We have a 10 year old Ferroli Falcon II which we had installed.
Historically we've had problems like this before, last time I think it was the expansion tank needed to be pressured. We have the insurance cover with Ferroli but they now charge if the problem isn't boiler related. We currently have a call logged for Monday so hope it is boiler related!
Not sure if this is the same problem though, pressure keeps dropping and needs topping more frequently, every 10 days or so now. I haven't noticed if the copper pipe outside is leaking can't tell as it's raining so I have attached a plastic bag over the end to check it later!
If there's no water in the bag then from reading on the net it's likely to be somewhere else, can't think where, nothing on the ceilings but more worryingly some pipes are under a solid floor and others downstairs are under Karndean flooring so locating a leak would be a nightmare.
Anyone any other ideas, I think we are covered on our house insurance for water leakage but really don't want to go down that road yet....