: I'm sorry, can you explain what a AAV is??

: I am pretty much a layman when it comes to plumbing.

: Thank you in advance,
: HArvey

Reply:
It's a quick vent, cheater vent, mechanical vent, basically it's just a short cut not to have to install typical atmosheric vent line, the preferred method among many licensed plumbers. As Deb mentioned, they're not allowed in certain areas according to local plumbing code.
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