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

The Stiebel Eltron Tempra 29 Trend Tankless Water Heater is designed to provide continuous, on-demand hot water without interruptions. With a power rating of 28.8 kW, it can supply a consistent stream of hot water, making it suitable for whole-house use. The flow rate is not explicitly mentioned, but given its kW rating, it should handle moderate to high demands effectively. It offers a substantial temperature rise, with output water temperatures ranging from 68° to 140°F, which caters to various household needs.

Its compact size (16.63"W x 14.5"H) and sleek design make it space-efficient and visually unobtrusive, fitting well in small areas. The unit operates silently, which is a significant advantage for maintaining a peaceful environment. Installation requires a minimum recommended electric service of 200 A, which might necessitate an upgrade in older homes. No venting is required, simplifying the installation process.

The water heater comes with impressive safety features, including auto-modulation for energy savings and solid copper heating components, ensuring durability and reliability. Energy efficiency is emphasized through its eco-friendly design, making it a good choice for reducing energy consumption. The digital temperature display is user-friendly, and the product is backed by robust warranties (7-Year Leakage and 3-Year Parts). However, the significant power requirement might be a limitation for some households, and potential buyers should verify their electrical capacity before purchase. The Tempra 29 Trend offers reliable performance, efficient energy use, and ease of installation, making it a compelling option for those in need of a portable tankless electric hot water heater.

The Rheem 18kW 240V Tankless Electric Water Heater is a robust option for those seeking an efficient, portable hot water solution. With a flow rate of up to 4.4 GPM, it can handle moderate hot water demands, making it suitable for small to medium-sized homes or apartments. The 18kW power output ensures a consistent and substantial temperature rise, providing reliable hot water performance.

Its compact size (14.5"W x 18.25"H) enhances its portability, allowing it to fit in various spaces without much hassle. The installation process is straightforward due to the bottom 3/4 inch NPT water connections and threaded design for easy replacement, making it user-friendly for those who prefer a DIY approach. Additionally, the external digital thermostatic control with LED display offers precise temperature regulation, ensuring comfort and safety.

However, while the copper immersion heating elements are durable and serviceable, the energy efficiency could be a concern for some users, especially those with high electricity rates. It is important to note that while installation is simple, professional installation is recommended to ensure optimal performance and safety. In summary, this water heater is a reliable and user-friendly option for individuals or families needing an efficient, portable hot water solution with easy installation and precise temperature control.

The EcoSmart ECO 11 Electric Tankless Water Heater is a compact and efficient solution for small-scale hot water needs. With a power rating of 13KW at 240 volts and a maximum flow rate of 3.1 gallons per minute (GPM), it is well-suited for use in bathrooms, small sinks, office breakrooms, and other low-flow applications. One of its key strengths is the patented self-modulating technology, which ensures consistent performance and energy savings by heating water only when needed. This contributes to its impressive 99.8% energy efficiency rating, making it an environmentally friendly choice.

Additionally, its small size (11.5 x 8 x 3.75 inches) allows for flexible installation options, including wall mounting or point-of-use placement, thereby saving space in your home or office. It also features an LED display for easy temperature monitoring and control. However, there are a few drawbacks to consider. The unit requires a 54-amp draw, which may necessitate an electrical upgrade for some users. It also has a limited maximum flow rate, which might not be sufficient for larger households or multiple simultaneous hot water needs.

The lifetime warranty covers the heater itself but does not include labor or incidental damages, so potential repair costs should be taken into account. Despite these limitations, the EcoSmart ECO 11 is an excellent choice for those seeking a reliable, energy-efficient, and space-saving hot water solution for smaller-scale applications.