Abstract: A thermostat control for a heat pump thermostat allows the heat pump to change its temperature setting automatically and systematically minimizing the use of resistive heating with the heat pump as a backup to accomplish the temperature change. A cam having a smooth and gradually varying cam surface changes the position of the thermostat control on the heat pump thermostat to move the control through a desired temperature differential at a rate less than the rate at which resistive heating will be used as a backup to aid the change unless the heat pump is operating at full capacity.