- Delivers 64-gallon first hour rating
- Leak detection sensor sounds an audible alarm when water is detected
- Automatic shut-off valve closes valve on incoming cold water inlet when leak is detected to reduce property damage
- iCOMM™ Smart Connectivity allows you to control & monitor your water heater remotely via the free A. O. Smith app
- Long-lasting dual 5500 watt stainless steel elements for fast hot water recovery & reliable operation
- Patented Blue Diamond® glass tank lining protects against corrosion
- DynaClean™ automatic cleaning system protects against sediment build-up
- Stainless steel Coregard™ anode rod protects against corrosion longer than ordinary anodes
- Commercial-grade brass drain valve for durable and easy operation
- 8-year limited tank and parts warranty
Get smarter hot water from A. O. Smith. Our ProLine® Master Smart electric water heaters are designed with iCOMM™ Wi-Fi technology greater control, leak detection and protection to provide homeowners with peace of mind. With a 55-gallon (nominal) tank delivering 5,500 watts, the HESF-40 delivers a first hour rating of 64 gallons at an Uniform Energy Factor of 0.92. Environmentally-friendly insulation and factory-installed heat trap nipples reduce heat loss for maximum energy savings. This ProLine® water heater is designed with A. O. Smith's superior commercial-grade tank protection. Advanced tank features include stainless steel Coregard™ anode rod, Blue Diamond® glass lining and DynaClean™ automatic sediment-cleaning system, all designed to help protect the tank from the corrosive effects of water and extend the life of the water heater. All of these features are accompanied by a 10-year limited tank warranty. A. O. Smith’s ProLine® water heaters are residential products built to commercial-grade standard and are only available for purchase through professional wholesalers and contractors.