How to Fix a Gurgling Kitchen Sink (Causes and Solution)


Noise coming from the kitchen sink is a cause of distress for many homeowners. The situation is even worse if foul smells accompany the offending sounds. What’s wrong with your fixture, and what to do about it? Should you call a plumber, or can you fix the kitchen sink yourself?

The gurgling noise you hear is actually air escaping the plumbing system. Chemical drain cleaner like Liquid-Plumr gives you a quick and cost-effective solution to fix the problem. Alternatively, you can unclog the blockage manually. If these solutions don’t work, you should call in a professional plumber.

Why Does Your Kitchen Sink Gurgle

Drain gurgling can happen for a number of reasons. More often than not, the problem is a clogged drain. Plumbing venting problems can also cause gurgling sounds. Here are the most common reasons why your kitchen sink might emit noise.

Clogged drain

A clogged drain is almost always the cause of the gurgling sounds. Kitchen sinks clog more often than the bathroom ones, mainly due to the food waste that ends up in the drain. Grease, soap scums, and scale can also build up on the pipes and cause a blockage. Clogs can hoard air bubbles around them, causing the water to gurgle as it runs around them.

Clogged sink past the P-trap 

A P-trap is a plumbing fixture you can spot under the sink. This bent pipe has two critical roles. For one, it traps waste and prevents clogs from forming down the plumbing line. It also stops sewer gases from escaping the plumbing system and passing into your home.

If a foul smell accompanies the gurgling sound, a clog past the P-trap is more likely the culprit. Luckily, these blockages are easy to fix.

Blocked vent pipe

If you didn’t know it, plumbing systems have vents designed to regulate airflow and ensure that the wastewater flows through the pipes and out of your house. A vent pipe blockage can cause a vacuum that prevents water from flowing freely (or at all).

Since most plumbing vents open on the roofs, birds or rodents can build their nests in them and prevent airflow. Leaves falling down the vents could also clog it. The problem is easy to fix.

Incorrectly aligned vent pipe

A far worse scenario happens when the kitchen sink gurgles, but you’ve just moved into a recently built or renovated home. 

If you can rule out clogs and blockages, the cause could be an incorrectly installed vent pipe. This issue is a pain to fix since you might have to re-project and reinstall a new vent system. Only a qualified plumber can carry out this work.

General drainage problems

Similar to incorrectly aligned vent pipes, general drainage problems must be addressed by a certified plumber. You can tell if your whole drainage system is messed up if the gurgling noise also comes from other fixtures, including your bathroom sink and toilet.

How to Fix a Gurgling Kitchen Sink in 5 Easy Steps

A plumber can effortlessly fix a gurgling kitchen sink, but before spending the money, you can try to fix the issue yourself. Here’s how. 

Step 1 – Unclog the pipes with liquid drain cleaner

Chemical drain cleaners are caustic or acidic substances that will liquefy the organic matter clogging the sink’s drainpipe, and you’ll be able to flush it with hot water. These products are effortless to use: simply pour the liquid into the drain and wait for 15-30 minutes, as instructed on your product’s package.

After this time, rinse the drain with abundant hot water. This solution is suitable for dissolving smaller clogs made up of organic matter, grease, soap scum, and scale.

Step 2 – Unclog the sink manually

Chemical drain cleaners may fail to work if the clog is too large. However, you may still be able to unclog the pipes manually.

You will need a plunger and a plumbing snake. Try using the plunger first. This action will dislodge looser clogs in the P-trap or in the upper sections of your kitchen sink’s drain. If the sink still gurgles, use the plumber’s snake to get rid of clogs stuck farther down the drain.

Step 3 – Check for obstructions inside the P-trap 

A clog blocking the P-trap could be harder to dislodge, even if you use a plumber’s snake or plunger. To rule it out, you have to disassemble the P-trap. 

First, position a bucket or plastic basin under it, then use pliers to remove the coupling nuts fixing the trap to the sink drain and pipe. Dislodge any clogs and clean the trap, then mount it back or replace it if it is damaged.

Step 4 – Check the vents for external waste

As mentioned above, the sink vents extend to the exterior of the house where animals or debris can cause blockages. 

Unclogging the sink vent isn’t complicated, but you’ll have to climb on the roof. More often than not, you’ll be able to clear the blockage with a garden hose: flush water through the pipe to dislodge any debris stuck in it. 

You can also use a plumbing snake or auger if the water doesn’t have enough pressure to remove the blockage. 

Step 5 – Check the air admittance valve 

If you live in a newer apartment block, chances are your plumbing system doesn’t have vents. In this case, the kitchen sink features an air admittance valve located underneath the sink. This pressure-activated valve can sometimes get stuck or, in rare cases, it might be clogged.

Inspect the valve to make sure that it works properly and to remove any clogs or blockages. Air admittance valves have an average lifespan of 20-30 years. Thus, if the sink makes gurgling sounds but the valve has only worked for a few years, you could have bigger plumbing problems. 

If nothing worked and your sink still makes funny sounds, you should call in a certified plumber to inspect the system and solve the issue.

FAQs: Kitchen Sink with Gurgling Sound

Is a gurgling sink dangerous?

If your sink only makes gurgling sounds, but there is no unpleasant smell, there is no danger to worry about. However, the sound could indicate a major plumbing problem. If you can smell an unpleasant odor coming from your sink, sewer gases may escape into your home. Sewer gases are toxic and can be dangerous, so you have to fix the problem as promptly as possible. 

Why are there bubbles in my kitchen sink?

Gurgling sounds and bubbles in the sink go hand in hand. When something blocks the natural water flow, the slower flowing speed causes air bubbles to form into the plumbing system, which will eventually cause gurgling noise. The main causes include an incorrectly installed P-trap and a clogged drain.

To End

Fixing a gurgling kitchen sink is usually easy, even without a plumber’s help. However, the noise could indicate a bigger problem that requires professional intervention. Gurgling noises that you can’t fix yourself are usually expensive to deal with, but it is crucial to solve the problem without delay.

Recent Posts