To unclog a kitchen sink, remove standing water if you can, then plunge with a flat-bottomed cup plunger while blocking the second drain and the dishwasher line. If the water does not move, put a bucket under the P-trap and clean it. If that fails, feed a snake through the trap arm. Related jobs live in our drain cleaning and clogs hub.
How do I unclog a kitchen sink with standing water?
Start with a plunger, because it is the least messy fix and clears many grease and food clogs. Bail out most of the water, leaving enough to cover the cup. Seal the plunger over the drain, plug any second drain and the overflow, and push and pull firmly for about twenty seconds.
- Switch off the garbage disposal if you have one, and stay clear of it with your hands.
- Bail water into a bucket until about two inches remain over the drain.
- Stuff a wet rag into the overflow hole, if there is one, and the other drain.
- Press the cup flat over the drain and plunge ten to fifteen times.
- Lift the plunger away and check whether the water level drops.
- Repeat in rounds, up to five times.
A kitchen plunger has a flared rubber cup that seals on a flat sink bottom. A plunger works through pressure and suction to dislodge the blockage. Do not use the plunger you use on toilets without washing it well. If the water starts to drain, let hot water flow for sixty seconds to wash loose grease off.
How do I clear the P-trap under a kitchen sink?
Place a bucket beneath the trap, unscrew both slip nuts by hand or with pliers, and drop the trap down. Pour out the contents, scrape the inside with a brush or old rag and rinse it. Reinstall it with the washers lying flat and the nuts snug by hand, then turn on the tap and inspect every joint.
The P-trap is the U-shaped section just below the sink, and it is where most kitchen clogs settle, because grease and food scraps pool in the low point. Look into the pipe leading to the wall, too. If you see packed material in the tail pipe, a short snake can reach it.
Check the washers for cracks and replace them if they look flattened. If a joint drips after you refit it, tighten a quarter turn, or see how to repair a leaking pipe under the sink. Even a slow drip shows up on a dry paper towel placed beneath each joint.
What if I have a double sink or a dishwasher connected?
On a double basin, both sides share one trap, so a clog below it affects both. Block the second drain with a stopper or wet cloth so the plunger pushes against the clog. A dishwasher drain hose often joins above the trap or at the disposal, and a clog there can send dirty water back into the dishwasher.
If a dishwasher is connected, pinch off the hose or hold the cloth hard so pressure does not escape. If the dishwasher fills with gray water after you run the sink, the clog is past the connection. Our guide on how to unclog a dishwasher drain covers the hose and air gap, and our garbage disposal guide covers the disposal.
How do I use a snake on a kitchen sink drain?
A plumber's snake, also called a drain auger, is a slender flexible cable that you feed into the pipe to break up or hook a clog. For a kitchen sink, remove the trap first and feed the cable through the wall pipe, turning the handle as it goes, then pull back whatever it catches.
Technique:
- Push in roughly a foot per go, turning the handle clockwise.
- When you feel resistance, keep turning to break the clog or bite into it.
- Pull the cable back slowly. Expect grease and food on the end.
- Put the trap back and run hot water for a minute to confirm flow.
- Wipe the cable before you store it.
Once the cable is fully extended and water still stands, the blockage lies beyond a hand snake's reach, or sits in the branch line. Stop pushing against it, as a stuck cable can scratch old pipe.
Why does my kitchen sink keep clogging?
Grease is the main cause. Warm fat runs off a pan as a liquid, but it cools in the pipe and sticks to the walls, where food, soap and coffee grounds pile on. Over months, the pipe narrows. Fix the habit, and the clogs stop.
Common causes of repeat clogs:
- Pouring cooking fat or oil down the drain.
- Coffee grounds and eggshells.
- Rice, pasta and potato peels, which swell with water.
- Fibrous scraps through the disposal.
- A pipe that slopes too little, or a partly blocked vent.
- A buildup farther down in the branch line or main.
Scrape pans into the trash, wipe greasy dishes with a paper towel and use a sink strainer. Across Los Angeles, restaurants fall under LA Sanitation's grease program, but at home the same simple habit applies.
Can I use drain cleaner in my kitchen sink?
It is better not to. The National Capital Poison Center warns that lye-based drain cleaners are highly caustic and may burn skin and lungs, and it advises against mixing cleaning products at all. In a sink with standing water the chemical sits where you work, and splashback is a real risk. Chemicals also harm a plastic trap or old metal.
Hot tap water can soften light grease. Do not pour boiling water on a plastic pipe or a porcelain sink. If you have already used a cleaner, do not plunge, wear gloves and goggles, and tell any plumber. After splashes or fumes, get to fresh air, rinse with water and ring Poison Control on 1-800-222-1222.
When should I call a plumber for a clogged kitchen sink?
Call a plumber if the sink is still full after the plunger, trap and snake, if other drains back up, or if the pipe leaks or is damaged. If bathroom fixtures gurgle simultaneously, suspect the main line, which a hand tool cannot handle.
Within Los Angeles city limits, the owner generally carries the private lateral from the house to the street tie-in, while LA Sanitation runs the public main, and a camera can show on which side the blockage lies. Request a written quote through our quote page and a local plumber will be lined up for you. For a guide to prices, read the cost to unclog a sink. The home page shows how a job runs.
Common questions
What is the fastest way to unclog a kitchen sink?
Bail out most of the water, plug the second drain and overflow, and plunge with a flat cup plunger for about twenty seconds, repeating a few times. If it stays blocked, pull the P-trap and clean it above a bucket. Those two steps clear most kitchen clogs within thirty minutes without any chemicals.
Why is my kitchen sink full of water and not draining?
Something is blocking the pipe below the sink, most often grease and food in the P-trap or the branch drain. If the other basin of a double sink is also full, they share the clog. A disposal that is jammed or a dishwasher hose can also hold the water back, so check both.
Will boiling water unclog a kitchen sink?
Hot water eases a thin grease film, yet it cannot clear a solid plug, and boiling water can damage plastic pipes, soften joints and crack porcelain. Stick to the hottest tap water, never boiling. With a real clog, plunge or clear the trap first then follow with a hot water flush.
Can I use a plunger if I have a garbage disposal?
Yes. Turn the disposal off, keep your hands clear, and block the second drain and dishwasher line. Plunge the disposal drain firmly. If the disposal itself hums or is jammed, free it with the hex key socket underneath, as explained in our disposal guide, before you plunge.
How long does it take to unclog a kitchen sink?
Plunging takes five to fifteen minutes. Cleaning the P-trap adds about twenty minutes, and a snake pass maybe another half hour. If you are still working after an hour, the blockage likely sits in the main or branch line, and a plumber with a longer cable, or a camera, can typically finish in one visit.