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 Stiebel Eltron Tempra 20 Plus Tankless Water Heater offers some impressive features that address key needs for an electric-on-demand-water-heater. It has a flow rate of up to 3.79 liters per minute, which should be sufficient for most households. The power rating of 19.2 kW ensures that it can deliver a significant temperature rise, keeping your showers hot even if demand fluctuates. The advanced flow control technology helps maintain a consistent water temperature, providing comfort and preventing interruptions during hot showers.

Energy efficiency is a strong point as well; the unit has auto-modulation and electronic flow control, and a savings monitor helps track energy costs, making it eco-friendly and potentially cost-effective in the long run. It's compact and wall-mountable, saving space without the need for venting, which can be a big advantage for smaller homes or apartments. The installation requires a minimum 125 A electric service, which might necessitate an upgrade for some homes. The digital temperature display and preset buttons make operation straightforward, and the unit runs quietly.

The warranty is robust, offering 7 years against leakage and 3 years for parts, which provides some peace of mind. However, the maximum flow rate of 3.79 liters per minute may not suffice for larger households with multiple simultaneous hot water demands. Additionally, while it is energy-efficient, the initial cost and potential need for electrical upgrades might be a consideration for some users. This unit is best suited for average-sized homes that require a reliable and efficient solution for on-demand hot water.

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.