Rheem’s Next Generation Hybrid Electric Water Heater is now in its fifth generation. It is over 400 percent more efficient compared to any standard electric tank-type water heater in market. Available May 2020, this ENERGY STAR rated water heater offers a new 40-gallon model size and is built with more advanced features for unparalleled energy efficiencies. The system is more eco-friendly than ever at up to 4.0 UEF compared to past generations, which further reduces operating costs. Also, the system’s premium model is now the industry’s only hybrid water heater built with LeakGuard, an integrated leak detection and auto-shutoff that limits water loss from the tank to just 20 ounces of water.