10 Best Electric Water Heaters 2025 in the United States

The Rheem 18kW Tankless Electric Water Heater is a solid choice for those looking for an efficient and space-saving solution to hot water needs. Its compact size (14.5"W x 18.25"H) makes it ideal for homes with limited space, and the wall-mount design allows for easy installation. With a maximum flow rate of 4.4 gallons per minute, it can adequately serve smaller households or apartments, meeting the demands for showers and other hot water needs simultaneously.

One of the key strengths of this model is its impressive energy efficiency, boasting a 99.8% efficiency rating. This not only helps reduce energy bills but also makes it an eco-friendly option. The external digital thermostatic control with LED display allows for precise temperature adjustments, which can be a great feature for users who value control over their hot water supply.

There are some considerations to keep in mind. While the recovery rate is decent for its size, larger families might find the output insufficient during peak usage times. Additionally, installation might require a professional, especially if your existing plumbing does not match the specifications. Some customers have also noted that while the unit is generally reliable, it may not handle extremely high volumes of hot water demand as effectively as larger tank systems.

The warranty and customer service provided by Rheem is a plus, offering peace of mind should any issues arise. Safety features are also included, which is essential for households with children. The Rheem 18kW Tankless Electric Water Heater is best suited for smaller homes or apartments focused on energy efficiency and compact design, but larger families may need to consider their hot water demands before making a decision.

The Stiebel Eltron Tempra 24 Trend is a compact electric tankless water heater designed to provide endless hot water on demand, making it a good choice for those wanting continuous flow without running out. Its 24 kW power and 240V operation mean it can handle a decent-sized household's hot water needs, though it requires a strong electrical service (recommended 150 A), which might need upgrading in some homes. Since it heats water as you use it, there's no storage tank, saving space and avoiding standby heat loss, which helps with energy efficiency. The unit features auto-modulation, adjusting power based on your hot water demand to reduce energy waste.

Its size (about 16.6" wide and 14.5" high) and wall-mount design make it ideal for smaller installation spaces. The LED digital temperature display is easy to read, and the heating elements inside are made of solid copper, known for durability and efficient heat transfer. The heater provides water temperature control between 68°F and 140°F, suitable for most household needs. The 7-year warranty against leaks and a 3-year parts warranty reflect confidence in reliability. Installation requires some electrical know-how due to its power demands, which might mean professional help is needed. It operates silently, adding to comfort.

If your household has very high simultaneous demand (multiple showers, appliances at once), its flow rate might limit how much hot water can be delivered at once, so checking your usage patterns is important. This heater is well-suited for homeowners looking for energy-efficient, space-saving, and reliable hot water on demand, especially in homes with adequate electrical infrastructure.

The Stiebel Eltron Tempra 36 Plus is a powerful tankless electric water heater that delivers on energy efficiency and space-saving design. Its digital temperature control allows you to set water temperature precisely, helping to reduce energy waste. Thanks to Self-Modulating Power Technology and Advanced Flow Control, it adjusts power use based on demand, which can save you 15-20% on your electric bill compared to traditional heaters.

With a 26,000-watt power rating and 240-volt requirement, it supports high water flow, making it suitable for larger homes or those with multiple simultaneous hot water needs. However, it requires a substantial electric service (minimum 300 amps) and draws 150 amps itself, which might necessitate an electrical upgrade depending on your home's setup. The compact size (about 16.5" wide by 14.5" high and 4.6" deep) allows it to fit easily on a wall without taking much space, and no venting is required, simplifying installation. As a tankless model, it provides continuous hot water without the limits of tank capacity.

The heater comes with a solid warranty—7 years against leaks and 3 years on parts—and includes safety features like built-in flow control to prevent overheating. Although this model is discontinued and installation can be complex due to its electrical demands, it remains a strong option for those seeking an efficient, reliable tankless electric water heater in a compact form, particularly if their electrical system can support its high power needs.