Clear a Clogged Bathroom Sink Drain

Bathroom sink clogs happen because hair, soap scum, and toothpaste paste accumulate in the trap and drain line—usually right where the drain descends under the sink. The water pools, drains slowly, then stops entirely. The good news is that bathroom sink clogs almost never require a plumber. They live close to the surface, you have direct access from below the sink, and the tools that clear them cost less than a service call. You'll know you're done when water drains freely and the smell of stagnant water is gone. The key is knowing which method to try first. A plunger works on soft blockages made of hair and soap. A drain snake works on physical obstructions—hair clumps, toothpaste buildup, or debris. Chemical drain cleaner works on grease and mineral deposits but is your last resort because it's harsh and can damage old pipes. Most professionals start mechanical, then go chemical only if the blockage won't budge.

1. Expose the Hidden Hair Mat. Unscrew or lift the pop-up drain stopper from the sink. Most are held by a rod that connects to a pivot nut under the sink—loosen the nut and pull the stopper up and out. Look directly into the drain opening. You'll often see a visible mat of hair wrapped around the stopper or lodged at the drain entrance. Pull out whatever you can reach with your fingers or needle-nose pliers. Dispose of it in the trash, not down another drain.
2. Block the Escape Route. Fill the sink halfway with hot water. Locate the small overflow hole near the rim of the sink—this is usually a dime-sized opening on the side wall of the bowl. Plug it completely with a wet cloth or your palm. This forces all the plunger's pressure straight down into the drain instead of escaping through the overflow.
3. Create Suction, Break the Clog. Position a cup plunger (the flat-bottomed type, not a flange plunger) directly over the drain opening so it creates a seal. Push down and pull up rapidly 15 to 20 times without breaking the seal. On the final push, jerk the plunger away suddenly to create a suction pop. Check if water drains. Repeat the sequence two or three times if the first attempt doesn't fully clear it.
4. Know What You're Dealing With. Watch the water drain. If it goes down fast and the sink empties completely, the clog is cleared. If water still pools and drains slowly, the blockage is deeper and you need to move to a drain snake. If nothing drains, you may need to try chemical cleaner next.
5. Detach the Clog Trap. Look under the sink at the curved P-trap—the U-shaped pipe below the drain opening. Place a bucket underneath it. Locate the slip nuts on both ends of the trap. Using a basin wrench or adjustable wrench, loosen the nuts by turning counterclockwise. Once hand-loose, unscrew them the rest of the way by hand. Remove the trap carefully and pour any accumulated water and debris into the bucket. Set it aside on a rag.
6. Purge the Pipe Blockage. Use a straightened wire hanger or a plumbing snake to probe the opening where the trap was attached. Fish out hair, soap, and debris. Check inside the trap itself by turning it under light—you'll see buildup on the inside walls. Rinse the trap thoroughly with hot water over the bucket to flush out debris. If heavy buildup remains, soak the trap in hot water and a small amount of white vinegar for 15 minutes, then scrub with a brush.
7. Reach the Deep Blockage. If the trap was clear but the clog persists deeper in the wall line, feed a drain snake (also called a hand auger or plumbing snake) into the opening where the trap connected to the wall. Push it slowly but steadily, turning the handle clockwise as you feed it. You should feel resistance as it travels through the pipe—this is normal. When you feel a hard stop, the snake has hit the blockage. Crank the handle firmly several times to break through or grab the clog.
8. Reconnect and Verify Flow. Reattach the trap by hand-threading the slip nuts back onto the tailpiece and the wall drain opening. Tighten by hand until snug, then use your wrench to give each nut a final quarter turn. Don't over-tighten or you'll crack the fitting. Fill the sink with water and watch it drain. Check under the sink for leaks. If water drips from the slip nuts, tighten them slightly more.
9. Restore the Drain Stopper. Reach under the sink and locate the pivot rod assembly where you removed it earlier. Slide the pivot rod back through the opening in the stopper body. Tighten the pivot nut hand-tight under the sink. Pull the rod upward slightly to check that the stopper closes fully when you push it down, and opens when you pull it up. Adjust the rod position if the stopper doesn't seal completely.
10. Deploy the Chemical Weapon. If mechanical clearing hasn't worked, chemical drain cleaner can dissolve stubborn mineral deposits or grease. Read the product label carefully. Pour the recommended amount directly into the drain (the sink must be empty, with no standing water). Do not mix different drain cleaning products. Leave it for the time specified—usually 15 to 30 minutes. Pour a full kettle of hot water down the drain to flush it. Wear rubber gloves and ensure the bathroom is well-ventilated. Never plunge after adding chemical cleaner.
11. Fizz Away Residual Buildup. Once the drain is fully clear and flowing, run hot water for a full minute to flush the line completely. Then pour a cup of white vinegar followed by a cup of baking soda down the drain. Let it sit for 30 minutes. This creates a fizzing action that clears remaining debris and deodorizes the line. Follow with another minute of hot water. The drain should now smell fresh and flow quickly.