The Voltex AL (anti-leak) hybrid electric heat pump water heater features integrated leak detection, smart connectivity, updated water connections for professionals and the highest overall Uniform Energy Factor (UEF) of 4.02 with the 66-gal. unit and the highest 50-gal. UEF at 3.8, the company says. It is also available in an 80-gal. model. The unit can save homeowners up to $521 per year on utility bills when compared to a standard electric water heater.