A defrost control system includes in an electrical control circuit, a number of relay coils and contacts responsive thereto for insuring a delay in termination of the defrost mode and reverse refrigerant flow to the outdoor coil of the heat pump system to delay coil operation as an evaporator, and to effect automatically fan motor reversal and energization to blow air downwardly over the outdoor coil fins to assist gravity in removing the condensate during delay in initiation of heat pump heating cycle, thereby preventing refreezing of condensate on the coil fins.