Tom, the air connections may have become disconnected. This happened to me. If you can take the facia off it should be obvious. I have another problem, my water tank inlet valve in the loft got blocked and the tank ran dry. Now the Grohe cistern is dry. I suspect either an air blockage or that you have to have water in the system to make it work. Does anyone know?
Kevin, Wokingham, May 2009
