There is no way to get the AAV in kitchen cabinet of old old home? What will happen if it is installed into KS drain line in the basement? Manufactuer says it needs to be 4 in. above trap. What if it is not? Is this to to prevent leaks if line gets plugged or does it have to do with siphoning the P trap dry? Or is it supposed to be 4 in. above for some other reason?

Thanks
Scott

It won't work and it will not be code, other than that its fine. It is designed to allow air into the drain pipe an not siphon water from traps.

I understand it will not be code, but what won't work about it?

And also I undrstand it lets air into the pipe. To clarify my question, will it work even though it is below the trap. (Ptrap into horizontal pipe in wall, then vertical then back to horizontal where I would like to install the AAV into a T fitting on its back

Hi Scott...

An AAV is installed at a minimum of 4" above the PTRAP because it is meant to introduce air into the system at a level that allows waste water to mix with the air to create a self-scouring/cleaning effect on the ptrap and the pipes. If you install the AAV below the trap then the trap will not get the air that allows the waste water to self scour the trap/pipes.

It does not guarantee a clog, but a clog is much less likely if you install an appropriate vent in the correct place... ;)

MARK

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