(1) partly  blocked  filler pipe leading   into  the drum, (undissolved /accumulated powder )
 (2)filler holes partly blocked up  with (mould) causing water to spray any where missing the filler tray 
(3) excessive water pressure ,
1 put a kettle fairly HOT water into tray draw to try and dissolve powder.
2 clean holes hot water and old tooth brush
3 reduce water pressure  at incoming stopcock
                
 wirecutterman
                
 January 2008