10 Best Electric Tankless Water Heaters 2025 in the United States

The Stiebel Eltron Tankless Heater – Tempra 36 Plus is a reliable choice for on-demand hot water. One of its main strengths is the ability to provide continuous and unlimited hot water, making it ideal for households with high hot water needs. Its sleek design is another advantage, as it saves space and requires no venting, making installation easier, especially in compact areas. The unit operates quietly due to its electronic switch activation, which can be a significant benefit for maintaining a peaceful home environment.

With a power requirement of 27 kW and 208 volts, ensure your home’s electrical system can support this heater, as it demands substantial power. This model also includes a LED display for easy monitoring and control, adding to user convenience. The copper-sheathed heating element housed in a copper cylinder ensures durable performance. The maximum flow rate is 1.5 gallons per minute, which might be limiting for larger households or simultaneous usage in multiple locations. However, the energy efficiency of this model is high, potentially saving on energy costs over time.

The warranty is another strong point, offering 7 years on leakage and 3 years on parts, which reflects confidence in the product's durability. Weighing 19 pounds and with dimensions of 16.63 inches wide by 14.5 inches high, it’s relatively easy to handle and install. This unit is best suited for small to medium-sized households or specific areas needing hot water on demand.

The Rheem 18kW 240V Tankless Electric Water Heater is a solid choice for those looking for an efficient and reliable source of hot water. With a maximum flow rate of up to 4.4 gallons per minute (GPM), it can meet the demands of small to medium households effectively. One of its standout features is the external digital thermostatic control with a precise +/- 1 degree accuracy, allowing users to easily set and maintain their desired water temperature.

Energy efficiency is another strong point, boasting an impressive 99.8% efficiency rating, which can help reduce electricity bills over time. The self-modulation technology adjusts power based on hot water demand, ensuring energy is used only when needed. Additionally, it is compact in size, making it suitable for installations in tighter spaces.

Installation is made easy with the bottom 3/4 inch NPT water connections and threaded fittings, which simplify the process for homeowners and professionals alike. However, it’s important to note that this model is designed for wall mounting, which may require additional considerations for some users. Some users may find that the 18kW power rating is not sufficient for larger households with multiple simultaneous hot water needs. While it serves well for typical use, those with higher demand might need to consider a more powerful unit. Additionally, it may require professional installation, which can add to the overall cost.

The Stiebel Eltron Tempra 29 Trend electric tankless water heater is designed for continuous, on-demand hot water, ensuring that you never run out of hot showers. Its main strengths lie in its compact and sleek design, which saves space and requires no venting, making it ideal for various installation settings. The unit is also eco-friendly, featuring auto-modulation to save energy and reducing waste when hot water is not needed. Additionally, its silent operation and easy-to-read digital temperature display add to its user-friendly experience.

The solid copper heating system ensures durability and efficient heating performance, capable of providing water temperatures ranging from 68° to 140°F. However, the unit does require a significant electrical setup, with a minimum recommended electric service of 200 A, which may not be suitable for all homes without electrical upgrades. Another consideration is the power consumption, as the 28.8 kW rating could lead to higher energy bills if usage is not monitored.

On the plus side, the product comes with reliable warranties – 7 years for leakage and 3 years for parts, providing peace of mind. This model is best suited for households that can accommodate its power requirements and are looking for an efficient, space-saving solution for continuous hot water supply.