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

The Stiebel Eltron Tempra 24 Plus is a strong contender in the tankless electric hot water heater category. One of its standout features is the Advanced Flow Control, which ensures a consistent hot water temperature, minimizing interruptions during use. This is particularly advantageous for families or households with high hot water demands. The compact design not only saves space but also eliminates the need for venting, making it ideal for various installation environments.

Energy efficiency is another key strength. The unit incorporates auto-modulation to optimize energy usage, which can lead to noticeable savings on utility bills. The savings monitor is a helpful addition, allowing users to track their energy efficiency.

In terms of operation, the Tempra 24 Plus is user-friendly, featuring an electronic switch and a digital temperature display that enhances control over your water temperature settings. The maximum output temperature range of 68°F to 140°F offers flexibility, with a setting to limit maximum temperature for safety, particularly useful for homes with children. However, the requirement for a substantial electric service of at least 150 A may limit its installation options in some homes, especially older ones with lower electrical capacities. Additionally, the initial cost may be higher than traditional tank water heaters, which could be a concern for budget-conscious consumers. The Stiebel Eltron Tempra 24 Plus is an excellent choice for those seeking reliable, on-demand hot water while being mindful of space and energy consumption.

The Stiebel Eltron Tempra 29 Trend is an electric tankless hot water heater designed to provide on-demand hot water efficiently, making it a great choice for homeowners looking to upgrade their water heating system. One of its standout features is the continuous flow capability, which allows for unlimited hot water without interruption, ensuring you can enjoy long showers or multiple fixtures running simultaneously without running out of hot water. The small and sleek design means it won't take up much space, and since it doesn't require venting, it simplifies installation.

Energy efficiency is a strong point for the Tempra 29 Trend, thanks to its auto-modulation feature, which adjusts power use based on demand, potentially lowering energy bills. It operates silently, which can be a big plus for households sensitive to noise. The digital temperature display is user-friendly, allowing for easy adjustments and monitoring.

The product does have some limitations. It requires a significant electric service of 200 A, which may mean additional electrical upgrades for some homes. Also, while it performs well for many applications, larger households or simultaneous high-demand scenarios might find its maximum output of about 9.5 gallons per minute a bit limiting, especially when multiple outlets require hot water at once.

Warranty options are solid, with a 7-year leakage warranty and a 3-year parts warranty, giving customers peace of mind regarding reliability. This tankless water heater is well-suited for medium to large households that value space-saving designs and energy efficiency, but prospective buyers should ensure their electrical systems can accommodate the power requirements for optimal performance.

The Rheem 18kW 240V Tankless Electric Water Heater is designed for those looking for an efficient and space-saving hot water solution. With a flow rate of up to 4.4 gallons per minute, it can adequately meet the hot water demands of small to medium-sized households. Its self-modulating feature intelligently adjusts the power based on your hot water needs, ensuring energy efficiency, with an impressive efficiency rating of 99.8%. This can lead to cost savings on energy bills over time.

One of its highlights is the external digital thermostatic control with an LED display, which allows for precise temperature adjustments within a degree. This user-friendly interface makes it easy to monitor and set your preferred water temperatures. Installation is a breeze as well, thanks to its wall-mountable design and straightforward connection options, making it a suitable choice for DIY enthusiasts or professional installations alike. The compact size ensures it won't take up much space, making it ideal for areas where a traditional tank heater would be cumbersome.

However, there are some considerations to keep in mind. While the flow rate is satisfactory for many, larger households or those with high simultaneous usage may find it inadequate, especially during peak demand times. Additionally, the requirement for a dedicated 240V electrical connection may necessitate an upgrade if your current setup is not compatible. The Rheem 18kW unit is a solid choice for users seeking a compact and effective tankless electric water heater, but it may not be the best fit for larger families or high-demand situations.