Check the pressure switch -the system that determines correct water level in the drum. Its a round item about 3 inches across with several wires connected, it sits under the top cover. Its an air operated switch which tells the machine water has reached the correct level. Disconnect the thin rubber pipe from the switch and blow down through it to clear any blockage. Switch itself may be faulty but its more likely the pressure pipe is blocked.
Repair and service your own washing machine. Go to www.2ndwave.co.uk/manual.html
dannyboy, October 2008