F4 is a drain pump fault. Turn off at the mains and drain water out of dishwasher
Remove the lower front cover and you will see a pump on the left of the drain, disconnect the electric plug, disengage the clips either side of the magnet and slide it off. This will allow you to twist the pump about 30 degrees anti clockwise and remove it. Slide the components apart clean and check inside the sump for any foreign bodies ( found a piece of glass in mine). put back together in reverse order ensuring seals are on. Put about a pint of water back in and turn on. If code reappears turn off then turn on again. Try reset by holding down programme button.
terry, February 2008
