How to Clear a Clogged Kitchen Sink

A clogged kitchen sink stops work cold. Water backs up, dishes pile, and suddenly you're thinking about calling a plumber. But most clogs live in the first three feet of pipe below your sink—the P-trap and the horizontal run to the wall. You can clear these yourself with tools you already own or can borrow. The key is knowing what you're working with: Is it grease? Food? Soap scum? A foreign object? The answer changes your approach. A backed-up sink is fixable in under an hour, and you'll know exactly what went wrong so you can prevent it next time.

1. Clear the Visible Blockage. If water is sitting in the sink, remove as much as you can with a cup or small bucket. Set aside a shallow pan under the sink to catch water when you disconnect pipes later. Look down the drain opening and pull out any visible hair, food bits, or buildup with your fingers, a paper towel, or needle-nose pliers. This clears the opening and often frees up a partial clog.
2. Plunge Before You Panic. Fill the sink halfway with water (this creates the seal plungers need to work). Place a wet washcloth or rag over the overflow hole if your sink has one—this keeps air from escaping and weakens the plunger's force. Position the plunger cup flat over the drain opening and pump vigorously 15-20 times without lifting it off the sink. Pull up sharply on the final stroke. Repeat this cycle 3-4 times. Listen for water draining or feel for suction change; either means the clog is moving.
3. Melt the Grease. If the clog clears or the plunger loosened it, boil a kettle of water and pour it slowly down the drain in a steady stream. The heat dissolves residual grease and pushes loosened debris further down the line. If the sink is still clogged but draining slowly, boil water anyway—this is your best shot at breaking down grease without tools or chemicals.
4. Activate the Fizz Reaction. If water still isn't flowing freely, remove any remaining standing water. Pour half a cup of baking soda down the drain, then follow it with half a cup of white vinegar. You'll see fizzing—that's the reaction working on buildup. Cover the drain opening with a plug or wet cloth for 15 minutes to keep the reaction working inside the pipe. After 15 minutes, boil a kettle of water and flush the drain with it.
5. Expose the P-Trap. If the sink still won't drain, you're moving to the P-trap—the curved pipe section below the sink. Open the cabinet under the sink and locate the U-shaped pipe. Place your shallow pan directly under it. Locate the slip nuts (the large hand-tightened fittings) where the trap connects to the vertical pipe above and the horizontal drain line. Loosen these nuts by hand first; if they're tight, use a pipe wrench or adjustable wrench to crack them loose, then finish by hand. Once both nuts are loose, the trap should slide down and out.
6. Excavate the Trap. Hold the removed P-trap over your pan and pour the trapped water out. Use a straightened wire coat hanger, a plumbing auger, or a small brush to push through the curved section and dislodge buildup. Push from both ends if needed. Rinse the trap under running water. If you see a solid object (a pit, a toy, a coin), remove it. Some traps have a slip nut at the bottom that unscrews to open a cleanout port—if yours does, unscrew it and push the debris out from inside.
7. Snake the Line Deep. If the P-trap is clean but water still won't flow, the clog is deeper in the horizontal line running to the wall. Disconnect the horizontal drain line from the vertical pipe above the trap (this is another slip nut). Insert a drain snake or straightened wire into the opening and push it toward the wall, feeding it 3-4 feet at a time. Work it back and forth and twist it to snag hair or buildup. Pull the snake back slowly, feeling for resistance. Repeat pushing and pulling 3-4 times until water flows freely through the open pipe.
8. Reconnect With Care. Once the drain line is clear, hand-tighten the slip nut connecting the horizontal line back to the vertical pipe. Slide the P-trap back into position and hand-tighten both slip nuts—the one at the top and the one at the bottom. Tighten them snug by hand, then use a wrench to turn each one another quarter-turn. Don't over-tighten; these nuts are designed to be removed by hand next time, and over-tightening makes future access difficult.
9. Verify the Fix Works. Fill the sink basin and release the stopper, watching the drain closely. Water should flow steadily without backing up. Listen for gurgling from the drain line as water moves through. If everything drains smoothly, close the cabinet and you're done. If water still drains slowly, repeat the snake process or consider calling a plumber—the clog may be past the P-trap in the main drain line.
10. Block Future Clogs. Place a mesh drain screen in your sink opening. These catch hair, food bits, and debris before they reach the trap. Empty the screen after every few uses. This single step prevents 80 percent of kitchen sink clogs.