Kitchen Sink Makes Gurgling Noise When Toilet Is Flushed

Does your kitchen sink make gurgling noise when toilet is flushed? If it does, it indicates the presence of residue debris in the pipes or ventilation problems. In rare cases, it spells out that they are problems with the plumbing hardware.

So we will be looking at why the kitchen sink makes gurgling noise when toilet is flushed and how to remediate the issue.

Firstly, you have to understand the structure of the plumbing work of your sink and toilet to be effectively equipped to tackle this issue.

There are three components to the plumbing work of both the kitchen sink and toilet.

  • Drain waste: These are pipes that are used to move water and dirt down to the sewer.
  • Water seal: This is a seal that prevents the sewer gas from flowing back into the home.
  • Vent air: This helps to ensure the easy flow of the water in the pipe and it also helps protects the water seal through the use of ventilation.

Sometimes fixtures like toilets and sinks make use of a wet vent; this entails that they share a pipe that functions to drain water downward into the sewer pipe and at the same time pull air through an outside roof vent.

Each of these fixtures has its trap that helps create a water seal that prevents the sewer gas from rising into your home. So the gurgling noise you hear happens down in the plumbing trap itself, which is located under the sink. This trap is called the P trap or S trap.

The S traps are no longer in use now; you can only find them in old buildings, but if you still have an S trap, you have to quickly replace it with a P trap, for the P trap is found to be more effective, and less problematic.  

What Causes a Gurgling Kitchen Sink

When there is no access to the outside air, the vacuum down the system can pull air from another plumbing fixture, possibly the sink. So when the toilet is flushed, it pulls air from the sink, which removes the water in the trap. Thereby causing the sink to gurgle..

Also, built-in residue dirt trapped in the seal can cause a gurgling sound. Additionally, if the vent is blocked by ice, snow or debris, the trap seal will become sucked out with the draining water and gurgling sound.

How to Get the Gurgle out of a Sink When You Flush the Toilet

As stated earlier, the gurgling is caused as a result of the passage of air through the sink P-trap. It is necessary to tackle the problem immediately because it can spell danger if it persists.

Clearing the vents is as simple as plugging the toilet, but you may need to repair some pipes.

The steps of getting the gurgling noise out from the sink when toilet is flushed include:

  1. Close the sink drain, use duct tape to cover the overflow tubes, and plunge the toilet. Plunging the toilet helps to remove blockage, while a partial blockage waste pipe of the toilet may force the air through the sink drain, and covering the sink drain keeps the down the force of the plunger.
  2. After plunging, open the drain and flush the toilet. Carefully try to listen if there is any gurgling. If it is still there, try plunging again. You are to keep plunging until you’re sure that the gurgling has stopped.
  3. Next, climb the roof and check for the opening of the main vent stack, whether it is blocked by dirt or debris. If it has a screen, check whether the screen is dirty. If it is dirty, clean the screen and clear off the dirt.
  4. Next, using a garden hose, spray water down the vent pipe. This water helps to clear off any form of obstruction that is stuck deep inside the pipes. If you notice water backing up of the vent, it is a clear indication that the vent is blocked, you can use a sewer auger to remove the blockage, and you can easily get a sewer auger from any rental plumbing shop.
  5. Next, insert the auger into the vent opening and twist it until you feel some form of resistance, and then crank the handle to penetrate the head through the blockage. Periodically pull out the head to clear it of debris. When you noticed that the blockage has been cleared, spray more water in the vent and if it doesn’t back it, it confirms to you that there is no blockage.
  6. Next, look under the sink to check if the gurgling persists. If it does. You will see an air-admittance valve also called a cheater valve. It is connected to the horizontal arm of the P-trap. Using adjustable pliers, unscrew it and replace it with a new one. to get a new one is usually not expensive.

What Are the Things You Need to Get the Gurgle out of a Sink When You Flush the Toilet

They are:

  • Plunger
  • Air-admittance valve
  • Garden hose
  • Duct tape
  • Ladder
  • Sewer auger
  • Adjustable pliers

In severe cases, when the gurgling does not stop after following the steps above, do consult a plumber, it can be the case of inadequate venting which may require the installation of new pipes. Additionally, it may be the case of an ineffective, and illegal drain setup.

Frequent Asked Questions (FAQs)

When I flush my toilet the kitchen sink gurgles?

The gurgling sound you hear from the sink when you flush the toilet spell trouble, even though it sounds innocent.  There are many reasons why the sink gurgles, one is that the pipes aren’t properly vented, or the pipes are blocked with debris which can slow down the water flow and eventual lead to blockage. Kindly scroll up and read why the sink makes gurgling noise when the toilet is flushed.

Why are my sink and toilet gurgling?

The gurgling of your sink and toilet is a result of air being forced through water in your drain trap. The gurgling sounds often come from the shower/tub, but they can also come from your vanity sink or toilet. In general. gurgling is a sign of improper ventilation of your kitchen and toilet plumbing system as explained above.

 Why do my pipes gurgle when I flush the toilet?

When the pipe gurgle when you flush the toilet simply indicates that there is negative air pressure called suction building up in the drain line, thus creating an airlock. In a simple tense, gurgling indicates the presence if an abnormal suction building in the pipeline. This suction will eventually be released, pushing air backward through the drainpipe and down into the toilet bowl.

 Can a clogged drain cause gurgle?

A clogged drain is one major cause of gurgling. You can identify a drain that is clogged simply by tracing where the gurgling is coming out from. However, if turning on the sink in the kitchen causes a gurgling sound in your bathroom, this indicates that your main sewer line is clogged.

How do I stop my sink from gurgling?

One of the most effective ways to stop your sink from gurgling is by consistently pouring down hot water to clear out every form of blockage. If the gurgling persists, heat the water to a boiling stage and pour it down, and it will clear off.

 Can you fix a gurgling toilet yourself?

 If your toilet gurgling is due to the main water problem, you won’t be able to fix it yourself. That’s it your neighborhood responsibility, not yours. However, if the gurgling is due to improper ventilation, or residue dirt or debris, you can fix it yourself.  


I hope you love and found this article interesting. For more educative kitchen nuggets, do slide into the posts below.

Leave a Comment