How to Unclog a Sink: 7 Methods, From Easiest to Hardest
Start with hot water and a cup plunger, then clean the P-trap under the sink. If that fails, use a drain snake. Save chemical cleaners for last.
How to unclog a sink: clear the stopper, flush the drain with hot water, then plunge it with a cup plunger. If it’s still slow, remove and clean the P-trap (the U-shaped pipe under the sink), and if the clog is past the trap, use a drain snake. These steps fix most kitchen and bathroom sinks without chemicals.
Kitchen sinks usually clog with grease, food scraps and coffee grounds. Bathroom sinks clog with hair, soap scum and toothpaste. The methods are similar, but the likely clog tells you where to look first.
1. Clean the stopper or strainer
In bathroom sinks, the pop-up stopper catches a surprising amount of hair and gunk. Pull it straight up, or unscrew the pivot nut behind the drain pipe under the sink to release it.
Wipe the stopper clean and try the water. In a kitchen sink, empty the basket strainer and check the garbage disposal, covered in step 6.
2. How to unclog a sink with hot water and dish soap
For a slow drain, this is the easiest first move. Squirt some dish soap into the drain, then pour in a kettle of very hot water in two or three stages.
If your drain pipes are PVC plastic, use hot tap water rather than boiling water, since repeated boiling water can soften joints. This works best on grease clogs in kitchen sinks.
3. How to unclog a sink with a plunger
Use a flat cup plunger, the kind made for sinks. Fill the sink with a few inches of water so the cup is covered.
Block the overflow hole in a bathroom sink with a wet rag. In a double kitchen sink, plug the other drain with a stopper or rag so pressure isn’t lost. Then plunge firmly 15 to 20 times and pull off quickly. Repeat a few times before moving on.
4. Remove and clean the P-trap
The P-trap is where most clogs sit, and cleaning it is the most reliable part of how to unclog a sink. Put a bucket underneath, then loosen the two slip nuts by hand or with channel-lock pliers.
Dump the water and debris, scrub the trap with an old toothbrush, and check the pipe going into the wall. Reassemble, hand-tighten the nuts plus a small quarter turn, and run water to check for leaks.
5. How to unclog a sink with a drain snake
If the trap is clean and the sink is still clogged, the blockage is farther down the pipe. A hand drain snake (also called a drain auger), usually 15 to 25 feet long and about $15 to $40, reaches it.
With the trap removed, feed the cable into the wall pipe and turn the handle as you push. When you feel resistance, keep rotating to break up or hook the clog, then pull it out. A cheap plastic barbed strip works well for hair in bathroom sinks.
6. Reset or clear the garbage disposal
If only the side with the disposal is clogged, turn the disposal off and unplug it or switch off its breaker. Never put your hand inside.
Use the hex key that fits the socket on the bottom of the unit to turn the motor back and forth, then press the red reset button. Remove any visible objects with tongs. Run cold water and turn it on to test.
7. Chemical drain cleaners: use with caution
Chemical drain cleaners contain strong bases like sodium hydroxide or acids like sulfuric acid. They can work on hair and grease, but they can burn skin and eyes, damage older pipes and finishes, and make any later plunging or snaking dangerous.
If you use one, follow the label exactly, wear gloves and eye protection, and ventilate the room. Never mix drain cleaners with each other or with bleach, and never mix bleach with ammonia or vinegar, which releases toxic gases. Enzyme-based cleaners are slower but much gentler for regular maintenance.
Quick reference: how to unclog a sink by symptom
| Symptom | Likely cause | Best first step |
|---|---|---|
| Bathroom sink drains slowly | Hair on the stopper | Pull and clean the stopper |
| Kitchen sink full of greasy water | Grease clog | Hot water, soap, plunger |
| Standing water in both kitchen basins | Clog past the trap | Clean P-trap, then snake |
| Only disposal side clogged | Jammed disposal | Hex key and reset button |
| Several drains slow at once | Main line blockage | Call a plumber |
When to call a plumber
Knowing how to unclog a sink yourself saves a service call, but some problems need a pro. Call a licensed plumber if water backs up into another fixture, if you smell sewage, or if the clog returns within days.
A plumber can use a motorized auger or hydro-jetting to clean the line. A typical drain-clearing visit commonly costs about $100 to $300, more for after-hours service or main-line work. If a pipe inside a wall has failed and caused water damage, contact your homeowners insurance to ask about coverage.
FAQ
Does Dawn really unclog drains?
Dish soap helps loosen grease clogs, especially with hot water, but it won’t clear hair or solid objects. It’s a good first step, not a cure-all.
Why should you never use baking soda and vinegar to unclog a drain?
It isn’t dangerous, but the fizzing reaction mostly neutralizes itself and has little power against real clogs. It can also give you false confidence while the clog gets worse.
What do plumbers use instead of Drano?
Mostly mechanical tools: plungers, hand augers, motorized drain snakes and hydro-jetting. They clear the clog without harsh chemicals sitting in the pipes.
How do you unblock a badly blocked sink?
Remove and clean the P-trap, then run a drain snake into the wall pipe. If that doesn’t work, the blockage is likely in the branch or main line and needs a plumber.
Bottom line
When you’re figuring out how to unclog a sink, go mechanical first: clean the stopper, flush with hot water, plunge, then clean the P-trap and snake the line. Use chemical cleaners only with care, never mix products, and call a plumber when several drains back up.