I had the same problems a couple of years ago. The door wont open if there is still water in the machine. It may look empty but it is not. Check the pump is not blocked, one way to do this is to take off the hose from the drum make sure you have a receptacle to catch the water that will come out. Once you have done that you can release the pumps exit hose, then unscrew the pump bracket remove the wires noting the correct way round. if you cannot for some reason disassemble the pump you can reverse flush it
if the fins rotate freely inside the pump there is no blockage. next check that the ball inside the outlet orifice from the machine is free to move up and down if this ball is stuck closed then water cannot flow from the drum to the pump therefore water is still in the machine I would also check the filter once there is no more water in the machine the door latch will release.
David Alcock, June 2010
