how to fix zanussi zwd122704?

hi
my zanussi zwd12270w does its 40dg wash and before it starts to rinse stops clicks to open door and goes back to the start of the programme it will not let you use any other programme for at least 2hours.I have tried doing a cold wash and also a 30dg wash and both times it went all the way through its programme it only seems to have this problem on hotter washes any help please