I had this problem too and the hotpoint engineer said that the only way to get the condenser unit properly clean is to blast it in the shower - This seems to work really well, although I am having the problem again now.
I stripped the machine and found that the reservoir at the back of the machine was full of gunk, so I cleaned this out too and my machine worked for about 15 minutes and is tripping the power again.
I read somewhere that you have to use a pipe-cleaner or similar to unblock the pipes which lead to and from the condenser tray at the back...
I think that monthly cleaning of the condenser unit is not enough - weekly is better.
I reckon that because the lint filter is so rubbish I have probably got a build up of lint somewhere in the machine that gets wet and subsequently trips my whole fuse box!
Am going to have to completely disassemble blooming thing now and see if I can find anything else....
Any suggestions?
Mairifrost
March 2009