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10 Best Electric Tankless Water Heater 2025 in the United States

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Our technology thoroughly searches through the online shopping world, reviewing hundreds of sites. We then process and analyze this information, updating in real-time to bring you the latest top-rated products. This way, you always get the best and most current options available.

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Our Top Picks

#1

Winner

Stiebel Eltron 239223 Tankless Water Heater – Tempra 29 Plus – Electric, On Demand Hot Water, Eco, White, 23

Rating
9.9
Chosen by1,379
Flow Rate
Power Rating
Temperature Rise

Most important from
2063 reviews

Flow Rate
The unit's performance exceeds expectations with its convenience and efficiency, providing a continuous flow of hot water even when running two showers simultaneously.
Power Rating
Installation may require significant electrical work, such as adding a subpanel, but the unit performs flawlessly once set up.
Temperature Rise
Precise temperature control ensures hot water is delivered exactly as desired without any fuss.
Energy Efficiency
The tankless system is eco-friendly and cost-effective, only using hot water when necessary.
Size and Installation Requirements
Its space-saving design and minimal noise are standout features, especially for installations near living spaces.

The Stiebel Eltron 239223 Tempra 29 Plus is a high-performing electric tankless water heater that provides an on-demand and continuous supply of hot water. It features a sleek, space-saving design and does not require venting, which makes it versatile for various home installations. This model has a maximum flow rate of 3 gallons per minute (GPM), making it suitable for households with moderate hot water needs.

Its power rating is substantial, operating at 28.8 kW, which ensures a quick temperature rise but also means it requires a significant electrical setup: 240-volt service, three dedicated 40 amp breakers, and at least 200 amp total service to the home. This could be a hurdle for some installations and might require professional electrical work to update the home's capacity.

The unit features two temperature memory presets, providing convenience for users with different hot water preferences. It also has a useful LED display for easy monitoring and adjustments. Energy efficiency is a highlight, as tankless systems generally save on energy compared to traditional tank heaters by only heating water as needed. Potential buyers should consider the installation requirements carefully. This unit is most beneficial for medium to large households that can support the electrical demands, and who are looking for a reliable, space-saving, and energy-efficient solution for their hot water needs.

Rating
9.9
Chosen by1,379
Flow Rate
Power Rating
Temperature Rise

Most important from
2063 reviews

Flow Rate
The unit's performance exceeds expectations with its convenience and efficiency, providing a continuous flow of hot water even when running two showers simultaneously.
Power Rating
Installation may require significant electrical work, such as adding a subpanel, but the unit performs flawlessly once set up.
Temperature Rise
Precise temperature control ensures hot water is delivered exactly as desired without any fuss.
Energy Efficiency
The tankless system is eco-friendly and cost-effective, only using hot water when necessary.
Size and Installation Requirements
Its space-saving design and minimal noise are standout features, especially for installations near living spaces.
#2

Stiebel Eltron Tankless Water Heater – Tempra 24 Plus – Electric, On Demand Hot Water, Eco, White, 20.2

Rating
9.8
Flow Rate
Temperature Rise
Size and Installation Requirements

Most important from
2063 reviews

Flow Rate
The ability to provide a continuous flow of hot water, even when running two showers simultaneously, is remarkable.
Temperature Rise
Accurate temperature control ensures you get the hot water you desire without any fuss.
Size and Installation Requirements
Installation is flexible, as the unit requires no flue and can be placed anywhere.

The Stiebel Eltron Tankless Water Heater - Tempra 24 Plus is a solid choice for anyone looking for an electric water heater that offers on-demand hot water. One of its standout features is the continuous flow technology that ensures a consistent water temperature, making it ideal for families who need uninterrupted hot water during showers or other tasks. With its compact design, this unit saves space, and since it doesn’t require venting, installation is generally straightforward, which can be a major plus for homeowners.

Energy efficiency is another strong point, as it utilizes auto-modulation to control water flow and reduce energy consumption. The included savings monitor is a nice touch, helping you track energy savings over time. Additionally, the digital temperature display and preset options enhance usability, making it easy to adjust settings to your preference. The safety feature allowing you to limit the maximum temperature is a thoughtful addition, particularly for homes with young children.

On the downside, you need to ensure your electrical system can support this unit, as it requires a minimum service of 150 amps, which may necessitate an upgrade for some homes. While it performs well within its capacity, it’s important to note that the flow rate may decrease if multiple outlets demand hot water simultaneously, so larger households with high simultaneous usage might experience some limitations. The warranty offered provides peace of mind, covering leakage for seven years and parts for three years, indicating the manufacturer’s confidence in the product’s durability. Potential buyers should consider whether the installation costs and electrical requirements align with their home setup. The Tempra 24 Plus is a reliable, energy-efficient option for those who need a steady supply of hot water and have compatible electrical infrastructure.

Rating
9.8
Flow Rate
Temperature Rise
Size and Installation Requirements

Most important from
2063 reviews

Flow Rate
The ability to provide a continuous flow of hot water, even when running two showers simultaneously, is remarkable.
Temperature Rise
Accurate temperature control ensures you get the hot water you desire without any fuss.
Size and Installation Requirements
Installation is flexible, as the unit requires no flue and can be placed anywhere.
#3

Rheem 18kW 240V Tankless Electric Water Heater, Gray

Rating
9.5
Power Rating
Temperature Rise
Size and Installation Requirements

Most important from
1938 reviews

Power Rating
Cheaper than Home Depot and pulls about 8kw upon use.
Temperature Rise
Biggest adjustment is that it gets warmer before getting hot in the shower; either let it run longer or adjust while showering.
Size and Installation Requirements
Great product, works wonderfully in a tiny house.

The Rheem 18kW 240V Tankless Electric Water Heater is a solid choice for those looking for an efficient and space-saving water heating solution. One of its standout features is the impressive flow rate of up to 4.4 gallons per minute (GPM), which makes it suitable for smaller households or apartments where demand for hot water isn't excessively high. Its energy efficiency rating of 99.8% is quite remarkable, meaning you'll likely save on your energy bills compared to traditional tank heaters. The self-modulation technology adjusts the power based on hot water demand, which further optimizes energy use.

The external digital control with an LED display is user-friendly, allowing for precise temperature settings within a +/- 1-degree accuracy. This feature is particularly beneficial for those who want to maintain consistent hot water temperatures. The installation is straightforward as well, with bottom connections that make it easier to replace or service when needed.

There are a few drawbacks to consider. While the 4.4 GPM flow rate is adequate for smaller setups, larger families or homes with multiple bathrooms may find it insufficient during peak usage times. Additionally, being an electric unit, it may not be the best option for locations where electricity supply is unreliable or insufficient to support its high wattage of 18,000 watts. Lastly, while the unit is compact, its installation does require adequate space and professional help, especially for wall mounting, which could be a consideration for DIY enthusiasts.

Rating
9.5
Power Rating
Temperature Rise
Size and Installation Requirements

Most important from
1938 reviews

Power Rating
Cheaper than Home Depot and pulls about 8kw upon use.
Temperature Rise
Biggest adjustment is that it gets warmer before getting hot in the shower; either let it run longer or adjust while showering.
Size and Installation Requirements
Great product, works wonderfully in a tiny house.

Buying Guide for the Best Electric Tankless Water Heater

Choosing the right electric tankless water heater can significantly impact your comfort and energy efficiency at home. These devices heat water on demand, which means you won't run out of hot water and you can save on energy costs since there's no need to keep a large tank of water hot at all times. However, selecting the right model involves understanding several key specifications to ensure it meets your household's needs.
Flow RateFlow rate, measured in gallons per minute (GPM), indicates how much hot water the heater can produce at a time. This is crucial because it determines whether the heater can supply enough hot water for your household's simultaneous needs, such as running a shower and a dishwasher at the same time. For small households or single applications, a lower GPM (around 2-4 GPM) might suffice. Larger households or those with higher simultaneous hot water demands should look for higher GPM ratings (5 GPM and above). Assess your household's peak hot water usage to determine the appropriate flow rate.
Power RatingThe power rating, measured in kilowatts (kW), indicates the heater's capacity to heat water. Higher kW ratings mean the heater can heat water more quickly and to higher temperatures. This is important for ensuring that the water reaches the desired temperature, especially in colder climates where incoming water temperature is lower. For warmer climates or lower hot water demands, a unit with a lower kW rating (around 10-15 kW) may be sufficient. In colder climates or for higher demands, look for units with higher kW ratings (18 kW and above). Consider your climate and hot water needs to choose the right power rating.
Temperature RiseTemperature rise refers to the increase in water temperature that the heater can achieve. This is important because it affects how hot the water will be when it reaches your tap. The required temperature rise depends on the incoming water temperature and the desired output temperature. For example, if your incoming water is 50°F and you want it to be 120°F, you need a temperature rise of 70°F. Units with higher temperature rise capabilities are better suited for colder climates or higher hot water demands. Determine your incoming water temperature and desired output temperature to select a heater with the appropriate temperature rise.
Energy EfficiencyEnergy efficiency, often expressed as a percentage, indicates how effectively the heater converts electrical energy into hot water. Higher efficiency ratings mean less energy waste and lower operating costs. This is important for reducing your energy bills and environmental impact. Most electric tankless water heaters have high efficiency ratings (around 90-99%), but even small differences can add up over time. Look for units with higher efficiency ratings to maximize energy savings. Consider your long-term energy costs and environmental goals when evaluating efficiency.
Size and Installation RequirementsThe physical size of the heater and its installation requirements are important for ensuring it fits in your available space and can be installed properly. This includes considerations like electrical requirements, ventilation, and mounting options. Smaller units are easier to install in tight spaces but may have lower capacities. Larger units require more space and may need professional installation. Assess your available space and installation capabilities to choose a unit that fits your home and can be installed safely and efficiently.

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