How to Use a Plunger to Unclog a Sink Drain

Woman wearing yellow dish gloves to unblock sink using plunger, close-up
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A clogged sink drain is one of the most common plumbing problems. It's also one of the easiest DIY repairs. The first step is make sure you have the right type of plunger. A standard cup-style plunger is made for sinks. These have a shallow dome with a flat bottom rim that seals to the sink basin around the drain hole. By contrast, a toilet plunger has a tall dome and a flange, or collar, that extends from the bottom edge.

The flange helps seal around the hole in the toilet bowl. You can use a toilet plunger on a sink only if you tuck the flange up into the dome; otherwise, it won't seal to the sink basin.

Check the Stopper First

If it's your bathroom sink that's clogged, clearing it may be as simple as pulling out the pop-up stopper and cleaning it off. Hair, soap, and other gunk tend to collect on the stem below the stopper's plug as well as on the rod that moves the stopper up and down (it extends into the middle of the drain pipe). Use needlenose pliers or a metal coat hanger bent into a hook to grab hair from these parts. If that doesn't clear the drain, move on to plunging.

How to Plunge a Sink Drain

Plunging a drain uses the forces of suction and compression. When you pull up on a plunger, it pulls water in the drain upward, helping to loosen the clog. When you push down on the plunger, water is forced downward, forcing the clog in the other direction.

This push-pull effect breaks up and loosens the clog so the water in the drain can carry it down through the drain system (and out of your life). Keep the two forces in mind when plunging your drain:

  1. Block the overflow drain opening on a bathroom sink by plugging it with a wet rag. For a two- or three-compartment kitchen sink, block the drain openings of all but the basin where you will plunge. This is necessary to create suction and compression in the drain line; without it, the plunging will have very little effect.
  1. Place the plunger cup over the drain opening so it covers the opening fully. Run a small amount of water in the sink—enough to cover the cup of the plunger.
  2. Thrust the plunger in an even up-and-down motion. The suction force of the upstroke is just as important as that of the downstroke. Keep the seal between the rubber plunger cup and the sink surface intact. You may actually be able to feel the moment when the clog loosens, as the plunger handle may suddenly get easier to pump.
  3. Pull the plunger away from the drain opening after about six pumps of the plunger, and see if the water drains away. If it does, you have successfully loosened the clog. If not, then repeat the process.
    Tip: If you're having difficulty getting a good seal between the plunger cup and sink basin, apply some petroleum jelly around the cup.
  4. Run a lot of hot water after the clog is cleared to flush any debris on into the main drain line. This can help prevent a new clog from forming.

If the drain isn't clear after several attempts at plunging, the next step is to snake the drain. But in a surprising number of cases, you will have cleared your clogged drain without even getting your hands dirty.