10 Best Commercial Tankless Electric Hot Water Heaters 2025 in the United States

The Stiebel Eltron Tempra 36 Trend is a solid choice for those seeking a reliable commercial tankless electric hot water heater. With a flow rate of 0.77 gallons per minute and a power rating of 36 kW, it delivers an impressive temperature rise, making it suitable for larger households or small commercial settings that require consistent hot water. One of its standout features is the continuous flow capability, ensuring that hot water is available on demand, which is particularly beneficial for busy environments.

Energy efficiency is another strength of this model. The auto-modulation feature helps conserve energy by adjusting the power output based on demand, leading to savings on utility bills. Additionally, the compact design requires no venting, making installation easier and saving space in tight locations.

However, there are some considerations to keep in mind. The Tempra 36 Trend requires a substantial electric service of at least 300 A, which might not be suitable for all homes or businesses without substantial electrical infrastructure. The installation might also necessitate a professional, adding to the overall cost. Furthermore, while it operates silently, some users may find the maximum flow rate slightly limiting if multiple hot water outlets are being used simultaneously. Durability is addressed with a solid warranty: a 7-year leak warranty and a 3-year parts warranty, which suggests confidence in the product's longevity.

The Stiebel Eltron Tempra 29 Plus is a powerful tankless electric water heater designed to supply continuous and unlimited hot water on demand. Its sleek design saves space and eliminates the need for venting, making it an excellent choice for commercial settings. With a flow rate of up to 3 gallons per minute, this heater can efficiently meet high hot water demands. The LED display and two temperature memory presets add convenience, allowing users to easily adjust settings to their preference.

Additionally, its eco-friendly design promotes energy efficiency, a significant benefit for commercial operations mindful of energy costs and environmental impact. However, the unit requires a substantial power supply, needing hard-wired 240 or 208-volt service, three separate 40 amp breakers, and a minimum 200 amp total service to the residence. This could be a challenge for locations without an existing robust electrical infrastructure. Moreover, its installation requires professional expertise due to these electrical requirements.

The durability is emphasized by its robust build quality and certification standards (CSA, NSF, UL, ANSI). The Tempra 29 Plus does not require ongoing battery replacements, reducing long-term maintenance efforts. Despite its higher upfront cost, its efficiency and low maintenance needs make it a potentially cost-effective option in the long run. Ideal for commercial enterprises needing reliable and steady hot water supply, it balances performance, efficiency, and user-friendly features well.

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.