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Air Admittance Valve Problems and Solutions

An AAV sucks the air into the water pipes to fill the vacuum when the water leaves through a tap or shower. Now, the main problem related to faulty AAVs is the emission of sewage gas in the house.

The easy fix to this is to replace the faulty AAV as soon as possible. However, other problems related to AAVs can be complex and troublesome.

That’s where I come into play. In this article, I’ll guide you through all the major air admittance valve problems and solutions.

So, if you want to solve issues in your AAV quickly, stick with us right to the end!

5 Major Symptoms Of Faulty Air Admittance Valve

Air Admittance Valve Problems and Solutions

The first step to solving issues relating to AAV is to pinpoint whether or not your AAV is indeed problematic. To do that, you need to follow the symptoms we have mentioned below:

1. Unwanted Odors And Smell In The Home Atmosphere

The first and foremost symptom of a problematic AAV is that you will have a stinky smell all over your house.

More specifically, the airflow in your plumbing system will be disrupted if your AAV is not working properly. As a result, stinky air will come out of your sewage into your home atmosphere.

2. Strong And Frequent Air Admittance Valve Noises

An ideal plumbing system of a house should always be quiet. However, in case you have a problematic AAV in your plumbing system, you’ll hear frequent and loud gurgling sounds from your water outlets and toilets.

If you are indeed hearing gurgling sounds from your sewage pipelines and outlets, it indicates that airflow is somehow being disrupted. And in most cases, replacing your AAV will fix this issue.

3. Wastewater Coming Out Of Sinks And Toilets

The job of sinks and toilets in our house is to carry the wastes and wastewater away and into the underground sewage systems.

However, if you have a malfunctioning air admittance valve, you may notice that wastewater is coming out of your toilets and sinks.

4. Presence Of Sewer Gas In The Building Atmosphere

Any amount of sewer gas that is generated in the sewage system should be let out into the outdoor atmosphere through air valves.

However, sewer gas will come out of the toilets and sinks for those of you who have a faulty air admittance valve. Also, you’ll have problems breathing in your home due to the accumulation of sewer gas in the home atmosphere.

5. Air Admittance Valve Leaking Water

The function of air admittance valves is to let the air in into the plumbing system and not let the air out. That means nothing should be leaking out of the AAV (not even air).

Therefore, if you notice that your air admittance valve is leaking water, you can be 100% certain that your air admittance valve is faulty.

What Causes Faulty Air Admittance Valve? [5 Common Reasons]

There can be countless causes that are responsible for a problematic AAV. But, you’ll majorly notice the following causes for having a faulty air admittance valve:

1. Holes In The Air Admittance Valve

As we have already mentioned, an air admittance valve should never leak any air or water. That means there cannot be any hole in an air admittance valve.

Now, if you have rodents and mice in your house, they can chew into the AAV and make holes in it. If this is indeed the case for you, you’ll immediately notice that your plumbing system is not working the same anymore.

And that’s your cue to understand that your air admittance valve has been compromised.

2. A Clogged Sewer

Your sewage system’s job is to remove liquids and semi-liquid wastes. But, if you have any solid object jamming your plumbing system, you will eventually have clogged sewage. That, in turn, will generate pressure in the AAV.

Now, if this air admittance valve positive pressure remains intense for a long time, your AAV will start malfunctioning. As a result, you will have bad odors all over your house.

3. Using Air Admittance Valves For A Long Time

As we have indicated above, most manufacturers will promise that their AAV hardware will last for multiple decades. However, that is not true at all.

Rather, to have a problem-free sewage and plumbing system, you must conduct an air admittance valve replacement every 10 years of usage.

So, if your air admittance valve is older than 10 years, this might be the cause why it’s showing problems.

4. Physical Damage In The AAV

Regardless of how top-quality your air admittance valves are, they are bound to show problems if they’re physically damaged. Physical damage to the AAV can occur due to accidental physical impacts on the AAV by children or pets.

5. Faulty AAV Installation

Sometimes the problem lies in the root; the installation of the air admittance valves. Professional plumbers and sewage experts will install your AAVs with proper sealants and compatible washers. As a result, the installation done by professionals will be flawless.

However, if you attempt to install the air admittance valves without prior experience, you’ll likely end up installing the AAV in the wrong way. Resultantly, you might notice that your air admittance valves are showing problems within months of installation.

Air Admittance Valve Problems And Solutions

Air admittance valves are such hardware that needs to be fixed ASAP if they are problematic. Otherwise, you’ll end up having disgusting and stinky smells all over your house.

That’s why we have listed down below the major problems that might arise in your AAV. Plus, I have also laid down the solutions to these problems.

Note: You can use the air admittance valve diagrams below to understand its problems and solutions better.

air admittance valve diagrams image
air admittance valve diagrams

1. Air Admittance Valve Smells: Stinky Odors In The House:

If you can pinpoint that the cause of the bad odor in your house’s atmosphere is your air admittance valve, you can take the steps below to replace the AAV.

Remember, the best solution to tackling a problematic air admittance valve is to replace it with a newer one.


If you don’t have any experience whatsoever in replacing parts of the plumbing system, you should not approach to change the AAV. Rather, I recommend you call a professional plumber to do the job.

Keep in mind that the hygiene of your house atmosphere will depend on how neatly the job of replacing the AAV is done. Therefore, you should call the best plumber in your locality.

But, if you know how to change plumbing hardware, you can follow the steps below to replace your existing AAV.

A) Turn off the water supply in your plumbing system

First of all, you should turn off the water supply valves of the outlet where you will be installing the AAV. This will make sure that you can disassemble the existing AAV without spilling water all over your house.

B) Remove the air admittance valve from the sanitary t connection

In general, AAVs are installed on an AAV adapter valve, which is also installed on a sanitary T connection. Therefore, before installing the new AAV into the adapter valve, you’ll need to unthread and detach the old AAV from the AAV adapter valve.

C) Attach Teflon tape to the AAV threads

Just like any other sanitary hardware, Teflon tape must be attached to the threads in the AAV before you install it. Teflon tape will make sure that no air or water is leaking out of the threads of the AAV.

D) Thread the new AAV into the adapter valve

Once you have applied enough Teflon tape on the AAV threads, you can now use your hand to thread the AAV into the adapter valve. Mind you; the threading should be in a clockwise direction.

Now, you need to be careful at this step not to thread the AAV too much. It’s because threading the AAV too tight will cause it to rapture its threadings.

As a result, you might need to buy a new AAV. So, be cautious while you steadily thread the AAV into its adapter valve.

2. Bad Odors Even After Changing The AAV

If the bad smell is persisting in your home’s atmosphere even after replacing the old air admittance valve, you need to understand that the problem lies in the plumbing system and the sewage system of your house.


The only solution to this problem is to call in a professional plumber to check the whole plumbing system of your house. You can also tell your plumber to change the position of the air admittance valve.

Sometimes, the air admittance valves are installed at an incorrect height relative to the water outlets (sinks, toilets, etc.). If this is the case for you, the AAV will continuously show problematic behavior unless you install the AAV at the correct height.

The correct height for air admittance valve placement is 3 feet above the water outlet where the AAV is installed. So, you should tell your plumber to change the AAV location so that it is at least 3 ft above your water outlets.

3. Sewer Gas Leakage Even After Changing The AAV

As we have already indicated above, your air admittance valves will generally be installed on an adapter valve. And the adapter itself will sit on a sanitary T connector.

Now, if you have a sanitary T connector that is physically damaged, you will have air or water leaks throughout the damaged T connector. In that case, you need to follow the solution below to change the T connector ASAP.


Just like the air admittance valve, you need to be careful in changing the T connector as well. If you have no prior experience in replacing plumbing parts, you should call in a professional to do this job for you.

However, if you want to solve this problem in a DIY fashion, you can follow the steps below to change the sanitary T connector:

A) Turn off the water supply valve

The first thing that you should always do before changing any plumbing parts is to turn off the water supply valve. This will make sure that you’ll not unexpectedly get hit by the water gushing out of the pipelines when you uninstall the old T connector.

B) Unthread the valves that are securing the T connector

A T-connector has three openings on it: the AAV will be connected to one opening, your water outlet (such as the sink) will be connected to another opening, and the water supply line will be connected to the other opening.

Now, you need to unthread the T connector from the water supply line first. After that, you can unthread the T connector from your water outlet line. Lastly, you can unthread the T connector from the air admittance valve as well.

C) Apply Teflon tapes on the new T connector

In this step, you’ll need to cover the threadings of the new T connector with Teflon tapes. Applying Teflon tapes will make sure that the T connector is connected tightly to the plumbing system. As a result, no water is able to leak through the threadings.

D) Thread the T connector to the plumbing system

Now, you can thread the new T connector into the plumbing system, just like how you unthreaded the old one. You’ll need to attach the AAV in one opening, your water outlet connector in another opening, and the water supply line in the remaining opening.

And, just like that, you will be done replacing your old T connector.

When Should An AAV Be Replaced?

The general direction of changing air admittance valves is after 500,000 cycles of usage. In simpler words, the manufacturer of air admittance tells us that a single air admittance valve will last for at least 30 years.

However, in practicality, it is very rare to see an AAV last for as long as 30 years. Rather, in the case of most air admittance valves that are used in normal households, a replacement will be necessary after 10 years of usage.

However, if the air admittance valves are being used in a commercial building’s plumbing system (such as banks, hospitals, public subway stations, etc), the replacement of AAVs should be taking place every 5 years.

In addition to that, you must also check and inspect the air admittance valves of your plumbing system every month. This way, you can preemptively take a step before any problem can arise in your air admittance valves.


The final summary of this discussion is that your air admittance valves may cause problems due for various reasons. However, the universal fix to all these problems is to replace the air admittance valve with a newer one.

Or, if the problem lies in other parts of the plumbing system, you should call in a professional plumber to replace that particular component. Plus, to stay away from severe problems, always try to do routine checks on your air admittance valves.

If you can maintain these regulations, you can rest assured that your plumbing and sewage system will stay problem free for a long. Best of luck to you!