If you happen to notice that your air admittance valve is acting like it is not sucking up what it should, then you may have a hole or two on your hands. Sometimes you may find that even with an air admittance valve, there are still clogs and a sewer odor. While this is rare, it is possible.

Failure to bring air back into the pipes can result in a vacuum (causing slow draining and gurgling), or even the siphoning of water out of traps (allowing sewer gases to enter the home through drain openings).

an AAV is a mechanical device. anything mechanical can and will fail. it is just a matter of time. an atmospheric vent has no moving parts.

They can go bad. They should only open up on negative pressure. Otherwise, they should remain closed so you shouldn’t get any sewer smell.

The studor vent also does not allow sewer gases out so it only lets air in and not out. They are however overused so if you can put a traditional vent in it is best to do because the studor vent does not last forever and they do go bad and need replacement from time to time.

The AAV shall be installed not less than 6 inches (152 mm) above insulation materials that may block air inlets or otherwise impair the operation of the device.

200mm
Air Admittance Valves must be installed on a soil pipe at least 200mm above the highest water entry point on the system – that is the highest point that water can normally reach in a soil pipe. For aesthetic purposes though they are usually installed in the loft or in a duct or cupboard.

The Oatey Sure-Vent AAV is sensitive to pressure changes to consistently open and close as needed by the plumbing system, closing by gravity and sealing the vent terminal at zero differential pressure (no flow conditions) and under positive internal pressures.

AAVs aren’t without their problems, however: An AAV is a mechanical device, and mechanical devices can fail. If it gets stuck in the open position, an AAV could allow sewer gases into the house. Some local codes do not allow air admittance valves.

Air Admittance Valves (aka Studor vents) are “negative-pressure-activated” one-way mechanical valves. Used most commonly at an island sink or vanity the vents are also located in the attic to prevent the roof penetrations (as seen above) on the front roof line elevation.

If you happen to notice that your air admittance valve is acting like it is not sucking up what it should, then you may have a hole or two on your hands. Sometimes you may find that even with an air admittance valve, there are still clogs and a sewer odor. While this is rare, it is possible.

An air admittance valve must always be accessible because you may have to service or replace it, so if you install it behind a sink wall, you must provide a removable access panel. The AAV must also be in a location that allows air to enter the valve, so it can’t be in an airtight enclosure.