Abstract: A peak load control apparatus with operating mode selection for an electric heating system having a plurality of electric heating units arranged in two or more groups in different rooms is disclosed. When the current carried by the feeder line exceeds a predetermined value a peak load trigger or flip-flop which receives a signal proportional to the feeder current from a detector delivers a peak load signal to a first control circuit or monostable which cuts power to a first selected group of heating units for a predetermined period, and to a second time control circuit or monostable which cuts power to a second selected group of heating substantially at the end of the period during which power is cut off to the first group of heating units. The heating units are provided with programmable thermostats connected to operating mode selector switches which are connected to the feeder line.