Abstract: A hot water distribution system for providing almost instantaneous supply of hot water at a hot water usage outlet. The system of the invention comprises a closed loop and a pump circulating hot water in the closed loop from a supply of hot water and back to the supply of hot water. One or more usage outlets are connected to the closed loop each by a relatively short length of pipe. A one-way check valve prevents drawing water from the return line of the closed loop. Heat insulation of the closed loop is provided to prevent unnecessary heat losses, and a thermally operated switch may be used to control the operation of the closed loop circulation pump to maintain the water in the closed loop at a predetermined temperature.