Here Are The Popular Air Admittance Valve Problems

Air Admittance Valve (AAV) is a mechanical valve favored by professional plumbers because they’re very flexible in installing plumbing fixtures.

The valve is fitted locally to allow adequate venting without using a larger venting system and stack vent.

AAVs are cost-effective, as they can significantly reduce the number of venting materials required in a plumbing system. However, do air admittance valves develop problems? Yes, AAVs do!

This article analyses the problems and solutions of AAVs. Are you even wondering why you need the AAVs and how they work? You’ll find answers to your questions and many more here. Read on!

Common Problems Of Air Admittance Valve 

Unwanted smells, gurgling sounds, and wastewater coming up from the soil pipes into the sink are all potential problems of AAVs.

Although these valves are framed for their toughness, leakages from holes are possible. In addition, these valves can be chewed by rats and mice, resulting in gaps. Another problem could be that the air admittance valve is installed too low or incorrectly to the vent pipes.

Sometimes, the valve may become stuck, or the waste pipe could be clogged. In these cases, gases would be pushed down the sewer, preventing water from draining away. Clogged valve is primarily due to improper valve installation.

Solutions To Air Admittance Valve Problems

Problems with air admittance valves can be irritating. However, it’s easy to fix any AAV problems if you follow the DIY steps below.

Holes in the valve:

This is the most common problem with air valves. Being cautious is the most effective technique to avoid having gaps in your air admittance valve.

The first solution is to ensure that your home is free of rats and mice. Then, you can use pests control in the house to remove any insects or small animals that could chew your air admittance valve.

You can also close the holes in the AAVs temporarily with duct tape. Finally, you can consult plumbing experts about repairing the holes before further damage occurs fully.

Clogged Valve:

To start clearing the clogged valve or drainage system, you need to check if your valve is a new fitting. In this situation, you’ll have to contact the retailer because the installation could be faulty. They would fix it or replace the entire valve system for free.

Secondly, if the air valve emits foul odors, don’t replace the pipe immediately because it has begun to deteriorate. Firstly, remove the air admittance and wait until all the air is properly expelled. This process will allow water to flow freely and unclog the entire valve.

Wrong installation:

To solve this issue, you need to double-check the vent’s installation location. Then find the suitable air admittance vent and inspect for any damaged parts.

Always remember to repair the air admittance valve as soon as possible before reinstalling it in the right vent. Afterward, open the incorrect vent and insert the pipe into the correct one.

Finally, replace all valve parts, tighten the lid and double-check that the installation is complete.

Why You Need An Air Admittance Valve

Flexible plumbing options:

AAV is a great alternative if you can’t connect to an existing venting system due to a complex pipe layout or obstructions.

The vent balances the air pressure inside the drain system. In addition, venting removes unpleasant and harmful gases from the system.

Air admittance valves allow wastewater to drain properly from a building by ventilating the earth and waste pipes. Without ventilation, air pressure fluctuations inside the pipework could cause waste traps to lose their water seals, resulting in foul odors.

Inside the roof area, air admittance valves give a more aesthetically beautiful alternative to open stacks while supplying the same level of ventilation. In other words, AAVs give plumbers and homeowners various design options for the plumbing system.

Economic purposes:

Because of these factors, an AAV needs less human resources and materials than running vent pipes in new building applications, making it a more inexpensive option.

Prevents roof leakage:

AAVs open and close with the original pipe work, eliminating the need for double roof penetration.

Many homeowners prefer not to vent through the roofline for design and aesthetic reasons. Furthermore, these fewer roof penetrations reduce the chance of leaks over time.

How An Air Admittance Valve Work

Gravity controls the operation of air admission valves. When water and waste go down a drain line, negative air pressure builds up inside the pipe. Negative pressure raises the sealing washer and allows air to enter, draining wastewater.

When there is a pressure drop, the valve opens to allow air into the pipe. The valve closes after the pressure balance is restored. This balance allows air to be sucked in when needed while keeping unpleasant odors out of the house.

Air admittance valves are often fitted with a push-fit joint. This fitting eliminates the need for tools when connecting pipes and sockets. In addition, push-fit joints have a rubber seal that makes the joint completely watertight and airtight.

Manufacturers often create a complete seal using rubber seals on air admittance valves. The rubber seals enhance the valve’s efficacy and prevent odors from escaping via tiny gaps.

The Best Place To Consider Installing Air Admittance

Air admittance valves are usually installed on a soil pipe between a fixture’s P-trap and the drain line. The soil pipe is generally at least 200mm above the maximum water entry point – that is, the highest point within the soil pipe that wastewater will reach.

They’re often attached to one leg of a sanitary tank, with the other leg leading to the drain. However, you need to follow local codes and the manufacturer’s instructions when installing the unit.

Furthermore, air admittance valves are usually installed within closets or cupboards to avoid becoming nuisances. However, it would be best to place the AAV in an area with enough ventilation.

In addition, always remember to install your air admittance valves in an easily accessible location for easy replacement, repair, or maintenance.

Can You Install Air Admittance Outside The House?

Yes, you can install an air admittance valve outside your building, but they are not common. Although most air admittance valves are best installed inside the house, some are designed outside.

You should install your AAV externally if the soil pipe is close to an opening window at least 3 meters away.

If you’re going to place an air admittance valve outside, you’ll need one that can withstand snow and not be affected by extreme weather. In addition, you should fit air admittance valves inside the building unless they are indicated as being for external use.

What Is The Perfect Height For Air Admittance?

Air Admittance Valves must be located at least 200mm above the system’s maximum water entry point. This level is the highest point water may ordinarily reach in a soil pipe.

An AAV should be located inside the vent’s maximum developed length limit. It must be at least 4″ above the horizontal branch drain, 6″ above any insulation material, and at a 15-degree angle to the vertical.

Features Of An Air Admittance Valve

Air Admittance Valves come in different sizes, materials, and colors. The valve sizes depend on the drainage capacity of the plumbing system.

They’re simple assembly valves with a small device on top, and the manufacturers determine the valve’s design and capacity.

To build high-quality valves, most manufacturers use sophisticated plastic materials. A screen on some of them can keep insects from creeping into and out of sewers. As a result, nothing but air can enter or exit the vent.

Which Valve Is Best For My Plumbing System?

You can easily figure out what valve size you’ll need in your home. In addition, you can determine the amount of waste fluid released per second by your system, as well as the pressure value required for waste realization.

Mini valves have a flow rate of 119 US GPM (7.5 l/s) at -250 Pa, while maxi valves have a flow rate of 507 US GPM (32 l/s) at -250 Pa. Remember that 10 Pa is the same as 0.04 inches (1 mm) of water gauge.

Most valves will work in temperatures ranging from -4 degrees Fahrenheit (-20 degrees Celsius) to 140 degrees Fahrenheit (60 degrees Celsius). However, the temperature range depends on the valve model you purchase.

Is The Air Admittance Valve A Dependable Device?

Many people doubt the efficiency of the Air Admittance Valve. They think that sewer waste can escape the AAV in the event of an obstruction in the drain pipes. However, experts have confirmed the device’s reliability after numerous tests for leaks and over-flooding.

A typical air Admittance valve is a high-quality, safe, and reliable vent solution that won’t cause a mess or leak. This modern plumbing device will function flawlessly in dual flush toilets, bathtub drains, and gravity-fed flushing toilets.


An air admittance valve (AAV) is an excellent way to solve venting issues while building a new house or renovating an old one. Unfortunately, these AAVs are common to develop problems due to prolonged usage, wrong installation, holes, or clogged valves.

However, this article already provided detailed solutions to your AAVs problems at home. You don’t need to waste money contracting a plumber when you can do it yourself. Just gather your simple tools and get to work!

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