Host:

Only recently, My shower gurgles when the toilet is flushed. I read your response to a similar question with the response, "Somehow you're not venting the system. Check the AAV to be sure it's working.". I do not however, know what an AAV is (or where it is located), could you expand on this?

Larry01

Check this thread... it may answer your question..

https://www.askmehelpdesk.com/plumbing/tub-drain-gurgles-when-toilet-flushed-6821.html

Hey Larry,
You probably don't have a AAV,(Air Admittance Valve) (see image)for a vent. It's more likely you're vented by the lavatory roof vent.. This cold be iced up or be blocked by leaves or a dead critter but I would snake from the lavatory roof vent. Put out enough cable to reach the base and about 18 feet more. Good luck, tom