Originally Posted by stevenray
I have recently installed a wall mounted lavi made in Brazil by Decca. It is a large rectangle with only a 5/8" drain hole in the front edge. The waste is intended to drain through the small hole and into the trap through the interior of the ceramic void within the sink. The drain system is attached with a 1 1/4" o-ring compression device. I have since drilled a vent hole above the drain with no success and installed a AAV after the bottle trap with still no change. I thought I had seen a tail piece replacement with an AAV at the connection but I can't seem to find it again. It was on a UK site. Any help with this persistent problem would be greatly appreciated!