What air admittance valve means
An air admittance valve is a one way valve that lets air into a drain line when water flows, then closes to keep sewer gas in. It can stand in for some vents that would otherwise need to go through the roof.
Also called AAV, Studor vent.
Where it matters on a plumbing job
AAVs make island sinks and remodels easier, but local codes differ on where they are allowed, and they must stay accessible. Check with the inspector before you plan around one.
What the model code says
- Individual and branch air admittance valves conform to ASSE 1051, and stack type valves to ASSE 1050. (IRC 2021, Chapter 31)
Check which code edition your building department enforces for air admittance valve before you quote.
What it costs
Koira's kitchen faucet replacement cost guide puts a typical job at $280, with most between $160 to $380. The guide shows its sources and what moves the price.
Work it out
- Cost guide: Kitchen faucet replacement cost
- Licensing: Plumbing license rules by state
- Tools, templates and guides: Free plumbing resources
Sources: 2021 International Residential Code, Chapter 31, Vents (ICC). Checked October 9, 2026.