We Use CookiesWe use cookies to enhance the security, performance, functionality and for analytical and promotional activities. By continuing to browse this site you are agreeing to our privacy policy

10 Best Electric Tankless Hot Water Heater 2025 in the United States

How do we rank products for you?

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.

headphones-stars

Our Top Picks

#1

Winner

Stiebel Eltron Tankless Water Heater - Tempra 29 Trend – Electric, On Demand Hot Water, Eco, White

Rating
10.0
Chosen by1,126
Flow Rate
Temperature Rise
Power Requirements

Most important from
2065 reviews

Flow Rate
It delivers a continuous flow of hot water, even when running two showers simultaneously, ensuring no interruptions.
Temperature Rise
Temperature control is precise, providing the desired hot water without any hassle.
Power Requirements
The water heater uses only the necessary amount of power, making it both eco-friendly and cost-effective.
Size and Installation
The installation process is smooth and the device is impressively quiet, making it perfect for installation near living spaces.

The Stiebel Eltron Tempra 29 Trend is an electric tankless water heater designed for those seeking a continuous supply of hot water. One of its standout features is the ability to provide on-demand hot water, which means no more unexpected cold showers. With a flow rate of up to 9.5 gallons per minute, it can serve an entire household, making it ideal for families or homes with high water usage needs.

In terms of energy efficiency, this unit is a strong contender. Its sleek design not only saves space but also incorporates auto-modulation technology to minimize energy use when hot water is not needed. This makes it a great eco-friendly choice for environmentally conscious consumers. The silent operation further enhances its appeal, as it won't disrupt your home environment while in use.

The Tempra 29 Trend requires a significant electrical service of at least 200 amps, which may necessitate an upgrade to your home’s electrical system if it currently does not meet this requirement. Additionally, while it has a good warranty (7 years for leakage and 3 years for parts), some users may still worry about the initial installation costs and the need for professional setup. The digital temperature display is a convenient feature, allowing users to monitor their water temperature easily. It's compact at 16.63 inches wide and 14.5 inches high, making it suitable for various installation spaces. Potential buyers should verify that their plumbing can support a tankless unit effectively. The Stiebel Eltron Tempra 29 Trend serves as an excellent choice for those looking for reliable, efficient hot water solutions, particularly in larger households, while being mindful of the electrical demands and installation considerations that come with such a high-performance unit.

Rating
10.0
Chosen by1,126
Flow Rate
Temperature Rise
Power Requirements

Most important from
2065 reviews

Flow Rate
It delivers a continuous flow of hot water, even when running two showers simultaneously, ensuring no interruptions.
Temperature Rise
Temperature control is precise, providing the desired hot water without any hassle.
Power Requirements
The water heater uses only the necessary amount of power, making it both eco-friendly and cost-effective.
Size and Installation
The installation process is smooth and the device is impressively quiet, making it perfect for installation near living spaces.
#2

Rheem 18kW 240V Tankless Electric Water Heater, Gray

Rating
10.0
Temperature Rise
Power Requirements
Size and Installation

Most important from
1947 reviews

Temperature Rise
You may feel the need to set the temp to 145 if converting from a traditional water heater tank, but it's unnecessary unless using multiple hot water devices simultaneously.
Power Requirements
Cheaper than Home Depot and pulls about 8kW upon use.
Size and Installation
Installed in a tiny house and works wonderfully.

The Rheem 18kW 240V Tankless Electric Water Heater is designed to offer an on-demand hot water solution for homeowners looking to save space and energy. With a flow rate of up to 4.4 gallons per minute (GPM), it can efficiently supply hot water for multiple outlets at once, making it suitable for medium-sized households or apartments. One standout feature is its external digital thermostatic control with a precise +/- 1 degree accuracy, allowing users to easily set their desired water temperature.

The self-modulation technology adjusts the power based on your hot water needs, optimizing energy use and maintaining efficiency, which is an impressive 99.8%. This means you can enjoy hot water without worrying too much about energy bills.

Installation is relatively straightforward with its wall-mount design and 3/4 inch NPT connections which simplify the setup process. The durable copper heating elements are also field-serviceable, contributing to the unit’s longevity. There are a few drawbacks to consider. The unit requires a 240V power supply and an adequate electrical setup, which might necessitate professional installation if your home isn’t equipped. It may not be powerful enough for larger households or homes with high demand for simultaneous hot water use.

Rating
10.0
Temperature Rise
Power Requirements
Size and Installation

Most important from
1947 reviews

Temperature Rise
You may feel the need to set the temp to 145 if converting from a traditional water heater tank, but it's unnecessary unless using multiple hot water devices simultaneously.
Power Requirements
Cheaper than Home Depot and pulls about 8kW upon use.
Size and Installation
Installed in a tiny house and works wonderfully.
#3

Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray

Rating
9.7
Flow Rate
Power Requirements
Energy Efficiency

Most important from
787 reviews

Flow Rate
With the Rheem RTEX-24, you never run out of hot water, even with high usage in a household.
Power Requirements
Despite needing more power during use, the heater remains off most of the time, contributing to energy savings.
Energy Efficiency
The workmanship is exceptional, and the heater operates with impressive efficiency.
Size and Installation
The unit is compact and heats water very quickly, making it a great space-saver and efficient solution.

The Rheem RTEX-24 is a solid choice for anyone looking for an electric tankless water heater, particularly for residential use. One of its key strengths is its impressive flow rate of up to 5.9 gallons per minute, making it suitable for medium to large households where multiple hot water outlets may be used simultaneously. Its self-modulating power control ensures that the heater adjusts energy use based on demand, which can help in energy savings. With an energy efficiency rating of 99.8%, this unit can significantly reduce your utility bills compared to traditional tank heaters.

The adjustable digital temperature display is user-friendly, allowing for easy temperature adjustments to find that just-right warmth. The compact design, with dimensions that allow for wall mounting, can save space in smaller homes.

There are a few considerations to keep in mind. The installation might require a professional, especially if you’re not handy, as it involves electrical connections that must be done correctly for safety. Additionally, while the heater’s specifications are strong, it may struggle if you have high hot water demands at multiple points at once, depending on the temperature rise needed and your incoming water temperature. Lastly, Rheem provides a warranty, but it's always good to check the specifics to ensure you’re covered in case of any manufacturing defects. If you’re seeking a reliable and efficient hot water heater for your home, the Rheem RTEX-24 is certainly worth considering.

Rating
9.7
Flow Rate
Power Requirements
Energy Efficiency

Most important from
787 reviews

Flow Rate
With the Rheem RTEX-24, you never run out of hot water, even with high usage in a household.
Power Requirements
Despite needing more power during use, the heater remains off most of the time, contributing to energy savings.
Energy Efficiency
The workmanship is exceptional, and the heater operates with impressive efficiency.
Size and Installation
The unit is compact and heats water very quickly, making it a great space-saver and efficient solution.

Buying Guide for the Best Electric Tankless Hot Water Heater

Choosing the right electric tankless hot water heater can significantly impact your comfort and energy efficiency at home. Unlike traditional water heaters, tankless models heat water on demand, which means they can provide a continuous supply of hot water without the need for a storage tank. To make an informed decision, it's important to understand the key specifications and how they relate to your specific needs.
Flow RateFlow rate, measured in gallons per minute (GPM), indicates how much hot water the unit can produce at a time. This is crucial because it determines whether the heater can meet your household's hot water demands. For example, a flow rate of 2-3 GPM is suitable for small households or single-point applications like a shower, while 4-6 GPM is better for larger households with multiple simultaneous hot water needs. Assess your household's peak hot water usage to choose the right flow rate.
Temperature RiseTemperature rise refers to how much the unit can increase the incoming water temperature. This is important because it affects how hot the water will be when it reaches your tap. For instance, if the incoming water is 50°F and you need it to be 120°F, the heater must provide a 70°F temperature rise. Higher temperature rise capabilities are necessary in colder climates where incoming water is colder. Consider your local water temperature and desired output temperature to determine the appropriate temperature rise.
Power RequirementsElectric tankless water heaters require a certain amount of electrical power to operate, typically measured in kilowatts (kW). This is important because it affects both the installation process and the unit's performance. Lower power units (around 10-15 kW) are suitable for smaller applications, while higher power units (20-30 kW or more) are needed for whole-house use. Ensure your home's electrical system can support the required power and consult an electrician if necessary.
Energy EfficiencyEnergy efficiency, often expressed as a percentage, indicates how effectively the unit converts electrical energy into hot water. Higher efficiency means lower energy consumption and reduced utility bills. Look for units with an efficiency rating of 90% or higher for the best performance. Consider your long-term energy savings when evaluating efficiency ratings.
Size and InstallationThe physical size of the unit and its installation requirements are important for ensuring it fits in your designated space and can be installed properly. Compact units are ideal for small spaces or point-of-use applications, while larger units may be necessary for whole-house systems. Check the dimensions and installation guidelines to ensure compatibility with your space and plumbing setup.
Warranty and SupportA good warranty and reliable customer support can provide peace of mind and protect your investment. Warranties typically cover parts and labor for a certain period, often ranging from 5 to 10 years. Consider the length and terms of the warranty, as well as the manufacturer's reputation for customer service, when making your decision.

FAQ

Most Popular Categories Right Now