Prestige Series condensing tankless gas water heaters from Rheem include built-in recirculation to provide homeowners with instant hot water at the tap while reducing water waste. The high-efficiency tankless water heaters deliver continuous hot water, as the built-in recirculation pump pushes water through the heat exchanger in a loop to prevent cold-water bursts. The units are easy to service and install. When installed at the furthest fixture, the crossover valve accessory converts the cold-water line into a recirculation return, eliminating the need to run new plumbing in existing homes. The units are Energy Star certified, with a 0.94 UEF rating. They are 1/2-inch gas line compatible and contain an ultralow NOx burner. Options include up to 100 feet of PVC venting and the ability to common vent two units, creating opportunities for more flexible and versatile installations. 800-621-5622; www.rheem.com.