I live in HongKong in one of those 32 stories apartment buildings.
Have "Silentrap" P-trap with Air Admittance valve install under the kitchen sink.
Lately sewage water leaks from the Air in-take of the AAV when water drains.
Local plumbers advised just to seal the valve with silicone. Shall I?
No code whatsoever in HongKong to govern installation of AAV in apartment buildings.