How to fix a clogged bathtub drain

Next to the kitchen sink, garbage 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.

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.

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.

The Spruce / Michelle Becker

  1. 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.

    The Spruce / Michelle Becker

  2. 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.

    The Spruce / Michelle Becker

  3. 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.

    The Spruce / Michelle Becker

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

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

    The Spruce / Michelle Becker

In this video, This Old House plumbing and heating expert Richard Trethewey shows how to fix a slow draining tub.

  1. Unscrew the overflow plate from the end of the tub. Use pliers, if necessary, to pull the plate, linkage rods and stopper out from behind the tub.
  2. Feed a drain snake down the overflow hole. Tighten the thumbscrew to lock the snake in place, then crank the handle and push the snake down the drain. Repeat two or three more times, extending the snake further down the drain each time.
  3. Turn on the water and check to see if the tub is draining any better.
  4. Work the drain snake down the overflow hole, only this time, allow the water to run while you snake out the drain.
  5. With the clog cleared, inspect the stopper at the end of the linkage rod. If it appears that the stopper was sitting too low in the drainpipe, raise it by turning the rods to shorten the linkage. Tighten the lock nut to secure the stopper.
  6. Reinstall the stopper and linkage and screw the overflow plate to the end of the tub.

How to fix a clogged bathtub drain

We get a call every month about a pesky bathtub being clogged with too much hair. This is a problem for many homeowners because it is usually accompanied by the unintended effect of pooling water. Standing water is the definition of a standard plumbing issue; we cannot ignore it because we step it in every day when we attempt a morning or afternoon shower.

The water is disgusting, and it comes with health concerns too when water pools for that long. Bacteria starts to grow; mosquitoes use it as a breeding ground, and it might even smell as it collects all your soap and shampoo residue. This is a problem, you can solve this using a chemical drain cleaner, but we understand many people are not comfortable with pouring random chemicals into their drains.

While using chemical drain cleaners might work to unclog your drain problem, there is also a risk of harming your plumbing pipes when choosing this method. Benjamin Franklin Plumbing has a simple solution you can try first before you reach for the chemical cleaners or reach for your phone to call a professional.

We do however recommend you call a professional if the clog persists, as continually trying to fix a clog might cause more a bigger clog or permanent damage to your residential piping. So, our method is simple; it is broken down into steps, and it uses everyday items like vinegar, hot water, and baking soda. This is close to an old elementary school experiment, and you might even find yourself having fun in the process.

Items needed to make a DIY home remedy drain cleaner

  • Kettle of boiled water – about 3 cups
  • Half a cup of baking soda
  • One cup of vinegar
  • Timer

What you will need to do

First thing is first, make sure you have your bathtub drained before you start. Use cups or buckets to remove the standing water from your tub and then proceed to the steps to relieving your bathtub clog.

After you have everything prepared, take the following steps to resolve your clog.

  1. Pour 1 cup of water down your drain
  2. Put the half cup of baking soda down the drain
  3. Mix in the vinegar with your second prepared cup of water
  4. Pour in the vinegar/water mixture down the drain with the added baking soda – Things will begin to bubble/fizz, this is good, it means things are working!
  5. Cover the drain to allow the chemistry to take place between the vinegar and the baking soda
  6. Set the timer for 10minutes to allow the formula to take care of your clog
  7. Pour another cup of boiled water down your drain to flush out the remaining clog

You have followed the above steps, and you can now check up on your drain. Run water and see if water is still pooling in your bathtub. If this treatment worked then congratulations! You did a great job in fixing your drain, and this method can be reapplied to your kitchen sink, bathroom sinks, and any other fixture that uses a drain.

Why should you not resort to using bleach to unclog your bathtub drain?

We do not suggest pouring bleach down your drain as it will kill both good and bad bacteria. Pouring bleach down your pipes is also bad for the piping and wears them down making them weaker and reducing their long life spans. Look for more natural based drain cleaners to fix your clogs. Enzyme-based drain cleaners work well.

Call Benjamin Franklin Plumbing Bay Area today to learn more about how to unclog pesky drains. We are happy to do a full inspection of your plumbing system, resolve your plumbing issues, and provide you with advice on how to preserve your plumbing for years to come so repairs will be limited.

Call: 415-642-4164
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