10 Best Commercial Tankless Electric Hot Water Heaters 2026 in the United States

The Rheem RTEX-24 is a 24kW, 240V electric tankless water heater designed for commercial use. Its standout feature is the ability to deliver a high flow rate of up to 5.9 gallons per minute (GPM), which means it can supply hot water to multiple fixtures simultaneously, a beneficial trait for commercial settings.

Its self-modulating power control ensures efficient energy usage, achieving an impressive 99.8% energy efficiency, making it a cost-effective choice for businesses looking to reduce energy bills. The adjustable digital temperature display and ON/OFF dial control make it user-friendly, allowing precise temperature adjustments.

Installation is simplified with bottom 3/4

The Rheem 18kW 240V Tankless Electric Water Heater is a strong contender in the commercial tankless electric water heater category. With a flow rate of up to 4.4 gallons per minute (GPM), it can efficiently supply hot water for various applications, making it ideal for small businesses or residential settings where space-saving is crucial. The unit features advanced self-modulation technology that adjusts power usage based on hot water demand, improving energy efficiency, which is rated at an impressive 99.8%. This could lead to significant savings on energy bills, particularly in environments with fluctuating hot water needs.

Installation is straightforward, with bottom 3/4 inch NPT water connections and a wall-mount design that is simple to set up. The external digital thermostatic control with LED display allows for precise temperature adjustments, catering to specific user preferences with accuracy to +/-1 degree. The durable copper immersion heating elements further enhance the product's longevity, and being field serviceable means maintenance can be done without needing to replace the entire unit.

There are some considerations to keep in mind. While the flow rate is suitable for residential or light commercial use, larger businesses with higher hot water demands might find this unit insufficient. The weight of 14.78 pounds is relatively light for its size, but some users might still prefer a more robust model depending on their specific needs.

The Stiebel Eltron Tempra 24 Plus is a well-regarded tankless electric water heater suitable for both residential and commercial use. One of its standout features is its advanced Flow Control technology, which ensures a consistent water temperature, even when demand fluctuates. This is excellent for preventing interruptions during long showers or multiple simultaneous hot water usages.

In terms of design, the Tempra 24 Plus is compact and energy-efficient, making it ideal for those looking to save space while also reducing energy costs. Its sleek, white casing is attractive and it requires no venting, simplifying installation. The heater also has a digital display for easy temperature management, allowing users to set their desired hot water temperature with preset options.

Potential buyers should be mindful of the installation requirements, as it needs a minimum electric service of 150 A, which might necessitate an electrical upgrade in some homes or businesses. Additionally, while it performs efficiently, there might be limitations in flow rate during high-demand situations, as it can reduce water flow to maintain temperature. This could be a concern for larger households or commercial settings where multiple outlets are used simultaneously. Durability is supported by a respectable warranty period, offering 7 years for leakage and 3 years for parts, giving peace of mind regarding long-term reliability. The Stiebel Eltron Tempra 24 Plus is an excellent choice for those needing a reliable and efficient hot water solution, particularly in spaces where energy conservation is a priority. Just ensure that your electrical system can support its requirements to fully enjoy its benefits.