Around the house · Easy · about 15 minutes

Unclog a Sink or Toilet

Clogs happen in every home. A plunger clears most sink and toilet clogs in a few minutes, with no chemicals. Knowing which plunger to grab, how to get a good seal, and when to stop saves a mess and sometimes a service call.

When to teach it: Watch from about 6, help from about 9, do it alone from about 11.

🔬 The physics behind it

Cup plungersinks, tubs, showersFlange plungertoilets
Cover the cup with water, seal it over the drain, then push smoothly and pull sharply.

You'll need

  • Cup plunger (a plain rubber cup) for sinks, tubs, and showers
  • Flange plunger (a cup with an extra rubber sleeve) for toilets
  • Rubber gloves
  • Old towels or rags
  • A bucket
  • Hand drain snake (optional)

Before you start

  • If the toilet bowl is full and not draining, don't flush again. It can overflow.
  • If someone has already poured a chemical drain cleaner into the drain, don't plunge it and don't add any other product. Call a plumber.

Step by step

Tick each step as you go if you like; ticks stay on this device.

Physics

How it works: Why a plunger works

Pressure is force spread over an area. When you push a plunger down, your force presses on the water trapped under the cup.

Water is very close to incompressible, which means it barely squeezes smaller. Instead of shrinking, it passes the push along. Pascal's principle says a change in pressure in one part of a fluid travels through all of it. So your push travels down the pipe to the clog. Pulling up sharply tugs the other way, rocking the clog back and forth until it breaks loose.

That's why the seal and the water matter. Air squeezes easily, so a cup full of air just squishes. And if the overflow hole is open, the push escapes out of it instead of reaching the clog.

pressure = force ÷ area (P = F ÷ A)

Try it: Fill a plastic bottle to the very top with water, cap it, and squeeze. Then pour out half, cap it again, and squeeze. The half-full bottle squishes easily because air compresses. The full one pushes back because water doesn't.

Keep learning: Science

Teaching it to your kids

  • Show your child the two plungers and let them pick the right one for each job.
  • Practice on a slow sink first. It's less messy than a toilet.
  • Talk about what never goes down a toilet: dental floss, hair, gum, and anything that isn't toilet paper.
  • Keep a plunger near each toilet so no one has to hunt for one in a hurry.

Tips

  • Keep a cover or strainer over sink and tub drains to catch hair and food bits.
  • Never pour grease down a drain. Let it cool in a can, then put it in the trash.
  • Clean hair out of the tub drain after washing your hair.
  • Wear rubber gloves and lay an old towel around the base. It can get messy.

Common mistakes

MistakeInstead
Flushing a clogged toilet again to 'push it through'.Don't. If the water is high and not draining, another flush can overflow the bowl. Plunge instead.
Using a cup plunger on a toilet.Use a flange plunger. Its rubber sleeve seals in the toilet's drain.
Plunging a sink with the overflow hole open.Plug the overflow with a wet rag so the pressure goes toward the clog.
Mixing drain cleaners, or plunging after using one.Never mix products, and never plunge a drain that has chemical cleaner in it. Call a plumber.

Safe habits

  • Never mix drain cleaners or other cleaning products. They can react and give off dangerous fumes.
  • Don't use a plunger on a drain with chemical drain cleaner in it.

When to call a pro

  • If plunging and a hand snake don't clear the clog, call a plumber.
  • If water backs up in more than one place, like a toilet or shower when the washing machine drains, the blockage may be farther down the line. Call a plumber.

Sources

Free how-to guides for families, with nothing to earn, pass or send in. They follow U.S. rules and sources; your owner's manual, product labels and state and local rules come first.

@teddyrookbook GitHub