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10 Best Tankless Electric Hot Water Heaters 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 Tankless Water Heater – Tempra 24 Plus – Electric, On Demand Hot Water, Eco, White, 20.2

Rating
10.0
Chosen by1,199
Flow Rate
Temperature Rise
Power Requirements

Most important from
2078 reviews

Flow Rate
Continuous flow of hot water even when running two showers simultaneously.
Temperature Rise
Precise temperature control ensures you get the desired hot water without fuss.
Power Requirements
No power usage when not in use, offering instant hot water even after a long absence.
Energy Efficiency
Eco-friendly and cost-effective by only using necessary hot water.
Size and Installation
Impressively quiet and space-saving design makes it a game-changer for installation near living spaces.

The Stiebel Eltron Tempra 24 Plus is a strong contender in the tankless electric hot water heater category. One of its standout features is the Advanced Flow Control, which ensures a consistent hot water temperature, minimizing interruptions during use. This is particularly advantageous for families or households with high hot water demands. The compact design not only saves space but also eliminates the need for venting, making it ideal for various installation environments.

Energy efficiency is another key strength. The unit incorporates auto-modulation to optimize energy usage, which can lead to noticeable savings on utility bills. The savings monitor is a helpful addition, allowing users to track their energy efficiency.

In terms of operation, the Tempra 24 Plus is user-friendly, featuring an electronic switch and a digital temperature display that enhances control over your water temperature settings. The maximum output temperature range of 68°F to 140°F offers flexibility, with a setting to limit maximum temperature for safety, particularly useful for homes with children. However, the requirement for a substantial electric service of at least 150 A may limit its installation options in some homes, especially older ones with lower electrical capacities. Additionally, the initial cost may be higher than traditional tank water heaters, which could be a concern for budget-conscious consumers. The Stiebel Eltron Tempra 24 Plus is an excellent choice for those seeking reliable, on-demand hot water while being mindful of space and energy consumption.

Rating
10.0
Chosen by1,199
Flow Rate
Temperature Rise
Power Requirements

Most important from
2078 reviews

Flow Rate
Continuous flow of hot water even when running two showers simultaneously.
Temperature Rise
Precise temperature control ensures you get the desired hot water without fuss.
Power Requirements
No power usage when not in use, offering instant hot water even after a long absence.
Energy Efficiency
Eco-friendly and cost-effective by only using necessary hot water.
Size and Installation
Impressively quiet and space-saving design makes it a game-changer for installation near living spaces.
#2

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

Rating
10.0
Flow Rate
Temperature Rise
Power Requirements

Most important from
2078 reviews

Flow Rate
Its ability to provide a continuous flow of hot water without interruption is a standout feature.
Temperature Rise
Precise temperature control ensures you get the hot water you desire without any fuss.
Power Requirements
Absolutely no power usage when not in use, making it highly efficient.
Energy Efficiency
The unit is eco-friendly and cost-effective, using only the necessary hot water.
Size and Installation
The Stiebel Eltron Tempra 29 Trend delivers impressively quiet operation and a space-saving design.
Warranty and Support
It's a top brand in the market, confirmed by professional installers.

The Stiebel Eltron Tempra 29 Trend is an electric tankless hot water heater designed to provide on-demand hot water efficiently, making it a great choice for homeowners looking to upgrade their water heating system. One of its standout features is the continuous flow capability, which allows for unlimited hot water without interruption, ensuring you can enjoy long showers or multiple fixtures running simultaneously without running out of hot water. The small and sleek design means it won't take up much space, and since it doesn't require venting, it simplifies installation.

Energy efficiency is a strong point for the Tempra 29 Trend, thanks to its auto-modulation feature, which adjusts power use based on demand, potentially lowering energy bills. It operates silently, which can be a big plus for households sensitive to noise. The digital temperature display is user-friendly, allowing for easy adjustments and monitoring.

The product does have some limitations. It requires a significant electric service of 200 A, which may mean additional electrical upgrades for some homes. Also, while it performs well for many applications, larger households or simultaneous high-demand scenarios might find its maximum output of about 9.5 gallons per minute a bit limiting, especially when multiple outlets require hot water at once.

Warranty options are solid, with a 7-year leakage warranty and a 3-year parts warranty, giving customers peace of mind regarding reliability. This tankless water heater is well-suited for medium to large households that value space-saving designs and energy efficiency, but prospective buyers should ensure their electrical systems can accommodate the power requirements for optimal performance.

Rating
10.0
Flow Rate
Temperature Rise
Power Requirements

Most important from
2078 reviews

Flow Rate
Its ability to provide a continuous flow of hot water without interruption is a standout feature.
Temperature Rise
Precise temperature control ensures you get the hot water you desire without any fuss.
Power Requirements
Absolutely no power usage when not in use, making it highly efficient.
Energy Efficiency
The unit is eco-friendly and cost-effective, using only the necessary hot water.
Size and Installation
The Stiebel Eltron Tempra 29 Trend delivers impressively quiet operation and a space-saving design.
Warranty and Support
It's a top brand in the market, confirmed by professional installers.
#3

Rheem 18kW 240V Tankless Electric Water Heater, Gray

Rating
9.8
Temperature Rise
Size and Installation

Most important from
1959 reviews

Temperature Rise
You may feel the need to set the temp to 145 if you are converting from a water heater tank, but it's not necessary unless you have multiple hot water devices running simultaneously.
Size and Installation
Installed in a tiny house and works wonderfully.

The Rheem 18kW 240V Tankless Electric Water Heater is designed for those looking for an efficient and space-saving hot water solution. With a flow rate of up to 4.4 gallons per minute, it can adequately meet the hot water demands of small to medium-sized households. Its self-modulating feature intelligently adjusts the power based on your hot water needs, ensuring energy efficiency, with an impressive efficiency rating of 99.8%. This can lead to cost savings on energy bills over time.

One of its highlights is the external digital thermostatic control with an LED display, which allows for precise temperature adjustments within a degree. This user-friendly interface makes it easy to monitor and set your preferred water temperatures. Installation is a breeze as well, thanks to its wall-mountable design and straightforward connection options, making it a suitable choice for DIY enthusiasts or professional installations alike. The compact size ensures it won't take up much space, making it ideal for areas where a traditional tank heater would be cumbersome.

However, there are some considerations to keep in mind. While the flow rate is satisfactory for many, larger households or those with high simultaneous usage may find it inadequate, especially during peak demand times. Additionally, the requirement for a dedicated 240V electrical connection may necessitate an upgrade if your current setup is not compatible. The Rheem 18kW unit is a solid choice for users seeking a compact and effective tankless electric water heater, but it may not be the best fit for larger families or high-demand situations.

Rating
9.8
Temperature Rise
Size and Installation

Most important from
1959 reviews

Temperature Rise
You may feel the need to set the temp to 145 if you are converting from a water heater tank, but it's not necessary unless you have multiple hot water devices running simultaneously.
Size and Installation
Installed in a tiny house and works wonderfully.

Buying Guide for the Best Tankless Electric Hot Water Heaters

Choosing the right tankless electric hot water heater can significantly impact your comfort and energy efficiency at home. These devices provide hot water on demand, which means you don't have to worry about running out of hot water or wasting energy on heating water that you don't use. To make an informed decision, it's important to understand the key specifications and how they relate to your 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 meet your household's hot water demands. For example, a flow rate of 2-3 GPM is suitable for a small household with one or two people, while a larger household with multiple showers and appliances running simultaneously might need a flow rate of 5-7 GPM or higher. Assess your household's hot water usage to determine the appropriate flow rate for you.
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 temperature rise needed depends on the incoming water temperature and your desired hot water temperature. For instance, if your incoming water is 50°F and you want it to be 120°F, you need a heater that can provide a 70°F temperature rise. Consider your local water temperature and your hot water needs to choose a heater with the right temperature rise capability.
Power RequirementsTankless electric water heaters require a certain amount of electrical power to operate, typically measured in kilowatts (kW). This is important because it affects the heater's performance and your home's electrical system. Lower power heaters (around 10-15 kW) are suitable for smaller households or single-point applications, while higher power heaters (20-30 kW or more) are needed for larger households or whole-house applications. Check your home's electrical capacity and consult with an electrician if necessary to ensure compatibility.
Energy EfficiencyEnergy efficiency, often expressed as a percentage, indicates how effectively the heater converts electrical energy into hot water. Higher efficiency means less energy waste and lower utility bills. Most tankless electric water heaters have efficiency ratings between 90% and 99%. If energy savings are a priority for you, look for a model with a higher efficiency rating. However, even a slightly lower efficiency model can be a good choice if it meets your other needs and is more affordable.
Size and InstallationThe physical size of the tankless water heater and its installation requirements are important considerations. These heaters are generally compact, but you need to ensure you have enough space for installation and proper ventilation if required. Additionally, some models may require professional installation due to electrical or plumbing requirements. Consider where you plan to install the heater and whether you need professional help to ensure a smooth installation process.
Warranty and SupportThe warranty and support offered by the manufacturer can provide peace of mind and protect your investment. Warranties typically cover parts and labor for a certain period, ranging from a few years to a decade or more. Good customer support can also be valuable if you encounter any issues or have questions about your heater. Look for a model with a comprehensive warranty and positive reviews regarding customer service to ensure you have support if needed.

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