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How to Unclog a Toilet

A clogged toilet is one of the most common and stressful problems people have to deal with in their homes. If not cleared swiftly and properly, it can become a big mess, possibly spilling onto the bathroom floor and leaking through to the rooms below. In this video, This Old House plumbing and heating contractor Richard Trethewey explains how to unclog a toilet.

Fortunately, a clogged toilet is almost always an easy thing to fix. There are a few reliable options for clearing a clogged toilet—including using a plunger, a toilet auger, and even a simple bucket of soapy water—and we’ll walk you through the right way to use each method.

Steps for Unclogging a Toilet

Step 1: Prepare the toilet for the job

  • First off, if you just flushed your toilet and it’s about to overflow because it’s clogged, you may have a chance to stop it from spilling over onto your bathroom floor by quickly lifting off the tank lid and reaching down to close the flapper valve before the whole tank empties.
  • It’s also a good idea to quickly close the supply valve where the water line connects behind the tank, particularly if pushing the flapper in the tank down doesn’t stop the flow of water into the bowl.
  • Reach down and turn the knob on the valve clockwise to shut it off.

Step 2: Remove water if the toilet bowl is full

  • If the clogged toilet has filled to the top of the bowl, you will need to remove some of the water before proceeding, so you don’t splash any onto the floor. To do this, first put on some long rubber gloves and grab a small pail and a bucket; a large yogurt container and an old spackle bucket would do the trick.
  • Then use the pail to bail water into the bucket until the water in the toilet is down to its normal level—about half full. Now it’s time to tackle the blockage.

Step 3: Clear a toilet blockage with a plunger

  • The most obvious way to fix a clogged toilet is to use a plunger. The key to success with this method is to have both the correct type of plunger and an effective technique.

Choose the Right Plunger

Three common plungers work well for clearing a toilet: the flanged-cup style, the beehive style, and the accordion or bellows style.

Any of these will work well, but the best plungers are ones with enough volume to force plenty of water down the drain and soft enough to conform to the curves of the toilet bowl and make a good seal.

You don’t want to use one of those small, hard rubber plungers meant for clearing sinks and tubs, because they don’t have enough volume to force water through the long drain trap on your toilet.

How to Use a Toilet Plunger Correctly

For a plunger to provide enough force to clear a blockage, it has to push water, not air. So dip the end of your plunger into the toilet bowl at an angle and scoop some water into it; if you lower the plunger into the water with the handle straight up and down, there will only be air inside.

Next, press it straight down so that the entire rim of the plunger contacts the bowl. Then, quickly thrust the plunger up and down several times, being careful not to push too violently, which might splash water out of the bowl. The thrusting action is effective because it alternates between pushing and pulling water through the narrow trap, causing the obstruction to loosen and pass down the drain.

This Old House plumbing and heating contractor Richard Trethewey says he has good success with firmly depressing a plunger against the bottom of the bowl and then just using a quick pulling motion instead of an up-and-down motion. He finds that the downward plunging sometimes compresses the blockage deeper into the narrow drain trap instead of clearing it. You can try either method and see which works best for you.

After plunging, it’s time to see if the job was successful. Flush the toilet and watch the water go down the drain—but be prepared to quickly lift the tank lid off and press the flapper valve down to prevent the toilet from overflowing if it hasn’t cleared. Repeat the steps above a few times if you weren’t successful the first time, but if the problem persists, it’s time to move on to the next method.

Note: If you’re determined to get the job done with the plunger, some people claim to have success with pouring a bowl of warm soapy water into the bowl and letting it sit for 15 minutes to help loosen the obstruction before trying the plunger again. But be sure that you don’t use hot water, which could damage the porcelain, causing the toilet to crack.