Yes. Any AAV can malfunction or not operate properly because it is a mechanical device. Signs of that the Sure-Vent is not operating as intended, are foul odors.
Another way is field testing in a cup of water, Place the air admittance valve (AAV) in a cup as shown below. This creates a positive pressure which seals the membrane and allows the valve to float. If the AAV sinks then most likely the membrane has been compromised which allows air to pass through the AAV and sink.
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. Remember that these valves should last anywhere from 20 to 30 years, so if they are only lasting for a couple of years, there may be some problems that need addressing.
While it's possible that it's defective, the symptoms could also be due to a clog downstream. The AAV won't deal with positive pressure, ie allow air to be pushed out (otherwise you'd get sewer gas), so if there's a clog, the air doesn't have any place to go until it slowly works it's way out.
In order for a liquid to come out, air must come in. All DWV plumbing systems require at least one vent penetration through the roof line, which allows air to enter the system, while also permitting sewer gas to escape.
Potential issues with air admittance valves
Occasionally the valve may get stuck.
This is because most air release valves seal around 25 – 30 psi unless a special soft seat is provided. So when the pipeline is filling and pressurizing, your air valve is exhausting both air and water into the exhaust pipe.
Studer vents are certified to reliably. However, anything mechanical can and will fail. Few manufacturers claim they are better for 500,000 uses (about 30 years of use). The United States manufacturers provide warranties that range from one year to a lifetime.
The other potential problem with using an AAV instead of a vent pipe is that if you ever get a blockage in the system that prevents the gasses from being pushed down into the sewer, those gases will have nowhere else to go.
The short answer is a minimum of 200mm above any water entry point. So if you imagine your soil pipe run, then durgo valve / AAV must be fitted above the highest connection to the soil pipe from any sink, bath or toilet that is connected to it.
Yes. Any AAV can malfunction or not operate properly because it is a mechanical device. Signs of that the Sure-Vent is not operating as intended, are foul odors.
AAV location
An AAV should be located within the maximum developed length permitted for the vent. It must be located a minimum of 4” above the horizontal branch drain, 6” above any insulation material and within 15 degrees of vertical.
These valves not only save space but also help keep sewer gas out of your home, promoting cleaner air. If you notice slow drains or gurgling sounds from sinks, it might mean there's negative air pressure in your drainage system, and that's the ideal time for these valves to be beneficial.
Signs of a clogged or blocked vent include gurgling sounds from drains and toilets, slow-draining fixtures, foul sewer odours around sinks and drains, decreased water pressure, and bubbles coming up through the toilet bowl. A clogged vent pipe prevents proper airflow and allows sewer gas to back into the home.
Air admittance valves are not permitted in spaces where pressure conditions adversely affect the valve's operation. They are also not allowed in concealed wall and ceiling spaces used as plenums as part of an air distribution system that is under negative or positive pressure.
Individual and branch-type AAVs shall not be located not less than 4 inches (102 mm) above the horizontal branch drain or fixture drain being vented.
Providing it is fitted correctly, there is little that can go wrong with an air admittance valve and this will be largely due to the valve malfunctioning or failing over time.
How do I know if the AAV is working? The most accurate way to test an AAV is by using a manometer. However this may not be readily available. Another way is performing a field test in a cup of water, Place the air admittance valve (AAV) in a cup as shown here, on page 4.
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.
I have had plumbers tell us that sewer flies and bugs have been seen at failed air admittance valves. So if you detect a sewer odor under and around your sink or in the attic, the AAV could have let you down.
Condensation in the Air Ducts
If these ducts are not well insulated, they may accumulate condensation on either the inside or outside. This excess water can then lead to leaks. We recommend hiring someone to insulate your ductwork or doing it yourself to prevent these issues.