● DIY-Safe

Last updated: March 2026 · Reviewed by the Toolbox Team

How to Unclog a Sink

A clogged or slow-draining sink is one of the most common plumbing issues. In the kitchen, it's usually food and grease buildup. In the bathroom, it's hair and soap scum. Most clogs are near the drain and can be cleared in 15 minutes without chemicals.

Sink won't drainClogged kitchen sinkSlow drain fixBathroom sink cloggedStanding water in sinkDrain clog

Key takeaway: Kitchen clogs are usually grease; bathroom clogs are hair and soap scum. Start with boiling water, then try a plunger or clean the P-trap. Most clogs clear in under 15 minutes without chemicals.

What's Happening

Debris accumulates in the drain, the P-trap (the U-shaped pipe under the sink), or the horizontal pipe connecting to the wall. Kitchen sinks clog from grease that solidifies in the pipes, food particles, and soap residue. Bathroom sinks collect hair, toothpaste, and soap scum. The deeper the clog, the harder it is to reach with basic tools.

What to Check

Try boiling water first. Boil a full kettle and pour it directly down the drain in two or three stages, waiting a few seconds between pours. This dissolves grease and soap buildup. Do not use on PVC pipes if water is standing — use hot tap water instead.
Remove visible debris. Pull out the drain stopper or strainer. Use a flashlight to look down the drain. Pull out any visible hair or gunk with needle-nose pliers or a Zip-It tool (a $3 barbed plastic strip).
Try baking soda and vinegar. Pour half a cup of baking soda down the drain, followed by half a cup of white vinegar. Cover the drain and wait 15-30 minutes. Flush with hot water. This breaks up organic clogs without harsh chemicals. Important: never combine vinegar with chemical drain cleaners like Drano — this can create toxic fumes.
Use a plunger. Use a flat-bottomed (cup) plunger, not a flange plunger. Fill the sink with a few inches of water. Place the plunger over the drain, creating a seal. Pump vigorously 15-20 times. The pressure dislodges clogs in the P-trap.
Clean the P-trap. Place a bucket under the P-trap. Unscrew the slip nuts by hand or with pliers. Remove the U-shaped section and clean it out. Check for clogs in the horizontal pipe going into the wall. Reassemble hand-tight.

DIY Cost

$0–15

Pro Cost

$150–300

Call a Pro If

Multiple drains in your home are clogged simultaneously (main sewer line issue)
Water is backing up into other fixtures when you run the sink
You've tried all methods above and the clog persists (deep clog in wall pipe)
There's a foul sewage smell coming from the drain

Frequently Asked Questions

Can I use Drano or chemical drain cleaners?

They can work on minor clogs but damage pipes over time, especially older metal pipes. Boiling water, baking soda and vinegar, or a plunger are safer and usually just as effective.

Why does my sink keep clogging?

Recurring clogs usually mean grease buildup or a partial blockage deeper in the system. Pouring boiling water down the drain weekly prevents most buildup.

When should I call a plumber for a clogged sink?

Call if multiple drains clog at once, water backs up into other fixtures, or you've tried all DIY methods and the clog persists.

Why does my sink drain slowly but not completely stop?

A slow drain means a partial blockage — usually grease buildup in a kitchen sink or hair and soap scum in a bathroom. Boiling water poured slowly down the drain dissolves grease; a drain snake or zip-it tool pulls out hair. A slow drain almost always becomes a full clog within weeks if not treated.

Is it safe to use baking soda and vinegar to unclog a drain?

Yes — it's safe on all pipe types including PVC and older metal pipes. Pour half a cup of baking soda down the drain, follow with half a cup of white vinegar, cover the drain for 5 minutes, then flush with hot water. It works well on light clogs and grease buildup, but won't break up a solid hair clog the way a drain snake will.

How much does it cost to unclog a sink?

DIY methods cost nothing to $30 (a drain snake). A plumber for a simple sink clog runs $100–$250. If the clog is deep in the main line requiring hydro-jetting, expect $300–$600. Always try the DIY steps first — most household sink clogs clear without professional help.

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