There might be something blocking the pump.
You can tell by the fact that it makes a noise as if it wants to pump but still it doesn't - a low humming.
1) Remove the plug.
2)Open the white lid in the lower right corner.
3)Unscrew the filter and take it out. (have a towel and bucket ready: ALL the water will be comming out).
4) Reach inside with your hand you'll feel a small wheel that must be able to turn around freely. Do'nt worry to put your hand in you have unplugged (I hope)
I had a screw (left in one of my pockets) blocking it.
5)Now you're filter is out, clean it.
6)Screw it back in place.
7) Place the lid.
8) Plug in.
9) Have another go.
PS: This is described in the manual under 'cleaning the filter'
Andris from Belgium, November 2005