During the past decade, heat pumps have proved to be a more effective means of reducing h e a t i n g costs than conventional ele ct r i c systems. Although there is general agreement on the potential cost savings of a heat pump , a number of questions have been r a i s e d concerning what savings might be realized through thermostat setback at night. T h i s study examines an improved control method applied to the thermostat, which maximizes the use of the heat pump and minimizes the use of resistance heaters during the recovery period. This method also anticipates the recovery start time to insure that the comfort set point is reached at the desired time.