How to Unclog a Sink Drain

Easy Methods for Kitchen & Bathroom Sinks

Project Overview
  • Working Time: 30 mins - 1 hr
  • Total Time: 1 hr
  • Skill Level: Beginner
  • Estimated Cost: $0 to $30

Occasional clogs in the sink, tub, or shower drains are a fact of life. 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.

How to Unclog a Sink Drain

The Spruce / Hilary Allison

Here's how to unclog a sink using several methods:

  • Use a plunger.
  • Try a sink auger.
  • Remove the drain trap to auger the branch drain.
  • Use a mild, non-toxic, and biodegradable drain cleaner.
  • Try a baking soda and vinegar solution.

Read on for details and tips for each method.

Try Using Boiling Water to Fix a Clogged Sink

Most clogs in sinks and tubs are due to a combination of hair, grease, soap residue, and tepid water that are trapped in the drain trap right below the drain opening. If you have metal pipes, you can try to loosen the clog with hot water—very hot. 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 or tea kettle. Something that will allow you to pour directly into the drain, such as a tea kettle, is best. When it's at a rolling boil, carefully carry it over to the clogged sink. Pour the water slowly into the drain. Be careful not to splash the water, as this can lead to burns. Give it a few minutes to dissolve the clog. If it doesn't work, proceed to the steps below.

Warning

Do not pour the boiling water directly into a porcelain sink, but only down the drain. And do not use boiling water if you have plastic (PVC) pipes since water hotter than 140 degrees Fahrenheit can soften some types of PVC pipe. For plastic pipes, attempt to clear the clog using a plunger.

person using vinegar to unclog a sink

The Spruce / Ana Cadena

What You'll Need

Equipment / Tools

  • Pot or tea kettle (for boiling water)
  • Cup drain plunger
  • Sink auger (for stubborn clogs)
  • Tongue-and-groove pliers (if needed)
  • Bucket (if needed)

Materials

  • Duct tape (or rag)

Instructions

Materials and tools to unclog a sink

The Spruce / Kevin Norris

How to Unclog a Sink Using a Plunger

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.

  1. Prepare for Plunging

    If you are working on a bathroom sink, seal the sink overflow outlet found at the top of the sink bowl, just under the rim. Cover the hole with a piece of duct tape or stuff it with a damp rag.

    If you are working on a bathtub, apply duct tape over the overflow opening at the front of the tub.

    If the clog is in a kitchen sink, lift out the removable basket strainer. If the clog is in a bathroom sink, remove the drain stopper. Try lifting it out or turning and lifting.

    Sink overflow outlet sealed with duct tape

    The Spruce / Kevin Norris

  2. Fill With Water

    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.

    Sink bowl filled with water

    The Spruce / Kevin Norris

  3. Seal the Plunger

    Place the cup plunger over the drain opening and make sure it has a good seal against the surface around the drain.

    Cup plunger placed over drain opening in water-filled sink

    The Spruce / Kevin Norris

  4. Use Your Plunger

    Using quick, sharp plunges, pump 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.

    Plunger pushed up and down to clear obstruction in sink

    The Spruce / Kevin Norris

  5. Run the Water

    Let the faucet run for a minute or two after the drain is clear.

    Sink faucet running with water to clear drain

    The Spruce / Kevin Norris

  6. Replace the Stopper

    Remove the overflow outlet seal and replace the drain stopper or sink basket.

    Duct tape removed from overflow opening

    The Spruce / Kevin Norris

Use a Sink Auger for Stubborn Clogs

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

  1. Remove the Stopper

    Remove the drain stopper, as applicable.

    Drain stopper removed from sink

    The Spruce / Kevin Norris

  2. Insert the Auger

    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.

    Auger cable inserted into sink drain opening

    The Spruce / Kevin Norris

  3. Turn the Auger Handle

    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.

    Auger handle turned clockwise applying pressure to cable

    The Spruce / Kevin Norris

  4. Extend the Cable as Needed

    Extend more cable as required until you feel you've worked through the clog. This should work if the clog is in the trap.

    Auger cable extended to work clog in drain

    The Spruce / Kevin Norris

  5. Remove the Auger From the Drain

    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.

    Auger cable removed from sink drain to remove clog

    The Spruce / Kevin Norris

  6. Run the Water

    Flush with hot water from the faucet once the drain starts to flow.

    Water running from sink faucet with clear flow

    The Spruce / Kevin Norris

If you have extended the cable 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.

Remove the Drain Trap to Auger the Branch Drain

For clogs beyond the trap, getting to them is a bit more work but is still fairly easy.

  1. Place the Bucket

    Place a bucket under the trap to catch the water that will come out once the trap is removed.

    Bucket placed under drain trap to catch water

    The Spruce / Kevin Norris

  2. Remove the Slip Nuts and Drain Trap

    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.

    Slip nuts loosened from drain trap with tongue-and-groove pliers

    The Spruce / Kevin Norris

  3. Dump the Water

    Dump the water in the trap into the bucket. Water will also drain from the disconnected ends of the pipe.

    Water dumped from trap into bucket

    The Spruce / Kevin Norris

  4. Insert the Auger

    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.

    Auger cable inserted into drain pipe

    The Spruce / Kevin Norris

  5. Extend the Cable as Needed

    Work the cable farther into the drain until you feel you've worked through the clog, then remove the cable.

    Auger cable extended inside drain pipe

    The Spruce / Kevin Norris

  6. Replace the Drain Trap and Flush

    Reassemble the drain trap and flush the drain with hot water from the faucet to clear any remaining debris.

    Drain trap reassembled under sink

    The Spruce / Kevin Norris

What About Chemical Drain Cleaners?

If all else fails and you want to use a drain cleaner, opt for a mild, non-toxic, and biodegradable drain cleaner. You can also try a baking soda and vinegar solution.

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. And after they fail, you will be left with a sink full of water and toxic chemicals that you must bail out by hand.