How to Unclog a Kitchen Sink: 7 Methods, From Easiest to Last Resort

To unclog a kitchen sink, start with the easiest fix and work up: pour a kettle of boiling water down the drain, plunge with a cup plunger while sealing the second drain, then remove and clean the P-trap under the sink. If water still won’t move, run a hand-crank drain snake through the wall pipe. Skip liquid drain cleaners — they rarely clear grease clogs and they damage pipes and disposals.

Kitchen clogs are almost always cooking grease that cooled and hardened inside the pipe, with food scraps, coffee grounds, and soap scum stuck to it. That matters because grease clogs respond to heat and mechanical force, not to chemicals. Here’s the full sequence, plus how to tell when the clog is past the sink and into the main drain.

Before you start: is it just the sink?

Run water in the bathroom sink and flush a toilet. If those drain normally, your clog is local to the kitchen line and everything below will work. If water backs up in multiple fixtures, or the lowest drain in the house (a shower or floor drain) is bubbling, the clog is in the main sewer line — skip to the last section, because nothing you do at the sink will fix it.

Method 1: Boiling water (grease clogs)

1. Bail out as much standing water as you can with a cup.
2. Boil a full kettle and pour it directly down the drain in two or three stages, waiting a few seconds between pours.
3. Run hot tap water. If it drains, follow with a squirt of dish soap and more hot water to flush the softened grease all the way out.

Skip this method if you have PVC pipes with glued joints that are already loose, or a porcelain sink — pour it directly into the drain opening, not on the sink surface. Never use boiling water if you’ve already poured a chemical drain cleaner; the combination can boil back up at you.

Method 2: Dish soap and hot water

For a slow drain rather than a full stop, squirt a quarter cup of dish soap down the drain, let it sit for 10 minutes, then flush with very hot tap water. Dish soap is a degreaser — it does the same thing to a grease clog that it does to a greasy pan.

Method 3: Plunge it (the right way)

1. Use a cup plunger (flat bottom), not a toilet flange plunger.
2. If you have a double sink, stuff a wet rag tightly into the second drain, or have someone hold a stopper over it. Without a seal, you’re just pushing air out the other side.
3. If there’s a dishwasher, clamp the dishwasher drain hose or you’ll push dirty water back into the dishwasher.
4. Fill the sink with a few inches of water so the plunger cup is submerged, then plunge hard 15–20 times. Pull up sharply on the last stroke.
5. Run water to check. Repeat two or three times before moving on.

Method 4: Baking soda and vinegar

Pour a cup of baking soda into the drain, follow with a cup of white vinegar, and cover the drain with a stopper for 15 minutes. Flush with hot water. The fizzing helps loosen light buildup and it deodorizes the drain. Be honest with yourself about this one: it’s good maintenance and it clears minor slow drains, but it won’t break through a solid grease plug.

Method 5: Clean the P-trap

The P-trap is the U-shaped pipe under the sink. Because it holds water, it’s also where scraps and grease collect. Cleaning it fixes most kitchen clogs.

1. Place a bucket under the trap and clear the cabinet.
2. Loosen the two slip nuts by hand or with channel-lock pliers (turn counterclockwise). Plastic nuts usually turn by hand; chrome ones may need the pliers.
3. Pull the trap off and dump it into the bucket. Scrub it out with a bottle brush.
4. Look into the pipe going into the wall (the trap arm). If you can see the clog, pull it out with a bent coat hanger.
5. Reassemble, hand-tightening the nuts plus a quarter turn. Run water and check for drips.

Method 6: Snake the drain

If the trap was clean, the clog is farther down the wall pipe. Rent or buy a 25-foot hand-crank drain snake (drum auger).

1. With the P-trap removed, feed the cable into the trap arm at the wall.
2. Push until you feel resistance, then tighten the set screw and crank clockwise while pushing gently.
3. When the cable breaks through or grabs something, keep cranking for a few turns, then pull back and clean the cable.
4. Reinstall the trap and run very hot water for several minutes to flush the loosened debris.

Don’t force the cable if it stops hard — you may be at a pipe fitting, and forcing it can punch through old pipe.

Method 7: Check the garbage disposal

If your sink has a disposal, it’s often the clog. Turn off the power at the switch (and the breaker to be safe), look inside with a flashlight, and remove anything stuck with tongs — never your hand. Turn the impeller plate manually with the hex key that fits the socket on the bottom of the unit, then press the red reset button. If the disposal hums but won’t spin, see our guide on a garbage disposal that’s humming but not working.

How to keep it from happening again

• Wipe greasy pans with a paper towel before rinsing, and pour cooled fat into a can for the trash — never down the sink, even with hot water.
• Coffee grounds, eggshells, rice, pasta, and fibrous vegetables (celery, onion skins) go in the trash or compost, disposal or not.
• Once a month, run very hot water for a minute, then dish soap and more hot water.
• Use a sink strainer and empty it into the trash.

When to call a plumber

Call a professional when the trap is clean and the snake didn’t clear it, when the clog comes back within a month, when both kitchen and bathroom drains are slow, or when you notice a sewage smell or gurgling from other drains. Those are signs the blockage is in the branch line or main sewer line — and in many Tampa Bay homes built before the 1980s, the culprit is scale and grease built up inside aging cast iron drain pipe. A plumber can hydro-jet the line clean and run a camera inspection to show you exactly what’s inside, which beats guessing with a snake.

Frequently Asked Questions

How do I unclog a kitchen sink with standing water?

Bail out most of the water first, then plunge with a cup plunger while sealing the second drain. If plunging fails, put a bucket under the sink, remove the P-trap, and let it drain into the bucket. Then clean the trap and snake the wall pipe if needed.

Why is my kitchen sink clogged on both sides?

On a double sink, both bowls share one P-trap and one drain line. A clog in the trap or the pipe past it backs up both sides. Clean the trap first; if it’s clear, the blockage is in the trap arm or the branch line behind the wall.

Can I use Drano in my kitchen sink?

We recommend against it. Chemical drain cleaners rarely dissolve a compacted grease clog, they can damage PVC, old metal pipes, and disposal seals, and they make the sink hazardous to plunge or snake afterward. Heat, plunging, and a snake are safer and more effective.

How do plumbers unclog a kitchen sink?

A plumber will typically use a powered drain auger for a standard clog, or a hydro-jetter — a high-pressure water hose — to scour grease off the entire inside of the pipe for recurring clogs. For repeat problems they may run a camera down the line to find the cause.

Why does my kitchen sink keep clogging?

Usually because grease has built up along the length of the drain line, so each new clog forms faster. Snaking punches a hole through buildup but leaves the rest; hydro jetting removes it. A sagging or improperly sloped drain pipe can also cause recurring clogs.