10 Best Electric Tankless Water Heaters 2026 in the United States

The Rheem RTEX-24 24kW 240V Electric Tankless Water Heater offers solid performance for households looking for a reliable source of on-demand hot water. One of its strong points is the flow rate, with the capacity to deliver up to 5.9 gallons per minute, which should be sufficient for multiple outlets running simultaneously. The unit's self-modulating power control and adjustable digital temperature display are user-friendly features that allow for precise temperature adjustments and energy savings, contributing to its high energy efficiency rating of 99.8%. This makes it an economical choice in the long run.

Additionally, the unit is compact, with dimensions of 17.63 inches wide and 18.25 inches high, making it easier to install in various spaces. It is designed for wall mounting, which can save floor space in tight utility areas. However, the power requirements are quite high at 24kW and 240V, which means it might require an upgrade to your electrical system if your current setup isn't compatible. This could add to the installation cost and complexity.

The unit also comes with necessary fittings and aerators, which is a plus. In conclusion, the Rheem RTEX-24 is an efficient and high-capacity option suitable for those who need consistent hot water and have the necessary power infrastructure.

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 8kW 240V Tankless Electric Water Heater is a compact and efficient choice for providing continuous hot water on demand. With a flow rate of up to 1.95 gallons per minute, it’s best suited for single sink use or small point-of-use applications rather than whole-house needs. Its 8kW power rating means it requires a 240V electrical supply, which is standard for many homes but should be confirmed to ensure compatibility.

The unit features a self-modulating power control, which adjusts energy use based on demand, helping to save electricity and provide consistent water temperature. The adjustable digital temperature display and ON/OFF dial control make it easy to set and monitor your preferred heat level. Installation is space-friendly, as the unit is wall-mounted and fairly small at about 8 by 13 inches, making it ideal for tight spaces.

Because of the lower flow rate, it might struggle to keep up if multiple outlets demand hot water simultaneously. Additionally, proper electrical wiring is needed to support the 8kW load. If you’re looking for a reliable electric tankless heater that excels for small-scale hot water needs and offers precise temperature control, this Rheem model is a solid, energy-conscious option.