10 Best Electric On Demand Water Heater 2026 in the United States

The Rheem RTEX-24 Electric Tankless Water Heater is a solid choice for those looking for on-demand hot water. With a power output of 24kW and a flow rate of up to 5.9 gallons per minute (GPM), it offers consistent and continuous hot water supply, making it suitable for medium to large households.

The adjustable digital temperature display and self-modulating power control add convenience and efficiency, allowing users to customize their water temperature easily. Its 99.8% energy efficiency rating means it is environmentally friendly and could help in lowering energy bills over time.

The LED display is an added feature that enhances user experience by providing clear temperature readings. Installation is straightforward, thanks to the wall mount design and 3/4

The Rheem 18kW 240V Tankless Electric Water Heater is a solid option for those looking to efficiently supply hot water on demand. With a flow rate of up to 4.4 gallons per minute (GPM), it can cater to smaller households or applications requiring moderate hot water supply, making it ideal for apartments or homes with limited space.

One of its strengths is the 99.8% energy efficiency, which means it consumes less energy compared to traditional water heaters. This can help save on electricity bills over time. The unit features an external digital thermostatic control with an LED display, allowing users to set temperatures with +/- 1 degree accuracy, which is a handy feature for precise control and comfort. The self-modulating technology adjusts the power based on the demand for hot water, ensuring consistent performance. Additionally, the durable copper immersion heating elements are field-serviceable, which can simplify maintenance and repair.

However, there are some limitations to consider. The maximum flow rate of 4.4 GPM may not be sufficient for larger households or simultaneous high-demand situations, such as running multiple showers at once. Also, while the installation is straightforward with bottom water connections, it may still require professional assistance for optimal setup, especially for those unfamiliar with plumbing. It’s also worth noting that while the product dimensions are compact (14.5 inches wide and 18.25 inches high), its wall-mounted design might not suit every installation preference.

The Stiebel Eltron Tempra 29 Plus is a powerful electric tankless water heater designed to provide a continuous and unlimited supply of hot water on demand. With a maximum flow rate of about 3 gallons per minute and a high power output of 28.8 kW, it can handle the hot water needs for larger households or multiple fixtures running at the same time. Its ability to manage a strong temperature rise means you can expect hot water even if your incoming water is quite cold. The heater is also energy efficient, which helps reduce electricity bills compared to traditional tank heaters.

Installation requires a dedicated 240-volt electric connection with three 40-amp circuit breakers and heavy wiring, so it’s best suited for homes with sufficient electrical capacity or those willing to upgrade their electrical system. The unit’s compact wall-mounted design saves space and doesn’t need venting, making it a neat option for small utility areas. The LED display and two temperature memory presets add convenience for personalized use.

The installation complexity and high electrical demands might be challenging or costly for some homes. Also, its flow rate might be limiting if you have a very large household with simultaneous high water use beyond 3 GPM. Nevertheless, the brand’s reputation, positive customer reviews, and certifications provide assurance of reliability and quality. This heater is an excellent choice if you want an energy-saving, space-efficient system that delivers steady hot water for a mid-to-large home and supports multiple usages without running out. Just be sure your home’s electrical setup can handle its power needs.