A semielectronic control system for a combination washing and drying machine utilizing a solenoid-actuated stepping switch, each successive position of the switch controlling such functions as water fill, agitate, drain, extract, and dry making up the washer-dryer''s cycle of operation. Energization of the solenoid is controlled either by RC timer circuitry having a number of selective delays or by circuitry responsive to sensed conditions. The stepping switch selects the appropriate delay in the RC timing circuitry or the proper condition responsive circuit which causes energization of the solenoid to advance the stepping switch to the next position.