Gurgling noise coming from sink drain

[Annahmed]

Hi all!

Has anyone ever experienced a gurgling noise coming from a sink drain when using the shower? The shower drains fine, but the sink on the other side of the wall makes a weird gurgling sound during use. What could cause this, and what are some possible solutions?

[TinyTool]

Hey! That gurgling noise usually happens because of air being pulled through the sink drain when the shower is draining. It’s often a sign of a venting issue, like a clogged or improperly installed vent pipe.

Have you noticed any slow draining in the sink or shower, or is it just the noise? If it’s a venting problem, adding an air admittance valve (AAV) or clearing a blockage in the vent stack might help. Let me know if you’ve checked anything yet, I’d be curious to see what’s going on!

[Annahmed]

Thanks for the insight! I haven’t noticed any slow draining in the sink or shower, just the gurgling noise when the shower drains. I haven’t checked the vent stack yet.

If it’s a venting problem, adding an air admittance valve (AAV) or clearing a blockage in the vent stack might help.

Could you explain a bit more about how an air admittance valve (AAV) works and where it might be installed? I’m curious if that could be an easier solution.

[TinyTool]

An air admittance valve (AAV) is like a little helper for your plumbing system when venting issues come up. It’s a one-way valve that lets air into the pipes when water drains, which helps balance the pressure and prevents that annoying gurgling sound. The best part? It doesn’t let sewer gases escape into your home because it stays closed when not in use.

As for where it’s installed, it’s usually placed on the sink’s drain pipe, above the trap but below the level of the fixture. It can also be tucked inside a cabinet or behind an access panel, as long as there’s good airflow around it. If your vent stack is blocked or tricky to access, an AAV can be a much simpler fix compared to tearing apart walls to deal with vent pipes.

It might be worth trying if the gurgling is from poor venting and you don’t want to mess with the main stack just yet! Have you noticed if the noise happens only during heavy water use or every time you shower? That could help confirm if venting is the culprit.

[Annahmed]

The gurgling does seem to happen mostly when we’re using a lot of water, like during showers or when multiple fixtures are running. Sounds like it could definitely be a venting issue.

Do you think installing an AAV is something I could handle myself, or would I need a pro for that?

[TinyTool]

It definitely sounds like a venting issue, especially with multiple fixtures running. Installing an AAV could help resolve that. Basically, you’d need to cut into the drain line and install the valve where the vent should be. It’s a relatively straightforward fix, but it does require working with plumbing.

Do you feel comfortable handling some basic plumbing for this, or would you prefer to have a pro do it? Let me know, and I can walk you through the steps if you want to give it a try!

[Annahmed]

I’d love to know the process, even though I’m probably not going to do the work myself. I’m just looking to understand it better for the knowledge.

[TinyTool]

Sure! Here’s a detailed explanation of how an Air Admittance Valve (AAV) can be installed to fix gurgling noises caused by venting issues:

1. Understand the Problem
   Gurgling noises often happen because air isn’t entering your plumbing system fast enough when water flows through the pipes. Without proper venting, a vacuum forms, slowing drainage and causing the noise. An AAV solves this by letting air in without allowing sewer gases to escape.
2. Gather the Materials
   • Air Admittance Valve (sized for your pipe system).
   • PVC pipe and fittings (e.g., tees, couplings).
   • PVC pipe cutter or hacksaw.
   • PVC primer and cement (to bond pipe and fittings).
   • Tape measure and marker.
3. Choose the Installation Spot
   Identify the location in your drain line closest to the gurgling fixture (e.g., a sink or washer). The AAV should be installed on a vertical pipe, above the level of the fixture's drain.
4. Turn Off Water Supply
   Before cutting into the pipe, ensure the water supply is off to avoid any accidental flooding.
5. Cut Into the Pipe
   Use a pipe cutter or hacksaw to make a clean cut into the vertical section of the drain pipe where the AAV will be installed.
   • Remove a section of the pipe to make room for a tee fitting.
   • Deburr the edges (smooth them out) with sandpaper for a tight seal.
6. Attach the Tee Fitting
   • Dry fit the tee into the pipe to ensure it fits correctly.
   • Apply PVC primer to the pipe ends and the inside of the tee.
   • Use PVC cement to securely attach the tee to the pipe.
7. Install the AAV
   • Screw or press the AAV onto the top of the tee fitting.
   • Ensure the valve is upright and not tilted. This positioning is crucial for the valve to function properly.
8. Test the System
   • Turn the water back on and run water through the gurgling fixture.
   • Check for leaks around the new connections.
   • Listen for the absence of gurgling noises. The AAV should eliminate the vacuum effect, allowing water to drain smoothly.
9. Secure and Cover
   If the AAV is in an exposed area, it’s good to ensure it’s supported and, if possible, enclosed in a vent box to protect it. If installed in a cabinet, it must remain accessible for future maintenance.

[Annahmed]

Thank you, TinyTool.