How to Unclog a Bathroom Sink Drain

Bathroom sink drains clog faster than any other drain in the house. Hair, soap scum, and toothpaste residue accumulate in the trap and tailpiece, and one day the water just sits there. The good news is that you don't need a plumber for this one. A clog that sits above the trap—the visible part—usually yields to a plunger or a cheap wire snake. If the water drains slowly or not at all, you're looking at a trap clog, which means getting your hands wet but saving yourself a service call. Most people find they can clear their own drain in under an hour with tools that cost less than a coffee.

1. Spot the Blockage Type. Fill the sink halfway with water and let it sit for 30 seconds. If it drains at all, the clog is minor and may respond to a plunger. If the water doesn't drain at all, you have a solid blockage. Check the overflow hole (the small opening near the rim of the sink) and make sure it's clear. Some bathroom sinks have a pop-up drain stopper—lift it out and look down the drain opening. Remove any visible hair, soap, or debris by hand or with needle-nose pliers.
2. Build Pressure Fast. Fill the sink with 3–4 inches of water. Place a wet cloth or your hand over the overflow hole to seal it—this is essential for plunger pressure to work. Push a cup-style plunger straight down over the drain opening and pump vigorously 15–20 times without lifting it away from the sink. The water should suddenly drain if the clog is shallow. Repeat two or three times if the first attempt doesn't work.
3. Fish Out the Clog. If the plunger doesn't work, straighten a wire coat hanger or use a cheap plastic drain snake (under $5 at any hardware store). Feed the wire down the drain slowly, pushing gently but not forcing. You'll feel resistance as you hit the clog. Once you feel the blockage, push and twist the wire to break apart the hair mass or pull it back out. Feed the wire down again and repeat until the drain flows freely.
4. Protect Your Cabinet Floor. If the wire snake doesn't work, the clog is in the P-trap itself. Place a bucket directly under the trap to catch water—expect 1–2 cups. Unscrew the large slip nuts on both sides of the P-trap by hand or with a wrench. The nut connecting the trap to the tailpiece (the pipe coming down from the sink) unscrew first, then the nut connecting the trap to the wall drain. Keep the trap level as you lower it to avoid spilling standing water.
5. Remove the Hair Mass. Hold the P-trap over the bucket and pour the standing water out slowly. You'll see the clog immediately—usually a matted ball of hair mixed with soap. Use needle-nose pliers or a small wire hook to pull out the debris. Once the visible clog is gone, rinse the inside of the trap by pouring fresh water through it over the bucket. Check the tailpiece (the vertical pipe coming from the sink) and the wall drain opening for blockages. If the wall drain is clogged, you may need a longer snake or professional help.
6. Don't Forget the Overflow. While the trap is out, take a moment to check the overflow pipe inside the sink cabinet. You'll see it connecting to the overflow hole near the rim of the sink. Use a wire or straightened coat hanger to poke through it and remove any debris. This is a common spot where secondary clogs hide.
7. Seal It Snug. Before screwing anything back together, check the rubber washers inside each slip nut. If they're cracked or flattened, replace them now (they cost under $1). Hand-screw the nut connecting the trap to the wall drain first, then hand-screw the nut connecting the trap to the tailpiece. Tighten both nuts an extra quarter-turn with a wrench, but don't over-tighten—you only need to stop water from leaking, not crush the fitting.
8. Check for Leaks. Fill the sink with water and run it while watching under the cabinet. The drain should empty smoothly within 5–10 seconds. Check both slip nuts for drips. If water leaks from either nut, tighten it slightly more. If water leaks from inside the trap itself, the rubber washer is damaged or the fitting is cracked—you'll need to replace that section.
9. Verify Full Flow. Once you confirm no leaks, fill the sink and let it drain at full speed three times. This flushes debris that may still be loose in the main drain line. If the drain slows down after the first flush and speeds up again on the second, the main line is clearing itself. If the water stays slow or backs up, you have a clog further down the line and may need a plumber.
10. Stop Hair Before It Clogs. To prevent this from happening again in 3–6 months, buy a simple mesh drain strainer or hair catcher (under $3) that sits in the drain opening. These catch 90% of the hair before it enters the trap. Empty it every week by lifting it out and throwing the debris in the trash. This single step cuts the number of clogs most households experience by two-thirds.