A gurgling sound from your kitchen sink drain does not bode well. However, it doesn’t always necessitate a call to a  professional plumber.

In many cases, homeowners can fix the cause of the gurgling noise all by themselves, as long as they know what to do. 

There are a few different plumbing problems that can cause a gurgling drain, ranging from minor blockages to serious problems. For that reason, troubleshooting is an essential first step in dealing with the issue. 

Incorrectly Installed Sink Vent 

If the gurgling only ever happens when the water is draining, that’s likely to be a problem with the sink vent. 

Make sure that the sink vent is correctly installed. For standard 1.5-inch diameter drain pipes, the main vent should be installed no more than 3.5 feet away from the p-trap.

If it’s not, and can cause a vacuum to develop, which can cause the gurgling. 

All you have to do to fix it is reinstall the sink vent the proper distance away from the p-trap. It’s a pretty easy fix.

The hardest part will probably be the trip to the hardware store to pick up the pipes you need.

Blocked Main Vent

However, the sink vent isn’t the only vent opening in your plumbing system. If the gurgling in your kitchen sink happens when you flush the toilet or drain your bathtub, it may be an issue with the main vent of your vent system. 

In this case, you’ll want to act fast, because if the vacuum gets worse, it can cause the sink trap to drain, allowing air bubbles of sewer gas to make their way up to your sink. No one wants their home filled with sewer smell.

Fortunately, it’s a pretty easy fix. A main vent frequently is accessible from the roof above the main bathroom, where you can flush it with water from a hose.

You can also use a sewer auger to break up any clogs. It’s important to use a sewer auger specifically because a sewer auger is long enough to break up a clog anywhere from the vent opening to the main sewer line.

Worn Or Clogged Air Admittance Valve

Not all sinks have vent pipes. Those that don’t will have an air admittance valve instead, but like a vent, the air admittance valve can also cause gurgling.

If the air admittance valve is clogged or damaged, it disrupts the air pressure in the sink’s plumbing system. 

You can locate your air admittance valve under the kitchen sink, right after the p-trap.

An air valve with a problem is super easy to replace. You can pick up a new one at most home improvement stores, usually for around $20 or less.

Then simply unscrew the old one by hand and screw the new one in its place.

Clog In The Kitchen Drain Pipe

In other cases, the cause is as simple as a clogged drain. Over time, debris can build up in your pipes, eventually causing a blockage.

Hot Water

The first step to try to clear a blockage is to simply flush your sink with hot water. The flow of water may be enough to move whatever debris is in the pipe out of the way.

Just be sure to keep an eye on the sink while the water flows. If clogging is severe enough, it may cause the water to back up and you don’t want the sink to overflow.

Water from your faucet may not be hot enough, but if it doesn’t work, you may want to try boiling water, then immediately pouring it down the sink to see if it will remove particularly stubborn food debris.

If that still doesn’t work, you can try using a plunger to move the clog, or try to break up the clog with an auger or a plumbing snake. 

Vinegar & Baking Soda

If water alone doesn’t do the trick, you can take it up a notch with baking soda and white vinegar.

First things first, set up a pot of water on the stove to start boiling. You can get started on the next steps and by the time you’re done, the water should have reached a boil.

Now pour some baking soda down the drain. You’ll need to use at least a few tablespoons, but you can definitely use more than that for especially stubborn clogs.

Then pour some white vinegar down the drain after the baking soda.

If you’ve ever made a paper-mâché volcano before, you know what happens now. The vinegar and baking soda interact to create a bubbling, foaming effect.

This interaction can help loosen up clogs. Let the baking soda and vinegar do their thing until they stop bubbling or until your water starts boiling, whichever comes second.

Finally, pour the boiling water down the drain to loosen up and flush out any lingering debris.

Use A Plunger

To move a clog in a sink, you’ll need a cup plunger that will completely seal over the drain, which means you’ll probably need a smaller plunger than the one for your toilet. 

Once you’ve grabbed your plunger, remove the basket strainer and drain assembly. 

Fortunately, most kitchen sinks don’t have an overflow drain, so you shouldn’t need to worry about that. However, if you have a double basin sink, you will need to seal one drain.

You can put duct tape over the other drain to prevent air from escaping. Just make sure it completely closes off the drain.

Now put the plunger over the open drain, making sure it completely seals. Adding a couple of inches of water to the sink will help you ensure a secure seal.

Then quickly and firmly move the handle of the plunger up and down. Take care to leave the seal intact.

The motion of the handle will force air into the drain, forcing the clog to move. 

If you have a double basin sink, be sure to keep an eye on the other, sealed drain to make sure that it doesn’t come uncovered. You may need to keep a hand over it or weigh it down with something hefty to make sure the tape stays in place. 

After a little while, run hot water down the sink to flush out any remaining debris and ensure that there’s no more gurgling.

Use An Auger

You can also use an auger to break apart a clog. Augers can be intimidating, but they’re actually pretty easy to use. 

Simply take out the drain assembly, then feed the snake down the drain until it hits the clog. Now extend another 12 inches or so of a drain snake, then secure the snake in position using the auger’s set screw or similar device. 

Once that’s done, you’ll need to turn the handle of the auger, causing the cable to rotate. This rotation breaks apart the blockage.

You may need to extend the additional length to break up clogs further down the pipe. 

Once you can’t find any more blockage with the drain snake, you can retract and clean the snake. Then rinse the drain using hot water to flush out leftover debris.

Should I Use A Drain Cleaner?

As a last resort, you can use a chemical drain cleaner, but be careful with them because they can severely damage your pipes. If you have a septic tank, make sure to use a drain cleaner that’s designed specifically for septic systems.

Standard drain cleaners can wreak havoc on a septic system.

How Do I Prevent My Kitchen Sink From Gurgling?

To prevent clogs in the future, be sure to scrape debris on dishes into the trash before rinsing them in the sink. Make sure you run the garbage disposal regularly, if you have one, to help prevent the build-up of food debris in the drain pipe.

Never pour oil, grease, or fat down the drain, as it can build up in your pipes. 

Regularly treating your drains with baking soda and vinegar can help loosen up debris before it gets the chance to build up too much.

Final Thoughts On Gurgling Kitchen Sinks

Hopefully, with the knowledge you’ve gained here, you’ll be able to easily DIY the fix for your gurgling kitchen sink.

If none of the above solve your sink gurgles, however, you’ll need to call a plumber to locate and resolve your plumbing issue. That’s a hassle that no one wants to deal with, I know, but it’s best to deal with plumbing problems ASAP. 

What can be a minor problem with a quick fix now can easily become a serious issue that leads to major damage, so don’t put off dealing with a gurgling sink!