I have a similar problem with the same machine.
When I phone hotpoint service they seemed to know about this fault so I guess it is quite common. Paid in advance for hotpoint service engineer to call, who tried to unblock the drain with a length of metal rod (we had already tried that ourselves and had told them when booking the service call!) after 20 mins he said there was nothing further he could do, suggested we buy a new fridge freezer and left!
Phoned hotpoint service to complain, they would not give refund for so-called 'engineering' visit. Not happy at all with this. I suggest taping plastic drinking straws together and pushing down the hole to unblock - Do NOT call hotpoint service they will charge £90 to do nothing - a complete rip off!!!
stefan
January 2008