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 20 Trend is a compact tankless water heater designed to provide on-demand hot water without the need for a storage tank. Its continuous flow feature means you won’t run out of hot water during showers, making it suitable for small to medium households. With a 19.2 kW power rating and a maximum flow rate of about 2 gallons per minute, it can handle multiple bathroom uses but may struggle with very large households needing simultaneous showers.

This model is energy-efficient thanks to its auto-modulation technology, which adjusts power based on water flow, reducing wasted energy. It’s also a space saver, with a slim design that mounts on the wall and requires no venting, making installation easier in tight spaces. The digital LED display allows easy temperature control between 68° and 140°F. While tankless heaters don’t have a traditional First Hour Rating (FHR), its continuous flow design compensates by providing hot water as needed.

The Tempra 20 Trend has strong safety features and certifications (ANSI, CSA, NSF, UL), ensuring reliable operation. You get a 7-year warranty against leaks and a 3-year parts warranty, which shows the brand’s confidence in durability. One thing to note is the electrical service requirement: it needs a 240V supply and a 125-amp minimum service, which might require an upgrade in some homes. This heater is ideal if you want endless hot water in a small package and are comfortable with the electrical requirements. It’s quiet, efficient, and backed by solid warranties, but its flow rate means it’s better suited for moderate, not very high, hot water demand.

The Rheem RTEX-24 electric tankless water heater is a strong candidate for those seeking an efficient and space-saving solution for continuous hot water. With a maximum flow rate of up to 5.9 gallons per minute (GPM), it’s well-suited for smaller households or apartments where immediate hot water is a necessity. Its self-modulating power control ensures that the energy consumption aligns with your hot water usage, contributing to its impressive energy efficiency rating of 99.8%. This makes it a cost-effective choice for anyone looking to lower their utility bills while still enjoying ample hot water on demand.

The adjustable digital temperature display with ON/OFF dial control is user-friendly, making it easy to set the desired temperature. Additionally, the compact design (17.63" x 18.25") allows for wall mounting in tight spaces, a significant advantage for those with limited installation options.

However, there are a few drawbacks to consider. The unit requires a considerable electrical installation, including a dedicated 240V outlet, which might entail additional setup costs if you don't already have the proper wiring in place. While the maximum flow rate is decent, larger families or homes with multiple simultaneous hot water demands (like multiple showers running at once) may find it insufficient. Also, it lacks a traditional tank, which means there’s no hot water storage; if the demand exceeds its flow rate, you might experience short interruptions.