Disconnect the machine from the supply (water and power) and drain.
Remove the cover (about 5 screws) at the back of the machine that goes around the dain pipe.
You will see a black rubber boot, about 3 inches diameter, that connects from the bottom of a white plastic bowl to the outlet pump (in the lower right corner) and a second white plastic pipe. Undo the jubilee clip and drop the black rubber boot down to expose the filter; it can easily get blocked by a small item of clothing or stuff you may have left in your pockets!
FixedIt, June 2010