Remove the cover at the rear bottom right as look at rear of machine it has 2 pipes going into it, it unclips then you can clean the fluff etc. from the pump and reservoir, also check the black pipe is not blocked, also move the polystyrene float gently up and down you should hear the microswitch clicking. carefully reassemble and you should be ok. Please make sure you unplug the machine from the mains before you try this
Roy
February 2011