How to Unclog a Bathtub Drain With a Plunger

Project Overview
  • Working Time: 10 - 20 mins
  • Total Time: 10 - 20 mins
  • Skill Level: Beginner
  • Estimated Cost: $0 to $20 (if tool purchase needed)

Next to the kitchen sinkgarbage disposal, and toilet drains, the tub drain gets the most abuse of any drain in the home. We load it up with hair, soap, and hair care products, along with the occasional shampoo bottle cap. Over time, the drain gradually clogs until you find yourself standing in the tub taking a shower with several inches of dirty water lapping at your ankles.

Plunger laying next to bathrub drain for unclogging

The Spruce / Michelle Becker

You can easily unclog your bathtub drain with a standard cup-style plunger, but you have to seal the overflow drain first. Tubs essentially have two drains: There's the familiar one at the bottom of the tub that you close to fill up the tub with water. But there's also one higher up on the front wall of the tub in line with the faucet spout and the bottom drain. This is called the overflow drain.

Before Getting Started

You may never have noticed the overflow drain because many of them look like a solid metal disc rather than a perforated drain cover. But if you look under the bottom edge of the disc, you'll see that it has an opening. This is a secret passage where the water can go if you accidentally overfill the tub. Some overflow drains have visible holes or other features, but they all do the same thing.

The water entering the overflow drain goes into a pipe that feeds into the main tub drain. This presents a problem when you need to plunge the tub. Plungers work on suction power, and the overflow drain (which doesn't close, for obvious reasons) acts as a big air vent that kills the suction. Therefore, you must seal the overflow opening before getting to work with the plunger. The best way to seal an overflow is by covering it with duct tape.

What You'll Need

Equipment / Tools

  • Cup-style plunger

Materials

  • Duct tape

Instructions

Plunger and roll of duct tape to unclog a bathtub drain

The Spruce / Michelle Becker

  1. Prepare the Tub

    Tear off a piece or two of ordinary duct tape, and completely cover the overflow opening, making sure to seal the edges of the tape against the surface of the tub.

    Remove the stopper of the bottom (main) tub drain. You may have to unscrew it or turn it back and forth a little while pulling up.

    Fill the tub with about 1 to 2 inches of hot water (not cold). Hot water helps dissolve soap in clogs.

    Piece of duct tape covering overflow opening to prepare tub

    The Spruce / Michelle Becker

  2. Position the Plunger

    Place the cup plunger over the drain, so the entire lip of the cup seals against the tub surface. The cup seal is critical because that's what creates suction and loosens the clog with the action of the plunger.

    Plunger cup placed over drain opening closeup

    The Spruce / Michelle Becker

  3. Plunge the Drain

    Using quick, forceful strokes, push the plunger down, then pull up, repeating five to six times. Maintain the cup seal throughout the five or six strokes, and then pull the cup all the way up and off of the drain with the last stroke. Pumping the plunger forces water down into the pipe, then sucks it back up, forcing the clog up and down along with the drain water, ultimately breaking it up.

    Repeat the same process as needed until the drain starts to flow freely.

    Plunger stroked up and down in bathtub filled with water

    The Spruce / Michelle Becker

  4. Remove the Tape

    Remove the duct tape from the overflow and replace the drain stopper.

    Tip

    If plunging several times does not clear the clog, remove the stopper assembly (as needed) and snake the drain through the overflow drain opening.

    Duct tape removed from overflow opening

    The Spruce / Michelle Becker