NOVELTY - The heater has an exhaust gas heat exchanger (60) mounted within an asphalt storage hopper (70). A thermostatic controller (110) is connected to a temperature sensor (90) and a flow controller (30). The thermostatic controller receives a discharge signal from the sensor, processes the discharge signal from the sensor to determine temperature of contents of the hopper, and generates a control discharge signal for directing the flow controller to distribute exhaust gases to a first discharge or second discharge for achieving desired temperature for the contents of the hopper.    USE - Thermostatically controlled asphalt heater for use with a mobile self-propelled pavement repair system for heating asphalt pavement patching material such as concrete and asphalt, for a mobile pavement patching vehicle.    ADVANTAGE - The heater can vent exhaust gases from an internal combustion engine of the vehicle directly to an environment, or pass exhaust gases through the exhaust gas heat exchanger if heat is required to be applied within a hopper in operation of the flow controller so as to achieve or maintain desired temperature. The heater reduces flow to the heat exchanger if asphalt temperature is higher than desired temperature, thus allowing the asphalt to cool to the desired temperature. The heater utilizes wasted heat from engine exhaust to be used in maintaining the asphalt material in the hopper at temperature optimal for use in road repairs, and allows an operator to select temperatures over a wide range to provide patching material at temperature optimal for making road repairs.    DETAILED DESCRIPTION - The first discharge is an exhaust pipe (40). An INDEPENDENT CLAIM is also included for a method for maintaining desired temperature of an asphalt aggregate stored within an asphalt hopper of a mobile self-propelled pavement repair system.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a thermostatically controlled asphalt heater.    Flow controller (30)    Exhaust pipe (40)    Exhaust gas heat exchanger (60)    Asphalt storage hopper (70)    Temperature sensor (90)    Thermostatic controller (110)