9 Best Rheem Tankless Electric Hot Water Heaters 2025 in the United States

The Rheem 18kW 240V Tankless Electric Water Heater is an excellent choice for those seeking an efficient hot water solution for their home. One of its standout features is the flow rate of up to 4.4 gallons per minute, which is sufficient for providing hot water to multiple fixtures simultaneously in smaller households. This model is known for its impressive energy efficiency, boasting a 99.8% rating, which can lead to lower utility bills over time.

The external digital thermostatic control with an LED display allows for precise temperature adjustments, ensuring consistent hot water delivery. Its self-modulating technology is another strong point, as it automatically adjusts the power based on your hot water demand, enhancing its efficiency further. Installation is straightforward with bottom 3/4 inch NPT water connections, making it accessible for both professionals and handy homeowners. The durable copper heating elements are also field serviceable, which can save costs on repairs in the long run.

There are a few considerations to keep in mind. While the flow rate is suitable for smaller households, larger homes or families might find it lacking if they require simultaneous hot water use at multiple points. Additionally, as an electric unit, it may not be the best option for users in areas with frequent power outages, as it relies solely on electricity. The warranty and customer support from Rheem are generally strong, which can give peace of mind, but it's always wise to check the specifics based on your location.

The Rheem RTEX-24 is a solid choice for those in need of an electric tankless water heater. It boasts a powerful 24kW output, providing a flow rate of up to 5.9 gallons per minute, which is quite impressive for residential use. This means it can supply consistent hot water for multiple fixtures at once, making it ideal for larger households or situations where high demand is common. The self-modulating power feature helps in energy efficiency, ensuring that it uses only the necessary power to meet your hot water needs, with an impressive efficiency rating of 99.8%. This can lead to savings on energy bills over time.

The unit is designed for easy installation, being wall-mounted and suitable for indoor use. Its compact dimensions mean it can fit into smaller spaces without issue. The adjustable digital temperature display and ON/OFF dial control enhance user-friendliness, allowing for precise temperature adjustments.

There are some drawbacks to consider. The installation might require professional help for some users, especially if electrical work is needed to support the heater’s power requirements. Additionally, while the unit is efficient, it may struggle to provide high flow rates if multiple outlets are used simultaneously, depending on the inlet water temperature and desired output temperature.

The Rheem RTEX-36 is a powerful electric tankless water heater, offering a maximum flow rate of 6 gallons per minute (GPM). This is quite significant and should be sufficient for households with multiple bathrooms or high hot water demands. Powered by 36 kW, it ensures a robust and consistent heating performance, making it suitable for larger homes or small businesses. This model is particularly energy-efficient, boasting an impressive efficiency rate of 99.8%, which translates to lower energy bills and a smaller carbon footprint.

One of the standout features is its digital temperature control, allowing users to adjust the water temperature precisely to their liking, enhancing comfort and convenience. Its compact and stylish design makes it an attractive option for those with limited space, and the wall-mounting capability simplifies installation, although professional assistance might be necessary to meet the electrical requirements.

The Rheem RTEX-36 is also noted for its durability, reflected in positive customer reviews with an average rating of 4.4 out of 5 stars. Potential buyers should consider that its efficiency and power might come with slightly higher upfront costs compared to less powerful models. Additionally, while the unit's maximum temperature is adequate for most domestic uses, users in colder climates should assess if the temperature rise meets their needs. This product comes with a warranty, although the specifics aren't detailed here, it's advisable to confirm the terms and coverage for peace of mind. The Rheem RTEX-36 is an excellent choice for users seeking a reliable, efficient, and powerful electric water heater that can handle substantial hot water requirements efficiently.