10 Best Portable Water Heater 2025 in the United States

The Stiebel Eltron Tempra 24 Plus is an electric tankless water heater that offers continuous hot water on demand with advanced flow control technology, ensuring comfort and preventing interruptions during use. Its sleek design is compact and saves space, making it a good fit for homes with limited room. The unit is eco-friendly, with energy-saving features such as auto-modulation and electronic water flow control.

The digital temperature display and preset memory buttons simplify operation, and the solid copper heating system adds to its reliability and performance. Safety features include the option to limit the maximum hot water temperature to prevent scalding, which is particularly useful for households with children or elderly members. Additionally, the product comes with substantial warranties, providing assurance on leakage and parts reliability for several years.

However, the high power requirement (150 A electric service) might be a drawback for those with older electrical systems, and the initial installation might require professional assistance due to the electrical specifications. Despite these considerations, the Stiebel Eltron Tempra 24 Plus is a robust choice for providing consistent hot water with efficient energy use and user-friendly controls.

The Rheem 18kW 240V Tankless Electric Water Heater is a powerful and efficient option for those needing a reliable source of hot water. With an 18,000-watt power source, it offers substantial heating capacity, providing a flow rate of up to 4.4 gallons per minute (GPM). This makes it suitable for households with moderate hot water demands.

The external digital thermostatic control with a precise LED display allows for easy and accurate temperature adjustments, ensuring user comfort and safety. The advanced self-modulation technology helps optimize energy usage by adjusting power according to the hot water demand, which is both efficient and eco-friendly.

The Rheem RTEX-24 Electric Tankless Water Heater offers a solid performance for those needing an on-demand and consistent hot water supply. With a 24kW power source, it is capable of delivering up to 5.9 gallons per minute, making it suitable for larger households or multiple simultaneous hot water uses. The adjustable digital temperature display and self-modulating power control are excellent for precise temperature management, allowing users to set and maintain their desired water temperature easily.

Safety is also considered with its sturdy build and reliable performance features, including a maximum pressure capacity of 150 PSI. However, at 17.8 pounds and designed for wall mounting, it may not be as portable as some other models on the market, making it less ideal for frequently moving around or for outdoor use. The installation might require professional help due to its electric and wall-mounted nature. The LED display adds a modern touch and makes it simple to monitor and adjust settings.

The Rheem RTEX-24 is highly efficient, with a 99.8% energy efficiency rating, which can save on electricity bills. It scores well on durability with a stainless steel finish, suggesting a long-lasting product, although its weight and mounting requirements might limit portability. This heater is best suited for indoor use in permanent locations where reliable and continuous hot water is essential.