maillemaker wrote:
What is an "AAV"?
Steve
An Air Admittance Valve is necessary under the cabinet holding a sink unless that sink's drain line is connected to the roof vent. Without some kind of air admittance vent, the suction of the water going down the drain would pull all of the water out of the sink's trap, allowing sewer odors to come up. The AAV breaks that suction. It is a one way valve, allowing air to go into the drain line, but not allowing air (odors) to come back out. If the AAV fails open, it allows air (odors) to come out. If the AAV fails closed, it sucks the water out of the sink's trap allowing air (odors) to come out. The solution for either condition is to replace the AAV. It is cheap and easy. It costs less than $10 at a big box hardware store, and just screws on.
