How to Vent a Toilet Without a Vent Using Air Admittance Valve

Written by

Paulk Webb


Freddie J. Hagopian

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how to vent a toilet without a vent

Why does a toilet need to be vented, you ask?

When water rushes down the pipes, it creates a suction effect. Without a proper venting system, this suction can slow the flow, lead to gurgling sounds, and, worst, suck out the water from nearby traps, releasing foul odors into your home. Yikes!

Is your toilet not vented? No need to fret. Learn how to vent a toilet without a vent here.

What’s the Alternative Way to Vent a Toilet Without a Vent?

For starters, it’s appropriate that you consult with your local building codes regarding your plumbing system before you choose which method is right for your home.

Indeed, there are several toilet venting options available, even without going through the roof.

In case of a ventless toilet, a common fix is an air admittance valve, also known as a cheater vent. It serves as an alternative to a vent stack.

How to Install an Air Admittance Valve (AAV)

Step 1: Prepare



  • Air admittance valve (AAV)
  • PVC pipes
  • PVC fittings (sanitary tee, couplings, etc.)
  • PVC primer
  • PVC cement
  • Teflon tape



  • PVC pipe cutter or hacksaw
  • Measuring tape
  • Marker
  • Pipe wrench
  • Screwdriver

Step 2: Determine the location for installing the AAV


You’ll have to first understand how Air Admittance Valves work.

AAVs use the force of gravity to open and close, allowing air to enter when needed to facilitate drainage and sealing shut afterward to maintain the integrity of the plumbing system.

To vent a toilet without a traditional vent, locate a suitable location to install the AAV near the toilet. The AAV should be positioned higher than the highest point of the trap.

Step 3: Install the PVC drain line


Install the PVC drain line from the toilet’s flange to the main drain line, ensuring proper slope for effective drainage.

Then, use a sanitary tee to connect the toilet’s drain pipe to the PVC drain line. The tee should have one inlet for the toilet drain pipe and another for the AAV.

Step 4: Install the AAV


Compared to other venting solutions, AAVs are relatively easier to install.

Determine the appropriate coupling (glued or threaded) for the AAV based on the manufacturer’s instructions.

Attach the AAV to the inlet of the sanitary tee designated for the AAV connection, following the manufacturer’s guidelines for installation.

Step 5: Test the installation

Ensure that the installation complies with local codes and regulations.

The AAV should be installed vertically and positioned to allow unobstructed airflow. Confirm that the AAV is securely attached and properly sealed to the sanitary tee.

Run water in the toilet and flush to check for proper drainage. Observe if the AAV opens to allow air into the system during flushing.

Frequently Asked Questions


Is it Possible to Build a Self-venting Toilet?

There are no actual self-venting toilets that completely eliminate the need for venting. Self-venting toilets are designed to eliminate the need for a traditional vent stack or air admittance valve (AAV) by incorporating built-in venting mechanisms.

However, this setup requires careful engineering and design to ensure proper functionality. You must check with your local building codes to ensure compliance with venting requirements.

What is a Studor Vent?

This type of AAV is a mechanical valve used for local venting of plumbing fixtures.

The Studor vent is typically installed near a plumbing fixture, such as a sink, toilet, or shower. It allows air to enter the drainage system when needed, equalizing the pressure and preventing negative pressure from impeding proper drainage and causing issues like slow drainage or gurgling noises.

How to Vent a Toilet with NO Outside Access?

When you don’t have access to the outside for venting a bathroom, there are several options available to achieve proper ventilation.

Some options include installing a ceiling vent, using a floor duct vent, venting through the joist cavity, and installing a bath fan.

Remember that it is better to consult professionals to determine the best solution for you and your home.


Toilet drain venting is key to a functional plumbing system.

There are alternative toilet venting methods you can try but make sure you comply with the building codes and regulations in your locality.

Now that you understand how AAV works, you can follow our simple and handy guide on how to vent a toilet without a vent using an air admittance valve. It’s time you ensure proper drainage and say goodbye to common toilet-related issues.

Give it a try, and share your feedback with us!

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