Abstract: A heating device having a thermal store provided with an electrical heater has said heater controlled by a charge control circuit which includes a programme generator delivering an output signal in the form of a programme corresponding to a load balancing condition and includes a state of charge sensor which delivers a state of charge signal compared with the programme in a comparator. The heater for the store comprises a plurality of heating elements, the number of which brought into operation to charge the store is controlled by a weather signal provided by an outside temperature sensor. Preferably the comparator provides a delay from the beginning of the off-peak period before energization of the heater starts.