this invention consists of a heat exchanger , a heating element , and a return line from a remote faucet to provide a constant circulatory flow of hot water through hot water distribution lines in a building utilizing a tankless water heater , such that hot water is available instantly at remote faucets in the building . the invention will eliminate the waste of water and heat while waiting for hot water to arrive at the outlets . a second benefit is to heat the mass of cold water known as the cold sandwich that results from the time delay for the heating element in the tankless heater to achieve its operating temperature . a third benefit is the convenience of not having to wait for hot water to arrive at remote faucets .