10 Best Compact Tankless Electric Hot Water Heaters 2025 in the United States

The Stiebel Eltron Tempra 29 Trend is a compact and energy-efficient tankless electric water heater that's great for providing continuous hot water on demand. Its sleek white design makes it a space saver, fitting well in tight spaces and eliminating the need for venting. With a powerful 28.8 kW rating, it delivers an impressive water temperature range from 68°F to 140°F, ensuring hot showers whenever needed without interruption.

The digital temperature display is user-friendly, and the unit operates silently, which is a plus for households looking to minimize noise. Additionally, the auto-modulation feature helps save energy by adjusting the power based on water demand, making it eco-friendly. The solid copper heating system adds to its durability and reliability.

The 7-year leakage warranty and 3-year parts warranty offer peace of mind and reflect the brand’s confidence in the product's quality. However, it’s essential to note that the unit requires a minimum electrical service of 200 A, which might be a consideration for homes with lower electrical capacity. If you have the appropriate electrical setup, the Tempra 29 Trend is a robust option for consistent and efficient hot water supply in your home.

The Stiebel Eltron Tempra 24 Plus tankless electric water heater is designed to deliver continuous on-demand hot water for your entire household. With its advanced flow control technology, the water temperature remains consistent, ensuring those luxurious long showers won't get interrupted even if the demand is high. This model provides an impressive 24kW power rating and can heat water to a range of 68° to 140°F, suitable for various uses.

The unit is also eco-friendly, thanks to its auto-modulation feature and electronic water flow control, which help save energy and reduce your utility bills. Additionally, the small and sleek design of this heater allows for easy wall mounting and space-saving installation without the need for venting, making it ideal for homes with limited space. The digital display and user-friendly preset temperature and memory buttons make operation straightforward and convenient.

However, it requires a minimum electric service of 150 amps, which may necessitate an electrical upgrade in some homes. The included warranties (7-year leakage and 3-year parts) provide some peace of mind regarding durability and reliability. While the flow rate won't match that of larger tank heaters, its performance is solid for its size and category. This model will be particularly beneficial in smaller homes or for users looking to save space and energy while still enjoying the convenience of endless hot water.

The Rheem 18kW 240V Tankless Electric Water Heater is a compact and efficient solution for your hot water needs. One of its standout features is the external digital thermostatic control with an LED display, offering precise temperature adjustments within a one-degree accuracy, which allows for more consistent water temperature. The heater uses advanced self-modulation technology to adjust power based on the hot water demand, which can contribute to energy efficiency and potentially lower electricity bills. It has a flow rate of up to 4.4 gallons per minute (GPM), making it suitable for small to medium households, especially those with lower simultaneous hot water needs.

The heater is powered by 18,000 watts, ensuring quick heating capabilities. However, keep in mind that the higher power rating may require adequate electrical infrastructure in your home. The durable copper immersion heating elements are field serviceable, adding to the product's longevity and ease of maintenance. Installation is relatively simple, thanks to the bottom 3/4 inch NPT water connections and threaded design for easy replacement. The compact dimensions (14.5 inches wide by 18.25 inches high) allow it to fit in tight spaces, which is a significant advantage for homes with limited installation areas.

This Rheem model is ideal for those who need a reliable, space-saving water heater with advanced temperature control features, but should verify installation requirements beforehand.