Why Does The Kitchen Sink Gurgle When The Toilet Is Flushed?

Clogs in the Sink Drain

Both a partially and a completely blocked drain can lead to a gurgling sound, foul odors, and/or bad drainage.It's pretty simple to figure out how bad your predicament is.

Partially Blocked DRAIN

If the water level in your sink has a slow-moving drain, this is a good indicator that it is only partially blocked.You can survive with a drain in this condition for some time, your sink will just drain slowly. However, it is best to get these issues resolved before they become emergencies.

Completely Blocked DRAIN

If your water level doesn't go down, you probably have a completely blocked sewer line and it is past time to get the issue resolved.Drain cleaners are an option for you when you find yourself in this situation, however, use caution and follow the instructions carefully. If used incorrectly, these cleaners can damage your drainage pipe if used incorrectly.

Blocked Vent System

A blocked vent system can definitely cause a gurgling kitchen sink. The vents play a critical role by allowing vent air into the plumbing lines.If your air vents are blocked, the air pressure in your plumbing system will be off, which will lead to all kinds of problems.

Issues With the Air Admittance Valve

Your air admittance valve, also known as the Studor vent, is what allows air to enter plumbing systems, but it also prevents sewer gas from escaping.Leaks can allow you to smell sewage or hear gurgling noises, while mechanical failure can lead it to remain closed, causing slow drainage and a gurgling sink.Getting your air admittance valve installed by a professional plumber can help prevent some of these issues.

Blocked Sewer Line

All your drainage pipes connect to the main sewer line. If your sewer lines are blocked, they will no longer drain waste and they will back up everything connected.You will especially notice this problem when the toilet is flushed because the pressure from the clog will lead to those pesky sink gurgles... not to mention the smells.

How the Plumbing System Works

Role of Vent Pipes in the Plumbing System

This is not a complicated concept. Simply put, it is a pipe that runs from your plumbing system to a roof vent.A vent pipe will prevent sewer gas from entering your home by giving it a place to exit the system without building up air pressure or finding a place to leak.

How Air Admittance Valves Work

The purpose of this device is to equalize the air pressure within the drain line.When water is flowing, it creates a vacuum effect that can slow or stop the flow of water. The valve is installed so that won't happen.When water is flowing through the drain, the valve opens to pull air inside. However, when the flow stops, the valve closes, preventing sewer gasses from entering the home.Air admittance valves are usually installed under sinks or in other locations that are easily accessed. They are a popular option for a modern plumbing system since vent pipes can sometimes be difficult or costly to install.It's important to ensure proper installation on the front end of things, otherwise, you could run into a slew of problems.

Solution of Kitchen Sink Gurgle Problem

Clearing the Sink Drain

If the reason behind your sink gurgle is a blocked drain, it could be an easy fix. Beneath your sink is what's known as a P-trap.A P-trap is a U-shaped piece of plumbing used to create a water seal, preventing odors from entering your home.Unfortunately, it can also hold enough debris to stop your sink from draining water which will lead to a gurgling noise at best, and zero drainage at worse.You can clear the P-trap by placing a bowl beneath it and removing it from the other pipes.Please be aware that there will be water in the P-trap even if there is nothing else. Dump the contents into the bowl and replace the pipe.If the sink drains again and the sound is gone, your water seal should be restored and the problem fixed.

Clearing the Vent Pipe

Unfortunately, no amount of clearing out your drains will fix your problem if your vent pipe is blocked.You can check by having someone inside your house flush the toilet while you hold your hand over the pipe. If you don't feel suction when the toilet flushes, that means the pipe is, indeed, blocked.Also, unfortunately, your outside roof vent can be hard to reach since it's generally located on the roof of your home. Use caution when reaching the vent opening.Now that we've established all that, here's how to accomplish the goal:

  1. Check for Blockages: Once you have located and reached the opening to the vent stack and before attempting to clear the vent pipe, it's important to check for any visible problems such as leaves, debris, or animal nests. If this is the case, your solution is simple! Grab the debris and dispose of it. If that is not the case...
  2. Use a Plumbing Snake: You may need to use a plumbing snake to clear any deeper debris. Insert the snake into the main vent pipe, rotate it clockwise, and at the same time, move it forward. Keep feeding the snake into the vent pipe until you reach the problem, then continue to twist and push the snake until the blockage is broken up. You'll be able to feel the difference.
  3. Flush the Vent Pipe: Once the debris is cleared, you should flush the pipe to ensure that it is flowing well. The easiest way to accomplish this is to use your garden hose. Simply place the end of the garden hose into the top of the main vent stack and run it for a while. The water should clear any remaining debris and fix your gurgling sink.

Replacing the Air Admittance Valve

Replacing this valve (which we will henceforth refer to as AAV) is a fairly simple task that can be done by most homeowners who have basic plumbing skills. Keep in mind, these steps are very general.

  1. Turn off the water supply: Before you replace the AAV, turn off the water supply to the affected fixture. There is almost
  2. Remove the old AAV: Using a wrench or pliers, loosen and remove the old valve from the vent pipe. If the valve is glued or welded to the vent pipe, you may need to use a hacksaw to cut it off.
  3. Clean the vent pipe: Once the AAV is removed, use a wire brush or cleaning solution to clean the vent pipe and remove any residual debris.
  4. Install the new AAV: Insert the new AAV into the vent pipe and tighten it in place using your wrench or pliers. Once that is all securely fastened, turn the water back on and test that everything is functioning properly.

Hiring a Professional Plumber

If there's a plumbing fixture you're not comfortable working on yourself, it is better to call a professional than destroy something.There are several benefits to not doing it yourself:

  1. Most companies will accept responsibility for damages, should something go awry.
  2. You are paying a set price for a fixed outcome.
  3. They will have all the supplies and tools with them. No need to make unnecessary trips to the hardware store.
  4. A professional can provide you with expert guidance for the future, whether that's about maintenance you can do yourself or how to see the signs of smaller problems before they escalate.

As with every home repair, you must weigh your decision. Will you pay for a professional and hand off the responsibility? Or will you save the money and potentially weather some risk?

Tips for Preventing Future Kitchen Sink Gurgling Issues

Regular inspections of your drain pipes and valves can prevent a lot of issues before they begin and catch small issues before they turn into emergencies. It can also help you know what maintenance is truly worth your time and money.

Thinking of Hiring A Professional?

Hiring a professional can be tricky. It is best to research your local options and read reviews before placing a call.Websites such as Yelp or Angie's List can really help simplify the process and help you feel secure in your decision.