that you will find the perfect solution for your home’s needs.

I hope this article on the best electric tankless water heater sounds helpful!

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