How to vent a p trap with an air admittance valve.

[@terrenceludwig5248]

I know this is for demonstration purposes only, but depending on your local codes, I think that trap arm has to be a minimum of 12” from the drain stack. It is important to mention, if cut any sorter, you can turn that p-trap into an s-trap, sucking the water in the p-trap out and preventing it from doing its job.

[@jacksplumbingvideos7147]

@@terrenceludwig5248 the requirement is that the trap arm is twice as long as the size of pipe, so a 1 1/2 trap would require a 3 inch trap arm and a 2 inch trap would require a 4 inch trap arm. A 12 inch trap arm for 1 1/2 pipe would be impossible in most cases so I have no idea where that came from, it would only make sense if it was a six inch trap.

[@terrenceludwig5248]

@@jacksplumbingvideos7147You are correct, my mistake. I just knew there was minimum and it looked close to me. But with what you said, that distance in the video is correct.

[@briancrandall1601]

I found a vintage in package Genova aav at Habitat restore.

[@jacksplumbingvideos7147]

I like those Genova nova vents as they have simple components but they stopped making them a few years ago.

[@rickywinthrop]

Never use a cheap air admittance valve. They get gummed up by condensation and when they fail they tend to fail open and allow sewer stench into your home. Spend money on a good one.

[@granitfog]

Is that a T or a Wye that is the intersection of the AAV / waste line and the P trap ?

[@jacksplumbingvideos7147]

Tee, never use a wye oriented like that as it can vacuum out the trap.

[@robertmurphy3014]

Did they complain of sewer gas ? Was that the service call?

[@jacksplumbingvideos7147]

This is a setup I built in my basement.