How to Unclog a Sink: 8 Best Methods

Occasional clogs in the sink, tub, or shower drain happen. Luckily, it's easily to unclog them with the right tools and cleaners. They are usually caused by localized clogs in the drain trap or branch drain for a single fixture. However, if you have several fixtures that are draining slowly or not draining at all, the problem may be in the main drain or sewer line in your home. Soap scum, hair, and food scraps are just some of the things that may cause clogs.

There are multiple ways to unclog a sink drain, and the choice of method depends on the severity of the clog and its cause. For stubborn clogs, using a plunger or a sink auger might be necessary. In case of a simple soap scum build-up, a solution of baking soda and vinegar, or another non-toxic and biodegradable drain cleaner, can be effective.

Read on for details and tips for each of these methods and more.

8 Ways to Unclog a Bathroom Sink

Boiling Water

Most clogs in sinks and tubs are due to a combination of hair, grease, soap residue, and tepid water that is trapped in the drain trap right below the drain opening. If you have metal pipes, you can first try to loosen the clog with boiling hot water. Pouring a pot of boiling water directly down the drain into the trap may dissolve the clog, especially if it consists of soap scum or grease. Hot tap water won't do the trick—it has to be boiling water.

• Boil a gallon of water in a large pot kettle or something that allows you to pour it directly into the drain.
• Wait for a rolling boil and carefully carry it to the clogged sink.
• Pour the water slowly into the drain being careful not to splash as this can lead to burns.
• Give it a few minutes to dissolve the clog.

Baking Soda and Vinegar

If simply boiling water isn't enough or you have plastic piping, a combination of baking soda and vinegar can also be effective. This is especially true on minor clogs such as soap residue or toothpaste. Make sure to remove any standing water caused by the clog before beginning.

• Measure 1/2 cup baking soda and 1/2 cup vinegar and pour each down the clogged drain.
• Place a cloth or plug on the drain to cover the opening.
• Wait about 30 minutes to an hour before removing the cover from the drain.
• Flush the drain with boiling water and flush again with tap water to see if the sink now drains.
• Repeat if necessary.

Baking Soda and Salt

Baking soda is also an excellent remedy for breaking down sink clogs such as those formed by grease. Here's how:

• Mix equal parts of baking soda and salt with four parts of boiling water.
• Pour the baking soda and salt mixture directly down the drain.
• Allow it to work for several hours or overnight.
• Flush your drain with hot water the next morning to ensure the drain is clear.

Plunger

It may be that simply flushing the drain doesn't do the trick. In this case, two types of drain plungers are common for home use: the cup plunger and the flange plunger (also called a toilet plunger). For working in sinks, showers, and tubs, use a cup plunger. Before using the plunger, seal the overflow opening. On a bathtub, apply duct tape over the overflow at the front of the basin. In a sink, seal the overflow outlet found at the top of the bowl by covering with a piece of duct tape or stuffing it with a damp rag.

• Lift out the removable basket strainer in the kitchen sink drain or the drain stopper in a bathroom sink drain.
• Fill the sink bowl, tub, or shower pan with several inches of water. This will allow the cup of the plunger to form a tight seal.
• Place the cup plunger over the drain opening and make sure it has a good seal against the surface around the drain.
• Use quick, sharp plunges, pumping up and down several times to attempt to clear the obstruction. You may need to hold your hand over the duct tape or wet rag sealing the overflow opening—the air pressure caused by the plunging motion may cause the tape to loosen.
• Let the faucet run for a minute or two after the drain is clear.
• Remove the overflow outlet seal and replace the drain stopper or sink basket.

Sink Auger

If the plunger did not clear the clog, try a sink auger (also called a drum or canister auger or a drain-cleaning snake.)

• Remove the drain stopper, as applicable.
• Extend the auger cable into the drain opening. When you feel it bump up against the clog, pull out about 12 inches more of the cable and tighten the setscrew on the auger canisters.
• Turn the crank handle of the auger clockwise while applying moderate pressure on the cable. The cable end may get stuck on the clog or bends in the pipe; turning the cable helps break up the clog or get the cable end past the bend.
• Extend more cable as required until you feel you've worked through the clog. This should work if the clog is in the trap.
• Pull the cable out of the pipe, pushing it back into the canister as you go. The cable may have a large hair clog stuck to its end when it comes out of the drain. Repeat the process as needed until the clog is cleared.
• Flush with hot water from the faucet once the drain starts to flow.
  

P-Trap Cleaning

If you have extended the cable of a sink auger all the way through the trap without contacting a clog, then the clog is probably in the branch drain or the vertical drain stack in the wall past the branch drain. To get at these pipes, you'll have to remove the drain trap. For clogs beyond the trap, getting to them is a bit more work but is still fairly easy.

• Place a bucket under the trap to catch the water that will come out once the trap is removed.
• Loosen the slip nuts at each end of the trap with tongue-and-groove pliers or a pipe wrench. Remove the slip-nuts and the trap. Note how the nylon slip washers are oriented on the pipe, to make reassembly easier.
• Dump the water in the trap into the bucket. Water will also drain from the disconnected ends of the pipe.
• Insert the auger cable into the horizontal section of the drainpipe, tighten the setscrew, and crank the cable, as before. If the end of the cable gets stuck at a pipe bend, cranking the auger and applying pressure will help get it past the bend.
• Work the cable farther into the drain until you feel you've worked through the clog, then remove the cable.
• Reassemble the drain trap and flush the drain with hot water from the faucet to clear any remaining debris.

Enzyme Drain Cleaners

If all else fails and you want to use a drain cleaner, opt for a mild, non-toxic, and biodegradable drain cleaner. Do not use chemical drain cleaners. They may cause damage to the environment or the drain pipes in your plumbing system, and these caustic chemicals can be very dangerous to use. In addition to their danger, chemical cleaners rarely work on stubborn clogs. Furthermore, after they fail, you will be left with a sink full of water and toxic chemicals that you must bail out by hand. Follow the instructions on the non-toxic cleaner of your choice for best results.

Wet Dry Vacuum

A wet dry vacuum is another surprisingly simple way of unclogging drain. It works similar to a plunger but with more power and suction. After removing the drain stopper, follow these steps.

• Cover the opening of the drain with a rag and seal the overflow with an additional damp cloth.
• Place the end of the hose of the vacuum against the drain to make a tight seal.
• Start the vacuum and listen for changes in sound. Switch to suction after 15 seconds if there is no change and then switch back to exhaust.
• Flush the drain with water to make sure it is now clear.

When to Call a Professional

It may be that a severe clog cannot be cleared with any DIY methods. If that's the case, it's best to call a licensed plumber to fix the problem. If you continue to notice slow drainage or foul odors emitting from the drain, this could be a sign of a longstanding buildup that will continue to block the water. It's best to call a reliable pro at this point to solve the problem once and for all.