Quote: (Originally Posted by Pierre Farrugia)
No standard unit and with Shut off valve on ADV
Make sure you have the AVD shut off in closed position. If that does not help just check by listening where the leak could be. On my unit it is 99% of times on one of the shoulder t-piece to hose connections. The other times it has been the original mouthpiece inside o-ring or the manual add buttons have been too loose.
Hope this helps!
JH