A.O. Smith continues to lead the way in residential and commercial water heating with close to 70 years of innovative hot water solutions. The HPTU-66N features A.O. Smith's latest high efficiency electric water heating technology. By using an electric heat pump rather than resistive heating elements the HPTU line offers money saving efficiency, with a 3.17 Uniform Energy Factor. A 66 gallon tank and multiple operating modes allow the unit to fit nearly any hot water need. Additional quality of life features such as backup electric elements, and a Coreguard anode rod keep the HPTU-66N running reliably and efficiently even in periods of high demand. High Efficiency Electric Hot Water The A.O. Smith Voltex line heats water with a high efficiency electric heat pump rather than conventional electric methods. This provides efficient hot water while also helping to dehumidify and cool the ambient air around the unit. Multiple Operating Modes The HPTU-66N comes with 3 different operating modes: Efficiency, Hybrid, and Electric, to meet any and all hot water needs. Hybrid mode automatically adjusts between the compressor and heating element. Vacation mode reduces costs for up to 99 days. Coreguard Anode Rod The stainless steel anode rod core helps extend the life of the heater by protecting it from the corrosive effects of hot water. Coreguard technology helps to extend the life more than that of a standard rod. User-Friendly Electronic Interface A built-in easy to read controller on the unit gives you easy access to temperature settings, operating mode, and multiple diagnostics to make sure your unit is running exactly how you want it.