Disclosed is a heating device, including a first and second ends of an indoor water supply pipe communicated with a main water supply pipe and a water supply end of a radiator; a valve, a first temperature sensor, a heating and control module and a third temperature sensor arranged between the first and second ends; two ends of the heating and control module connected with a bypass pipe; a first and second ends of an indoor return water pipe communicated with a main return water pipe and a return water end of the radiator; a three-way valve and a second temperature sensor arranged between the first end and the second end of the indoor return water pipe; and a first and second ends of the water pump communicated with a third end of the three-way valve and the indoor water supply pipe.