any ideas what is wrong with my Bosch WFF 2001 GB?

It keeps cutting out the RCD to the house. This seems to happen when it has taken some water in, if it gets that far that is. To try and start the washing machine again makes it cut out immediately. However I then left it for 3 days and managed to do 2 washes until the same problem happened again. I have tried different wash cycles. Has anyone got any ideas of the cause please!