Abstract: A device for recovering heat from dishwashing machines, especially dishwashing machines of the type in which dishes to be washed enter the dishwashing machine through an opening in one side and are removed from the dishwashing machine from an opening in the opposite side of the machine. The device has air inlet means positioned to receive heated air from the openings in the dishwashing machine and conveys the air via duct work through a heat exchanger. The heat pump compresses coolant fluid which then flows through condenser means and then to the evaporator wherein the heat exchange with the air occurs and then back to the pump. Water undergoes heat exchange with the coolant fluid in the condenser means and this water may be used during the dishwasher cycle. Control means control the supply of coolant fluid to the evaporator and the starting and stopping of the drive motor for the pump.