PaulJS

In the first instance - from the trap under the bath - and we had water spitting up from the plug. We’ve since installed a waterless trap and now the gurgling comes from behind out toilet.

Thanks for writing, both. AAV is next to the stack and at the foot of our bath. It’s a McAlpine A1 AAV. Best, Paul

Advice needed: We’re the middle flat in a multi-occupancy building of three flats. There is no vent going out through the roof. There is an AAV in the bathroom in the flat above, and we have fitted an A1 AAV in our bathroom (all within the last 12 months). However, we are experiencing what I think is described in the thread above as a partial vacuum. We get considerable gurgling noises when both upstairs and downstairs flush their loo or release large amounts of water, and our waste drainage is very poor from our loo. CCTV has shown the shared stack is all clear and no problems on mains drainage. So it seems the issue (I think) is that there is no escape and vent for fowl air. Is it possible to vent (for outgoing air) from our middle flat? Has anyone experience of this? I presume were we to do this, we would need to extend external piping 900mm above upstairs’ window as per Building Regs. We already have an aperture in the external wall which vents steam from our windowless bathroom, so I’m wondering if I can use this hole in the external wall to vent outgoing fowl air. Any advice very gratefully received. Paul