10 Best Electric Tankless Water Heaters 2026 in the United States
#1
Winner
Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray
The Rheem RTEX-24 24kW 240V Electric Tankless Water Heater offers solid performance for households looking for a reliable source of on-demand hot water. One of its strong points is the flow rate, with the capacity to deliver up to 5.9 gallons per minute, which should be sufficient for multiple outlets running simultaneously. The unit's self-modulating power control and adjustable digital temperature display are user-friendly features that allow for precise temperature adjustments and energy savings, contributing to its high energy efficiency rating of 99.8%. This makes it an economical choice in the long run.
Rating
10.0
Chosen by1,176
Flow Rate
Power Requirements
Energy Efficiency
Most important from
3947 reviews
#2
Stiebel Eltron Tankless Water Heater – Tempra 36 Plus – Electric, On Demand Hot Water, Eco, White
The Stiebel Eltron Tankless Heater – Tempra 36 Plus is a reliable choice for on-demand hot water. One of its main strengths is the ability to provide continuous and unlimited hot water, making it ideal for households with high hot water needs. Its sleek design is another advantage, as it saves space and requires no venting, making installation easier, especially in compact areas. The unit operates quietly due to its electronic switch activation, which can be a significant benefit for maintaining a peaceful home environment.
Rating
9.4
Flow Rate
Temperature Rise
Power Requirements
Most important from
310 reviews
#3
Rheem 18kW 240V Tankless Electric Water Heater, Gray
The Rheem 18kW 240V Tankless Electric Water Heater is a solid choice for those looking for an efficient and reliable source of hot water. With a maximum flow rate of up to 4.4 gallons per minute (GPM), it can meet the demands of small to medium households effectively. One of its standout features is the external digital thermostatic control with a precise +/- 1 degree accuracy, allowing users to easily set and maintain their desired water temperature.
Rating
9.1
Temperature Rise
Power Requirements
Size and Installation
Most important from
3947 reviews
Top 10 Best Electric Tankless Water Heaters 2026 in the United States
#1
Winner
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: 24kW, 240V
Energy Efficiency: 99.8%
Size and Installation: 17.63"W x 18.25"H, Wall Mount
Chosen by 1176 this week
Stiebel Eltron Tankless Water Heater – Tempra 36 Plus – Electric, On Demand Hot Water, Eco, White
Stiebel Eltron Tankless Water Heater – Tempra 36 Plus – Electric, On Demand Hot Water, Eco, White
Flow Rate: 1.5 Gallons Per Minute
Power Requirements: 27 kW, 208 volts
Energy Efficiency: High
Size and Installation: 16.63"W x 14.5"H, Mounting
Warranty and Support: 7 years leakage, 3 years 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: 18kW 240V
Energy Efficiency: 99.8%
Size and Installation: 14.5"W x 18.25"H, Wall Mount
Stiebel Eltron Tankless Water Heater – Tempra 29 Plus – Electric, On Demand Hot Water, Eco, White
Stiebel Eltron Tankless Water Heater – Tempra 29 Plus – Electric, On Demand Hot Water, Eco, White
Flow Rate: 3 Gallons Per Minute
Power Requirements: 240V, 3x40A breakers, 200A service
Energy Efficiency: High Efficiency
Size and Installation: 16.63"W x 14.5"H, Wall-mount
Stiebel Eltron Tankless Water Heater - Tempra 20 Trend – Electric, On Demand Hot Water, Eco, White
Stiebel Eltron Tankless Water Heater - Tempra 20 Trend – Electric, On Demand Hot Water, Eco, White
Flow Rate: 2.01 Gallons Per Minute
Temperature Rise: 68°F to 140°F
Power Requirements: 240 Volts, 125 amps
Energy Efficiency: Auto-modulation
Size and Installation: 16.63"W x 14.5"H
Warranty and Support: 7-year leakage, 3-year parts
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Up to 35% off
Stiebel Eltron Tankless Water Heater - Tempra 36 Trend – Electric, On Demand Hot Water, Eco, White
Stiebel Eltron Tankless Water Heater - Tempra 36 Trend – Electric, On Demand Hot Water, Eco, White
Power (Kilowatts, kW): 36 KW
Temperature Rise: 68°F to 140°F
Electrical Requirements: 240V, min 300-amp service
Size and Mounting: 16.63"W x 14.5"H, Wall Mount
Control Features: LED Display, digital temp control
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
Temperature Rise: 68° to 140°F
Power Requirements: 200 A
Energy Efficiency: auto-modulation saves energy
Size and Installation: 16.63"W x 14.5"H
Warranty and Support: 7 years leakage, 3 years parts
WINTEMP 36kW Tankless Electric Water Heater 240V, Instant On-Demand Endless Hot Water, Up to 8.7 GPM, LED Temperature Display, Whole House Supply, WiFi Control, ETL Certified
WINTEMP 36kW Tankless Electric Water Heater 240V, Instant On-Demand Endless Hot Water, Up to 8.7 GPM, LED Temperature Display, Whole House Supply, WiFi Control, ETL Certified
Flow Rate (Gallons Per Minute, GPM): 8.7 Gallons Per Minute
Power (Kilowatts, kW): 36 KW
Temperature Rise: Up to 140°F
Electrical Requirements: 240V, max 150 amps, multiple breakers
Size and Mounting: 13.7"W x 21.1"H, wall-mounted
Control Features: WiFi remote, LED display, overheat protection
Rheem 11kW 240V Tankless Electric Water Heater
Rheem 11kW 240V Tankless Electric Water Heater
Flow Rate: 2.68 Gallons Per Minute
Power Requirements: 240 Volts
Size and Installation: 8.25"W x 12.63"H, Wall Mount
Warranty and Support: Decent warranty from Rheem
#10
Rheem 3.5kW 120V Point of Use Thermostatic Tankless Electric Water Heater
Rheem 3.5kW 120V Point of Use Thermostatic Tankless Electric Water Heater
Flow Rate (Gallons Per Minute, GPM): 0.9 Gallons Per Minute
Power (Kilowatts, kW): 3.5 kilowatts
Electrical Requirements: 120V, 30-amp breaker
Size and Mounting: 10.88"W x 5.88"H, Wall mount
Control Features: Thermostatic control, 80-140°F adj.
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Buying Guide for the Best Electric Tankless Water Heaters
When shopping for an electric tankless water heater, it's important to match the appliance to your household's needs since these devices provide hot water on demand and do not store it in a tank. The right model can offer unlimited hot water, save space, and improve energy efficiency, but picking one that's too small can leave you with lukewarm showers and other inconveniences. Before making your choice, consider the water usage patterns in your home and the installation constraints. Understanding the most important specifications will help you decide which heater best fits your household's requirements and ensures you enjoy reliable hot water whenever you need it.Flow Rate (Gallons Per Minute, GPM)Flow rate tells you how much hot water the unit can supply per minute. This is crucial because different activities require different amounts of hot water—for example, a shower uses more than a sink. Flow rates are divided into low (1–2 GPM), medium (2–4 GPM), and high (4+ GPM). Smaller homes or apartments with just one or two points of use at a time can opt for lower flow rates, while larger homes or those needing to run multiple showers and appliances at once should look for higher GPM values. Consider your simultaneous water needs to choose a flow rate that keeps up with your household usage.
Power (Kilowatts, kW)The power rating, measured in kilowatts, determines how quickly the water heater can heat the water as it passes through. Higher power means the unit can handle colder incoming water and higher flow rates. Power is often segmented into low (under 12 kW), medium (12–24 kW), and high (24+ kW). Choose a power rating that matches your desired flow rate and local climate—colder regions need more power to heat up incoming water, while smaller homes in warmer climates may need less.
Temperature RiseTemperature rise is the increase in water temperature the heater can achieve as water passes through. This is important because colder incoming water needs a larger temperature rise to reach comfortable hot water temperatures. Units are designed for certain temperature rises at different flow rates—higher temperature rise at a given flow rate means better performance in cold climates. If you live in a cooler region or expect heavy use, seek out models rated for higher temperature rises at your intended flow rate.
Electrical RequirementsInstallations of these water heaters require certain electrical specifications such as amperage and breaker size. This is important because your home’s existing electrical system must be able to support the heater safely. Requirements range from modest (can run on standard circuits) to heavy-duty (requires new dedicated circuits). Check your current electrical setup and consult with a professional if necessary; pick a model that fits your electrical system or be prepared for possible upgrades.
Size and MountingThese units are generally much smaller than tank heaters, but their physical size and required clearance still matter, especially if you have limited installation space. Sizes are typically compact (easy to fit under sinks), medium (wall-mounted for small spaces), and larger models (need more wall space). Check where you want to install the unit and see what physical size fits best without crowding or causing installation issues.
Control FeaturesModern tankless water heaters often come with features such as digital displays, adjustable temperature settings, and remote controls. These controls make it easier to fine-tune water temperature and monitor performance. Some are simple, with manual dials, while more advanced models offer precise and programmable digital controls. Consider your preference for ease of use—if you want more control over your water temperature and status indicators, choose a model with advanced digital features.