Temperature-control system used for heating or cooling in a method for controlling temperature of a component includes connected temperature-control device, temperature-control arrangement, supply line, and return line. The system additionally has a controller having a valve, an actuator, a supply temperature sensor, and a return temperature sensor. A temperature difference between the supply temperature and the return temperature of a fluid circulating in the system is registered using the supply temperature sensor and the return temperature sensor and also a regulator. Proceeding from this temperature difference, the regulator causes the actuator to set a degree of opening of the valve so the temperature difference is in a selected value range. The valve always has a minimal degree of opening in the open state.