Thanks. However, ther are two things a) I'm not using the aircon and b) I don't have a ball valve where you described it, only in the forward saloon sole compartment where there are three of them. Your boat seems a much later one than mine so maybe they added the valve in later models. I do see a pipe coming from under the freezer joining the main drain so I will check the aircon drip tray.
Ya Fohi - Amel 54 #98