Clear a Slow or Clogged Bathroom Sink Drain

A slow-draining bathroom sink is one of those problems that gets worse the longer you ignore it. Water pools around your feet while brushing teeth. Hair wraps around the stopper. The smell starts. But here's the thing: bathroom sink clogs live right at the surface, almost always in the first foot or two of pipe where soap, hair, and skin cells have matted into a plug. Unlike kitchen sink clogs, which might be grease three feet down the line, bathroom clogs are mechanical and visible. You can clear most of them yourself in under an hour with tools you probably own. The key is understanding that the clog isn't usually a mystery—it's a visible mass of hair and soap that needs to be pulled out, broken apart, or flushed clear. Do it right and you won't need a plumber.

1. Start at the surface.. Lift the sink stopper straight up. If it doesn't come free easily, look for a setscrew on the underside of the faucet body or a clip on the overflow pipe. Most pop-up stoppers unscrew by twisting counterclockwise beneath the sink. Once removed, rinse the stopper under hot water and scrape away hair and soap buildup with your fingers or an old toothbrush. This single step clears 30% of slow-drain complaints before you ever touch the actual pipe.
2. Pump before you reach.. Plug the overflow hole (if your sink has one) with a wet cloth so the plunger creates a seal. Fill the sink with 4 inches of hot water. Position a standard cup plunger directly over the drain opening and pump it vigorously 15 to 20 times, then pull it away sharply. The suction and pressure combination often dislodges hair and soap. Repeat this cycle 3 or 4 times. If water drains noticeably faster after the first round, you've found the blockage.
3. Fizz away the residue.. If plunging helps but doesn't fully clear the drain, try a chemical-free approach. Pour a half-cup of baking soda directly into the drain. Boil a kettle of water and slowly pour it down the drain over about 30 seconds. The baking soda reacts with the heat and creates a mild fizzing action that can break apart remaining soap and hair. Let this sit for 15 minutes, then run hot tap water for 30 seconds.
4. Open the trap.. Place a bucket under the U-shaped pipe (the trap) below the sink. Using an adjustable wrench, loosen the slip nuts on both ends of the trap by turning counterclockwise. The nut should hand-loosen after a quarter-turn with the wrench. Carefully unscrew by hand and slide the trap downward. A small amount of water will spill into your bucket—that's normal. Look inside the trap opening. You'll often see a visible plug of hair and soap right there.
5. Extract the clog.. Use your fingers, a small hook, or needle-nose pliers to pull out any hair, soap, or debris from inside the trap. Run your finger along the interior walls to feel for buildup. Empty the debris into your bucket. Take a flashlight and look up into the tailpiece (the vertical pipe that goes into the wall). If you see a visible mass of hair, use a drain snake or a straightened wire coat hanger with a small hook at the end to fish it out. Push firmly but gently—you're not trying to shove anything deeper.
6. Snake the line deeper.. If the trap is clear but the sink still drains slowly, a clog exists deeper in the wall line. Insert a handheld drain auger (snake) into the tailpiece opening. Crank the handle clockwise while applying gentle downward pressure. You'll feel resistance when the snake encounters the clog—keep cranking. The snake either breaks apart the clog or catches hair that you can pull back out. Advance the snake 12 inches at a time, then crank and push. Repeat until you feel the blockage clear or the snake goes slack.
7. Clear the debris.. Once the trap is clean and any deep clog is broken, reinstall the trap. Hand-tighten the slip nuts first, then use your wrench to snug them another quarter-turn—not tight enough to sit on, just hand-snug. Turn on the hot tap and let it run for 30 seconds to flush debris through. Check under the sink for any drips. If the trap leaks slightly at the connection, tighten the slip nuts another small turn.
8. Verify full drainage.. Replace the pop-up stopper assembly and adjust it so it closes fully and opens without sticking. Fill the sink with 4 inches of water and watch how fast it drains. It should empty noticeably faster than before. If it still drains slowly, the clog may extend beyond the wall trap into the main line—that's when you need a professional plumber with a motorized auger.