Abstract: A device to control the functioning of a heat exchanger comprises an electric generator, suitable to generate an electromagnetic field, at least an emission element, connected to the electric generator and associable with the heat exchanger, to generate in the latter an electromagnetic field, at least a detection element, configured to detect a value of the electromagnetic field with respect to the value generated by the electromagnetic field, and a detector, connected to the detection element with an appropriate de-modulation and de-coding method to determine functioning conditions of the heat exchanger.