The 7 Best Electric Tankless Water Heaters — Reviewed and Ranked (2024)

Updated on:
January 6, 2024

For many people, electric tankless water heaters are the ideal type of water heater. They enable rapid hot water heating at the point of use (POU) or point of entry (POE), reduce energy costs compared with gas-powered options, and provide excellent flow rates that satisfy the demands of the vast majority of homes in the US.

The best electric tankless water heater is one that provides a high flow rate, better energy-cost savings, increased durability, several safety certifications, and an appealing warranty.

I have researched and rated the seven best electric tankless water heaters on the market to help you make the best choice for your home.

Here are my findings.

1. Stiebel Eltron Tempra 36 Plus — 9/10 (Best electric tankless water heater overall)

Tempra electric tankless water heaters from the reputable German manufacturer Stiebel Eltron are compact but strong enough to provide hot water to multiple fixtures and locations in any season or environment. The Tempra 36 Plus is their most advanced model and also the best electric tankless water heater I’ve reviewed to date. 


The Tempra 36 Plus is the largest in the Tempra series of electric tankless water heaters that includes the Tempra 12, 15, 20, 24, and 29 Plus. These numbers represent the models’ power output in kilowatts (kW). In this case, the Tempra 36 Plus has a maximum power output of 36 kW. 

Intended as a substitute for a 60-gallon electric tank style water heater, this $812.35 tankless electric water heater is built to last. The heat exchangers are made of solid copper, while the fittings are made of brass. Unlike other electric tankless water heaters, this unit’s heating elements will never need to be changed thanks to a secondary thermal cut-out switch. 

The innovative technologies incorporated into this electric water heater are the main reasons I chose it as the best of its kind. 

To start with, every Tempra model incorporates the patented Advanced Flow Technology. To prevent the water heater from being overworked, Advanced Flow Control will automatically adjust the cold water flow rate. The Tempra 36 Plus automatically provides less water, but at the specified hot water temperature, as opposed to water heaters from other manufacturers that may provide water that is too cold to be used.

Some other interesting features include:

  • Self-modulating technology, a function distinct from the Advanced Water Flow Control, will gauge the temperature of the incoming water and adjust the heater accordingly.
  • A digital thermostat precisely regulates the temperature. The digital display on the Tempra 36 Plus enables you to set and monitor the temperature, which ranges from 68 to 140 degrees Fahrenheit. It also allows for user customization and the display of useful information, such as water flow, wattage, fault codes, energy saving data, and more.
  • Smart microprocessor technology and several temperature and water-flow sensors work together to regulate water flow and temperature.
  • Operation is silent, as there are no moving mechanical components.
  • The Tempra 36 Plus can provide hot water to up to four fixtures simultaneously. It has a maximum flow rate of 8 GPM (gallons per minute).
  • A self-diagnostic system helps with troubleshooting by alerting the user when a problem has occurred.
  • The small and compact size offers significant space savings.
  • There is a seven-year warranty against leakage and a three-year warranty against workmanship and material defects.
  • The Tempra 36 Plus has a low activation flow rate of 0.77 GPM (gallons per minute).


Despite all the high-tech benefits associated with the Tempra 36 Plus electric tankless water heater, a couple of drawbacks deserve to be mentioned. 

This Stiebel tankless water heater needs a 3×60 amp circuit breaker, which takes a substantial amount of panel space. To support the Tempra 36, your electrical panel must be upgraded. Even though the manufacturer claims that the fluctuation of hot water is low, some customers have claimed that the “cold-water sandwich” effect is still present, particularly when two fixtures are in use simultaneously.


The Stiebel Eltron Tempra 36 Plus Tankless Electric Water Heater is the best electric tankless water heater available at a reasonable price that offers the best value. It is crammed full of unique characteristics that make it the best energy heater for low-flow applications. Its sleek, compact design allows it to fit behind a staircase closet, a fireplace, beneath a sink, or in any other small spot within the house.

It has low energy consumption and is equipped with sophisticated control systems that enable you to monitor and modify temperature and water flow. 

If you need an energy-efficient and reliable electric tankless water heater, visit the Stiebel Eltron website today.

2. EcoSmart ECO 27 Electric Tankless Water Heater — 8.7/10 (Best warranty)

The ECO 27 is the newest model in EcoSmart’s popular range of electric tankless water heaters, the ECO series. This water heater has the most appealing warranty compared with other electric water heaters on this list.


In sunnier climes, the ECO 27 electric tankless water heater can provide a single-family house with steady, unlimited hot water at 6.6 GPM, more than enough for two showers and an extra fixture running at around 2 GPM. This makes it suitable for condos, apartments, and townhouses. Even at the lowest groundwater temperatures, the ECO 27 can heat almost 3 gallons of water per minute. That would be adequate to simultaneously operate two showers emitting no more than 1.5 GPM each in the northern regions of the United States.

The Ecosmart Eco 27’s energy-efficient, self-modulating heat sensor keeps the inline electric water heater operating at the optimal energy level. For example, if there is a large demand for water, most electric tankless water heaters will simply provide less hot water since they cannot keep up. The Ecosmart Eco 27 will regulate the water flow so that you always get the ideal temperature.

Here is a comprehensive list of features included in this electric tankless water heater:

  • A consistent hot water supply never runs out. Constantly monitored water temperature and regulated flow rates ensure consistent performance within one degree of the specified temperature.
  • The ECO 27 has stainless steel and copper components for increased longevity and efficiency.
  • This electric tankless water heater has a flow rate of 6.6 GPM at an inlet temperature of 74°F. This is enough to supply hot water to four fixtures in your home.
  • At 17″ x 17″ x 3.75″ the ECO 27 is small enough to fit even in the tightest space within the house. It’s a great choice for condominiums and apartments.
  • Self-modulating technology automatically modifies the flow rate to keep up with demand.
  • The ECO 27 features a 27kW power output that is divided into three 9kW heating chambers, allowing the water heater to only consume the amount of energy required to heat the water. EcoSmart claims that its water heaters can reduce your water heating costs by up to 50% as a result of this technology.
  • The EcoSmart ECO 27’s heat exchangers, electrical components, and heating elements are covered by an exceptional limited lifetime warranty. No other manufacturer on this list provides this type of warranty.
  • At $479, the ECO 17 is one of the most affordable electric tankless water heaters on the market.


During my assessment of the EcoSmart ECO27 tankless electric water heater, I discovered a few flaws. 

Despite the manufacturer’s assurances of the copper components’ longevity, there have been multiple instances of heaters malfunctioning owing to severe corrosion of the copper elements. 

The lifetime warranty is only valid if the water heater is installed by a licensed plumber and if you register the item within 30 days of purchase on the manufacturer’s website.

Their customer support is also not as responsive as I expected. There are reports of customers being left on the line for hours, and others complain of long-winded arguments with support staff.


If you require an electric tankless water heater for your whole home, the EcoSmart ECO 27 is energy efficient and has a simple digital thermostat for accurate temperature control. It can serve a single-family household and comes in a compact package, making it perfect for individuals with limited space. Additionally, the warranty is outstanding, so long as you remember to have a professional install the EcoSmart ECO 27 water heater.

3. Rheem RTEX 13 — 7.6/10 (Cheapest electric tankless water heater)

The Rheem RTEX 13 electric tankless water heater is the newest addition to the Rheem series of highly renowned electric tankless water heaters.


The Rheem RTEX 13 is mainly intended for point-of-use (POU) applications. This electric tankless water heater is designed for single-shower installations and has a maximum hot water output of four gallons per minute. A front-mounted adjustment dial allows you to alter the water temperature as desired. The presence of a digital temperature control on the RTEX 13’s front panel indicates whether the device is active or in standby mode.

Water heaters may sometimes be the cause of a large annual power bill. Fortunately, this electric tankless water heater is quite efficient in conserving energy. This model is 99.8% energy efficient! The RTEX 13 has 13 kW of power. It requires a 60A/240V circuit breaker and utilizes 6 AWG (American Wire Gauge) wire. In the long term, you will save a substantial amount of power by just using the heater while the water faucet is running.

Here is a list of features that are incorporated into the RTEX 13:

  • This unit provides an on-demand, steady flow of hot water.
  • The digital temperature control allows for precise temperature regulation (in 1° increments) from 80 to 140 degrees Fahrenheit.
  • Immersion heating components are made of sturdy copper with a brass top that is threaded for quick repair and increased longevity.
  • This unit has a maximum 4.8 GPM flow rate. 
  • The RTEX 13 needs a minimum amount of water flow (0.4 GPM) to activate.
  • The unit costs around $280, which is quite affordable compared with other electric tankless water heaters on this list.
  • The RTEX 13 has a five-year heating chamber and a one-year parts limited warranty.


Rheem sells the RTEX 13 as a whole-house solution for heating water. However, this tankless water heater is really only suitable for single use or POU (point-of-use) applications. It can’t supply hot water to three fixtures simultaneously, especially if your home is located in a cold area. You’ll need to upgrade to other larger and more expensive models in the RTEX series.

The copper elements need to be maintained or replaced frequently to increase the longevity of the water heater.


The Rheem RTEX 13 electric tankless water heater seems to be an economical and reliable purchase. Numerous online critics have awarded it four or more stars. This unit is not ideal for colder areas due to the variables that limit the RTEX 13’s capacity to heat water and its flow rate, although quality control challenges may be mitigated with extra care. When installed by a certified expert and used in accordance with the manufacturer’s instructions, the RTEX 13 can be one of the best investments you’ve ever made.

To learn more about this tankless water heater, click here.

4. Eemax Home Advantage II 36kW Electric Tankless Water Heater

The new addition to the line of Eemax electric tankless water heaters is the 36-kilowatt Eemax HomeAdvantage II. This $850 unit supplies a consistent supply of hot water to your entire home. It achieves an impressive 99.8% efficiency (selectable from 80 to 140 degrees F) thanks to self-modulating technology and computerized temperature-management controls. With the HomeAdvantage II, you can cut down on your utility bills, water use, and space, all while saving money. As the name implies, the Eemax Home Advantage II 36kW is a great choice for your home.

This device is equipped with a thermo-optical sensor and a predictive control algorithm for effective heat management. The thermostatic control can respond to fluctuating temperatures while maintaining a constant hot water supply. The Eemax Home Advantage II has a maximum flow rate of 8.7 GPM at 77°F. 

However, there is something about this electric tankless water heater that I can’t seem to wrap my mind around. 

You see, Eemax is a large company, so large that it acquired the EcoSmart brand in 2013. That means that all EcoSmart products are made under the watchful eye of Eemax. Thus, I don’t understand how the EcoSmart ECO series of electric tankless water heaters can have a lifetime warranty while the top-of-the-line Eemax Home Advantage II gets a one-year limited warranty.

5. Titan N-270 (27kW) Electric Tankless Water Heater

Titan is a US-based manufacturer of some of the most prolific electric tankless water heaters on the market. The Titan SCR4 N-270 is currently their most powerful model.

The N-270 weighs 12 pounds and is 11.5 x 10.5 x 3 inches, so it does not need much space. This unit is intended to replace a conventional tank water heater while continuing to serve your house with an unending supply of hot water, which it does on demand, so no energy is lost.

The Titan N-270’s brass shell and dual Incoloy and nichrome components contribute to its longevity. This gadget fits a common 1/2-inch pipe, making it appropriate for most home configurations, and its 240V system can heat enough water for the whole family.

Other features include a manually resettable thermostat, a dual micro-temperature sensor for safety, two visible LED indicators (green for standby and red for on), 27kW output, and a 15-year guaranteed lifespan.

Most users are delighted with the simplicity of installation, which is an additional advantage. Titan will supply you with a thorough step-by-step instruction manual that allows you to complete the project without extensive plumbing or electrical experience. 

However, some disadvantages need to be mentioned. 

Compared with the EcoSmart ECO 27, which is its primary competitor, the Titan N-270 has a lower flow rate. It can deliver a maximum of 5 GPM at 36°F. That’s 1.6 GPM less than the ECO 27. This unit also doesn’t come with a lifetime warranty. However, they do provide a ten-year warranty on the casing and one-year on components.

The Titan SCR4 N-270 costs around $550, which is $71 more than the ECO 27.

6. Bosch Tronic 3000t ES2.5 Mini Tank Electric Heater

Not your typical electric tankless water heater, the Bosch Tronic 3000t ES2.5 is an honorable mention. It has a small 2.5-gallon water tank that provides an adequate hot water supply to a point-of-use (POU) fixture, such as a shower, kitchen sink, or faucet.

This mini tank electric water heater can be used in a number of ways. It can produce sufficient hot water for a single sink. You may also use it to complement an existing water heater that is placed some distance away from the location where hot water is required. This offers instant access to hot water.

Additionally, it may be installed in-line with a tankless water heater, which generally encounters intermittent “cold water sandwiching.” Thanks to this mini tank water heater, you do not have to wait more than a minute and a half for hot water to flow through your faucet.

Bosch offers a limited warranty of six years on the unit and two years on components.

To learn more about this electric hot water heater, visit the Bosch website today.

7. Camplux TE27 Electric Tankless Water Heater

Camplux is known for making outdoor-oriented portable appliances, such as griddles, stoves, firepits, and battery-powered water heaters. However, they recently started manufacturing residential water heaters and the TE27 electric tankless water heater is one of their best.

This fast electric tankless water heater has certifications from NFS (Nationally Recognized Testing Laboratories) and ETL (Edison Testing Laboratories) as well as safety against overheating. When the temperature is too high, the water heater will automatically shut off to prevent scalding injuries.

The Camplux TE27 has a maximum flow rate of 6.5 GPM at 77°F, a touchpad-controlled digital thermostat with an LCD display, and a smart remote controller. The unit can be mounted at any angle, and it has a pressure relief valve that drains the water during cold weather to avoid freezing the heater’s components.

However, despite all the glowing attributes, this electric tankless water heater has a slew of problems.

Users have complained about the TE27’s poor reliability. For instance, the water temperature doesn’t stick to the specified limit, instead regularly fluctuating from cold to warm but never hot.

This unit also requires a lot of water pressure to activate. This means that you have to turn the faucet on full blast if you need hot water, which wastes a lot of water. There have been reports of circuit breakers tripping, lights dimming, and electric appliances failing when this water heater activates.

Lastly, their customer support is unresponsive and they only provide a year of warranty, which is abysmal given the multiple defects associated with this brand.

Even though the Camplux TE27 electric tankless water heater costs around $399, I could not recommend it to anyone. Not until the defects are fixed.

The Bottom Line

After months of reviewing tankless electric water heaters, the Stiebel Eltron Tempra 36 Plus emerged as the best tankless water heater for electric homes that money can buy. Built to replace 60-gallon traditional water heaters, the Tempra 36 Plus can provide a continuous hot water supply to your entire house. 

Some of its distinct features include self-modulating technology, which measures the water temperature and adjusts the heater accordingly, Advanced Flow Control, which makes sure your water temperature remains steady even when there is fluctuation in the flow rate, a maximum flow rate of 8 GPM (gallons per minute), and a digital thermostat with a display that enables customizable settings on the unit.

With a combined warranty of 10 years and a retail price of $812.35, the Stiebel Eltron Tempra 36 Plus is the most reliable, most advanced, and most affordable 36kW electric tankless water heater available on the market today.

Best Electric Tankless Water Heaters Review Methodology

Here’s how I arrived at my findings.

Step 1: A big list of every electric tankless water heater available

To begin my investigation, I compiled a list of every electric tankless water heater currently available on the market. This encompasses all models with varying power outputs between 13kW and 36kW. I discovered that there are companies (such as Eemax and Rheem) with more than two product lines of the same kind competing in the market. This first stage helped me recognize the products offered by each manufacturer.

Step 2: Online reviews

I went online with my list of electric tankless water heaters to see what consumers had to say about each product. This necessitated hours of research on websites such as Consumer Affairs, Amazon, Lowes, Walmart, and the Better Business Bureau. I was ultimately able to determine which manufacturers produced the most dependable tankless electric water heaters and which models were most popular among customers.

Step 3: Product analysis

This is when I got down to the nitty-gritty of the issue at hand. I compiled the following list of all the essential qualities I would anticipate from a tankless electric water heater, including the distinctions between various kinds of tankless heaters:

  • How do tankless electric water heaters differ from gas tankless water heaters?
  • What advantages does an electric tankless water heater have over a gas tankless water heater?
  • What is the efficiency rating of electric tankless water heaters over tanked water heaters?
  • How much hot water is supplied by whole house/POU (point-of-entry) water heaters compared with POU (point-of-use) water heaters?
  • Are there any intuitive technologies incorporated into these units that improve their energy efficiency?
  • What are the costs of the different electric tankless water heaters on the market?
  • What household size does each water heater support?
  • Are there any accessories available with every purchase?
  • How long does each manufacturer’s warranty last?

This questionnaire was administered to every unit on my list. Any water heater that did not adequately meet my rigorous assessment criteria was eliminated from being considered the best tankless water heater out there.

Step 4: Interviews with real customers

With the remaining list of reliable tankless electric water heaters in hand, it was time to identify actual customers and inquire about their experiences. So, with the help of a few friends, I planned a door-to-door tour of every residence within a 10-mile radius. It was a lengthy and laborious process, but I was able to remove a couple more manufacturers from my list with the knowledge I gained.

Step 5: Interviews with manufacturers

This step includes contacting the marketing and customer service departments of the remaining manufacturers of tankless electric water heaters to demand replies to some of the negative customer feedback they have received. This enabled me to comprehend how each company reacted to criticism and how they interacted with consumers.

Step 6: Test drives

Next, I asked the manufacturers to send me some units to try out. I wasn’t sure what they would say, but I thought it was worth a shot. Surprisingly, more than 10 companies responded! So I rented a warehouse, brought in two water bowsers, and started putting each brand of water heater through a rigorous test drive.

Step 7: Ratings

Now that I knew about the various brands of hot water heaters, it was time to compare them. I rated each water heater based on whether it had any of the following features:

  • A lengthy warranty period
  • A high flow-rate of hot water
  • Affordability and availability
  • Energy efficiency ratings 
  • Technology incorporated in the heating elements to avoid corrosion
  • A reasonable amount of heat required for each tankless unit to operate at full capacity
  • Respectable annual energy savings
  • Distinguishing features (such as wireless remote control, dry fire protection, or leakage protection)

Best Electric Hot Water Heater

After months of rigorous research, I finally had an answer. The Stiebel Electric Tempra 36 Plus is the best electric tankless water heater you can get for your home.

The 36kW Stiebel Eltron Tempra 36 Plus is a tankless water heater that modulates itself. It may be used to heat water for the entire household.

If you reside in a region where the groundwater temperature is around 42°F, you can anticipate a flow rate of 3.9 GPM. However, this will grow to 4.6 GPM if your location is 52°F and to 8 GPM if your area is 72°F. 

The Tempra 36 Plus offers microprocessor-controlled temperature management as well as a digital temperature display and dial selection, allowing you to adjust the appropriate output water temperature between 86°F and 140°F. It is one of the few tankless electric water heaters that can adjust its output power according to the temperature and flow rate of the water it is heating.

At full capacity, this unit can supply water to up to four showers and a faucet simultaneously.

Stiebel Eltron’s proprietary Advanced Flow Control technology is integrated into the Tempra 36 Plus. When the unit’s sensors determine that the flow demand is greater than the heater’s capacity, the flow rate is automatically adjusted. The ability to meet occasionally high flow demands is especially beneficial in cold locations and other situations where a larger model would be impractical due to limited power supply.

On top of it all, the Stiebel Eltron Tempra 36 Plus comes with a seven-year leakage warranty and a three-year parts warranty.

If you are in the market for a water heating solution for your home or would like to upgrade your current water heater, the Stiebel Eltron Tempra 36 Plus is an excellent choice.

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