have you cleaned the condenser unit? it is behind the panel at the bottom left hand corner of the machine. pop the flap down with a coin or screwdriver, twist the two blue catches to remove plastic cover . this will expose condenser unit which is also held in with same type clips. twist these and slide condenser out. then clean unit under a tap to remove lint. shake dry and replace.this shold cure your problem.
andy, January 2011