a f4 fault code means : Draining fault, which can be caused by any of these normal problems - pump, water sensor, wiring fault or pcb, i would check your pump first.
To reset appliance press and hold the start button until the light goes out, pick a different cycle and restart the programme as the pump always starts first to get rid of any water in the machine this will confirm whether the pump is faulty without stripping the appliance down.
Hope this helps - have fun
foot, June 2009