I'm adding a bathroom in my house and preparing for my rough-in inspection which will involve plugging the main waste line and filling everything with water to test for leaks. I'm using an air admittance valve (AAV) for the bathroom lav instead of a vent out the roof.

Before I fill the DWV system with water, should I remove the AAV and cap off the opening? Or is it fine to leave the AAV installed for the test? It's unclear to me if the AAV is designed to prevent water from gushing out of it. I'm trying to avoid flooding my house with water! Thanks!

  • I have had them stick open but new it should work, if the valve is low on the plumbing that could allow it to collect stuff and be a problem in the future. I normally put AAV’s higher than anything that I would be leak checking, ie above the bottom of the sink drain normally. – Ed Beal Mar 25 at 16:04

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