Thanks 

Hi DC it's defo the small filter adjacent the water bottle. Pull the connecting pipes off (they are tight) then wash all the gunk out of the filter using bleach / water / reverse flush. Mine went last w/e. Now if only I can get the rear washers to work ! Allen

Washer 

Hey, Wints... Thanks for the advice. I have managed to get the filter and wash it out, as suggested. The washers work great now. Thanks again.