Abstract: A device for controlling the heating of a hot water boiler includes a first temperature sensor sensing the temperature of the boiler liquid and operating means adapted to switch a control switch. It also includes an outside temperature sensor to be arranged elsewhere and comprising a liquid-filled reservoir which communicates via a capillary with a tubular coil spring of the control device, which spring also actuates means which are adapted to switch the first switch. The tubular coil spring is arranged to actuate with an outer winding means adapted to change, through this actuation, the relative position of elements of the control switch and hence the temperature at which the control switch is switched under the control of the first temperature sensor.