10 Best Tankless Hot Water Heaters 2025 in the United States

The Stiebel Eltron Tempra 29 Trend is a strong contender in the tankless hot water heater market, particularly suitable for those seeking an efficient and space-saving solution for whole-home hot water needs. Its continuous flow feature ensures that you won’t run out of hot water during showers or while using multiple taps, which is a significant advantage for larger households. The energy efficiency of this model is commendable, with auto-modulation that helps save power when hot water is not in demand, making it an eco-friendly option.

The Ranein Natural Gas Tankless Water Heater offers a flow rate of up to 5.3 gallons per minute (GPM), making it suitable for medium-sized households with 3-5 outlet points operating concurrently. Its 130,000 BTU heating capacity provides instant hot water without the need for preheating, which is a significant advantage over traditional tank water heaters. The energy efficiency of this unit is tied to its natural gas fuel type, which can be economical for many users.

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.