This happened a few times to us i.e. water reservoir full warning light comes on even though we've emptied it. It seems that even though the reservoir is empty there still can be some water in the pipe leading to the reservoir. We used to leave it about half an hour or so for the water to drain, as evidenced by more water appearing in the previously emptied reservoir, the machine would then spring into life!
More recently we've found that if you empty the reservoir immediately after each drying cycle the water is allowed to drain between usage and we haven't experienced the problem of late.
David Allen, January 2010
