The suspect list and it's short.
1: Dirty switch. YES the control switch may be dirty. If this is NOT the case the pump will run but no movement.
2: failed valve or valve magnet (Solenoid)
Now to test the valve you need a flat piece of metal NOT SHARP which a magnet attracts (Test) a kitchen knife may work well.
Hold it about 1/8 to 1/4 inch flat to the magnet while someone hits the switch, OBSERVE (A working magnet should attract but a well shielded one may not)
Observe if possible the valve if it's not enclosed.
From there on you got to figure out WHY it's not working.