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10 Best Tankless Electric Hot Water Heaters 2025 in the United States
#1
Winner
Stiebel Eltron Tankless Water Heater – Tempra 24 Plus – Electric, On Demand Hot Water, Eco, White, 20.2
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.
Rating
9.9
Chosen by1,195
Flow Rate
Temperature Rise
Power Requirements
Most important from
2083 reviews
#2
Stiebel Eltron Tankless Water Heater - Tempra 29 Trend – Electric, On Demand Hot Water, Eco, White
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.
Rating
9.8
Flow Rate
Temperature Rise
Power Requirements
Most important from
2083 reviews
#3
Rheem 18kW 240V Tankless Electric Water Heater, Gray
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.
Rating
9.7
Temperature Rise
Size and Installation
Most important from
1961 reviews
Top 10 Best Tankless Electric Hot Water Heaters 2025 in the United States
#1
Winner
9.9 score
Stiebel Eltron Tankless Water Heater – Tempra 24 Plus – Electric, On Demand Hot Water, Eco, White, 20.2
Stiebel Eltron Tankless Water Heater – Tempra 24 Plus – Electric, On Demand Hot Water, Eco, White, 20.2
Temperature Rise: 68°F to 140°F
Power Requirements: 150 A
Energy Efficiency: Energy Efficient
Size and Installation: 16.63"W x 14.5"H, Wall Mount
Chosen by 1195 this week
Stiebel Eltron Tankless Water Heater - Tempra 29 Trend – Electric, On Demand Hot Water, Eco, White
Stiebel Eltron Tankless Water Heater - Tempra 29 Trend – Electric, On Demand Hot Water, Eco, White
Flow Rate: 9.5 GPM
Power Requirements: 200 A
Energy Efficiency: High
Size and Installation: 16.63"W x 14.5"H, Wall Mount
Warranty and Support: 7-year leakage, 3-year parts
Rheem 18kW 240V Tankless Electric Water Heater, Gray
Rheem 18kW 240V Tankless Electric Water Heater, Gray
Flow Rate: 4.4 Gallons Per Minute
Power Requirements: 240 Volts
Energy Efficiency: 99.8%
Size and Installation: 14.5"W x 18.25"H, Wall Mount
EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with Patented Self Modulating Technology
EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with Patented Self Modulating Technology
Flow Rate: 1.3 to 3.1 gallons per minute
Power Requirements: 13KW, 240 volts, 54 amp draw
Energy Efficiency: 99% thermal energy efficient
Size and Installation: 11.5 x 8 x 3.75 inches, wall mount
Warranty and Support: Lifetime Warranty on electronics, exchanger
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray
Flow Rate: 5.9 Gallons Per Minute
Power Requirements: 240 volts, 24kW
Energy Efficiency: 99.8%
Size and Installation: 17.63"W x 18.25"H x 3.5"D
Related Products
Ranein Electric Tankless Water Heater, 18kW 240V on Demand Instant Endless Water Heater with LED Temperature Display for Residential Whole House Shower, Space Saving
Ranein Electric Tankless Water Heater, 18kW 240V on Demand Instant Endless Water Heater with LED Temperature Display for Residential Whole House Shower, Space Saving
Flow Rate: 4.3 Gallons Per Minute
Temperature Rise: 86°F to 131°F
Power Requirements: 2 x 40-amp breakers, 240V AC
Energy Efficiency: 99%
Size and Installation: 13.8" x 3.1" x 18.7", Wall Mount
Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater, GRAY
Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater, GRAY
Flow Rate: 3.17 GPM
Power Requirements: 54 amps at 13kW
Energy Efficiency: 99.8%
Size and Installation: 1W x 1H inches, 1/2 NPT adapters
EcoSmart ECO 27 Tankless Water Heater, Electric, 27-kW - Quantity 1, 17 x 17 x 3.5
EcoSmart ECO 27 Tankless Water Heater, Electric, 27-kW - Quantity 1, 17 x 17 x 3.5
Flow Rate: 2.7 to 6.5 GPM
Power Requirements: Three 40-amp double pole breakers
Energy Efficiency: 99%
Size and Installation: 17 x 17 x 3.5 inches
Warranty and Support: Limited lifetime warranty on electronics
Rheem RTEX-27 240V 3 Heating Chambers Residential Tankless Water Heater
Rheem RTEX-27 240V 3 Heating Chambers Residential Tankless Water Heater
Flow Rate: 0.11 Gallons Per Minute
Power Requirements: 27000 watts, 240 volts
Energy Efficiency: High
Size and Installation: 1"W x 1"H x 3.5"D
Warranty and Support: Customer support available
#10
8.0 score
Stiebel Eltron Tempra Plus 29 kW, tankless electric water heater with Self-Modulating Power Technology & Advanced Flow Control ™
Stiebel Eltron Tempra Plus 29 kW, tankless electric water heater with Self-Modulating Power Technology & Advanced Flow Control ™
Power Requirements: 220 Volts, 28.8 KW
Energy Efficiency: 15-20% energy saving
Size and Installation: 16.54 x 4.61 x 14.53 inches
Warranty and Support: 7 years leakage, 3 years parts
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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.