yes I do have a delay timer.
What is happening is - I switch machine on - programme for normal wash light flashes (153) is seen in display. I shut dishwasher door and immediately it bleeps a short bleep and nothing happens. Sometimes though, on doing the same I open the door and no display lights are on at all but you can hear faint short beeps coming from the machine.
I have cleaned out the filter area and soaked up all excess water. I switch on and it seems to start but seconds later stops and bleeps once - I open the door and it is still set for normal wash.
the dishwasher was installed before we bought the house so I am trying to get hold of the builders to find out who they got the d washer from.