10 Best Electric On Demand Water Heater 2025 in the United States

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 EcoSmart ECO 11 Electric Tankless Water Heater is a compact and efficient solution for providing on-demand hot water for smaller applications such as a bathroom, small sink, or office breakroom. It boasts a maximum flow rate of 3.1 gallons per minute (GPM) and a power rating of 13 kW, ensuring it can deliver consistent hot water without running out. The patented self-modulating technology helps maintain the water temperature within 1 degree of the selected setting, enhancing efficiency and performance.

One of the standout features is its energy efficiency, with a reported 99% thermal efficiency, meaning it only heats water when needed, which can save on energy bills over time. Additionally, its small size (11.5 x 8 x 3.75 inches) makes it easy to install on a wall or at the point of use, saving valuable space compared to traditional tank heaters. The LED display adds convenience by providing clear temperature readings. However, it’s important to note that its effectiveness varies with the inlet water temperature and is best suited for low-flow applications. It may not be ideal for larger households or demanding hot water needs.

The product comes with a lifetime warranty on electronics, exchanger, and element, although it doesn’t cover labor costs or incidental damages. The EcoSmart ECO 11 is a reliable, energy-efficient option for users needing an on-demand water heater for smaller settings.

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