Abstract: A water and energy conserving apparatus for supplying pre-heated water to a hot water heater and for cooling at least one refrigeration unit using a compressible medium in a food serving establishment comprising, a pre-heater tank adapted to receive water from a cold water source and having a cold water inlet line connected to the cold water source and a cold water outlet line. A heat exchanger which is associated with the refrigeration unit is connected to the cold water output line coming from the tank. A hot water output line is connected between the heat exchanger and the tank for returning water from the heat exchanger to the tank. The compressible medium which is hot is supplied from the refrigeration unit to the heat exchanger and the water flowing through the heat exchanger cools the compressible medium thus picking up heat. A circulator is connected into the hot water output line for circulating water from the tank to the heat exchanger and back.