10 Best Tankless Hot Water Heaters 2025 in the United States

The Rinnai RX199iN is a powerful tankless water heater that stands out for its impressive flow rate of up to 11.1 gallons per minute, making it suitable for homes with multiple fixtures needing hot water simultaneously. It's designed to operate on either natural gas or propane, giving you flexibility depending on your fuel source. The energy efficiency is top-notch, boasting a UEF rating of .98, which means it uses energy very effectively, potentially saving you on utility bills.

The EcoSmart ECO 11 electric tankless water heater is a compact and energy-efficient choice ideal for small spaces like bathrooms, office breakrooms, or point-of-use applications. It delivers continuous hot water on demand without the need for a storage tank, which helps save energy since it only heats water when needed. With a maximum flow rate of about 3.1 gallons per minute, it works well for low-demand situations, but it might struggle if you need to run multiple showers or faucets at the same time.

The Rheem 18kW 240V Tankless Electric Water Heater in Gray offers several appealing features for those in need of a compact and efficient water heating solution. The primary advantages of this model include its advanced self-modulation technology, which helps adjust power based on the hot water demand, ensuring energy efficiency and cost savings. Additionally, it boasts a flow rate of up to 4.4 GPM, which is suitable for small to medium households, providing enough hot water for multiple uses simultaneously.