Anyone ever experienced intermittent loud noise and pipe vibration coming from a gravity fed shower pump (Aqualisa Quartz A2 pump - approx 2-3 years old - but hardly used..) although the shower itself isn't being used?
I'm thinking an airlock of some sort that may clear with frequency of use?

Any ideas welcomed as it does sound like the thing is gonna blow when it happens!
Thanks

Mike, August 2009