Abstract: A fixation heating circuit includes a mains power interface; a switch circuit, a heater, and a temperature detection circuit that are connected to each other to form a heating loop. The fixation heating circuit further includes a switch control circuit; a thermistor reception terminal; and a thermistor insertion terminal. The thermistor insertion terminal includes first to fourth insertion terminals, a thermistor being connected between the first and second insertion terminals, and the third and fourth insertion terminals being connected via a wire. The thermistor reception terminal includes first to fourth reception terminals corresponding to the first to fourth insertion terminals, the first and second reception terminals being arranged in the temperature detection circuit. The temperature detection circuit is connected to the switch control circuit that is connected to the third reception terminal. The switch circuit is connected to the fourth reception terminal.