What are air admittance valves?
The drain-waste-vent system (DWV) often employs a mechanical vent, also known as an air-admittance valve or AAV. Although they may function as intended, AAV’s are a mechanical component, and as such, they are subject to failure over time. When an AAV fails, it can lead to issues such as inadequate venting, sewer gas odor, or even …