What to Do When Your Tub Won’t Drain

By Amanda Lutz

Apr 10, 2023
Stylish corner oval bathtub filled with fresh clean water in a brown tile surround flanked by two windows, overhead view

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There’s nothing more inconvenient than a tub that won’t drain, and it’s a problem that most homeowners encounter. There are a few common causes for this—such as hair clogs, soap scum, or damaged drain pipes—but it needs immediate attention, either by troubleshooting yourself or calling a professional plumber.

We’ll cover why your bathtub won’t drain, the steps you should take to solve the issue, and what to do if you can’t resolve your drain problem on your own.

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Reasons Why a Tub Won’t Drain

One of the most common plumbing problems people face is a bathtub that won’t drain. This can happen for several reasons, and getting to the bottom of it is essential before proceeding with any unclogging attempts.

1. Hair Blockages

Hair is the most common reason behind a clogged drain. It’s normal to lose between 50 to 100 strands of hair each today, and this number could be higher on days you wash your hair.

When hair goes down the drain, it can stick to the pipes. Over time, hair, along with soap scum and other gunk, accumulates and clogs the pipes. This prevents water from passing through.

2. Soap Scum

Soap scum, also called lime soap, is a combination of soap talc, minerals, dead skin, and body oils that forms a film and sticks to the sides of your bathtub and pipes. Soap scum is challenging to remove and even more complicated when it’s in a hard-to-reach area like your bathroom’s plumbing.

Over time, soap scum collects on the sides of pipes and traps hair, dirt, and other debris. If you have hard water, calcium and magnesium react with soap scum to form insoluble clogs.

3. Dirt and Grime Buildup

When you bathe, dirt, grease, and bath and beauty products wash off and go down the drain. Ingredients in shampoo, conditioner, body wash, and some bath bombs can harm your bathroom’s plumbing. Over time, this debris collects inside your shower drain and prevents water from passing through.

4. Hard Water

If you’ve noticed white or yellow flaky buildup around your fixtures, that’s hard water. 

Hard water has a high concentration of calcium and magnesium, which isn’t good for your pipes. Mineral deposits—or limescale—will form along the pipes, narrowing their openings and reducing water flow. Ultimately, water pressure will decrease and your tub won’t drain properly. Further, hard water can lead to pipe corrosion, which also causes drainage problems.

5. Problems with the Built-In Stopper

Some tubs have built-in drain stoppers that control water flow and stop it from draining out of the bathtub. Over time, they can become worn out, damaged, or stuck shut due to hair, soap, and debris buildup in the stopper mechanism.

 


 

Steps to Unclog a Tub Drain

Some blockages can be fixed without calling the plumber. Follow these drain cleaning steps to fix a tub that won’t drain.

Step 1: Clear Out Hair and Other Blockages

Empty the tub of any standing water and remove the drain stopper. Every tub drain is different, so follow the manufacturer’s instructions on how to remove yours. Clear the stopper and drain cover of any visible hair and debris and place it back into the tub.

Step 2: Pour Boiling Water Down the Drain

Boiling water can sometimes clear the buildup of grease, soap, and other residues in your drain. This may be an easy fix, but only attempt it if your pipes are metal. Pouring boiling water down PVC pipes could damage them.

Fill a pot or kettle with water and heat it until it’s boiling. Next, slowly pour the hot water down the drain until the container is empty. Wait 10 minutes, then turn on the faucet to see if the drain is clear. Repeat this a couple of times if necessary.

Step 3: Use Baking Soda and Vinegar

Combining baking soda and vinegar produces bubbles of carbon dioxide gas, which can sometimes help to break apart minor clogs.

Mix equal parts baking soda and vinegar—about one-third cup each—in a measuring cup, then quickly pour it down the clogged drain. Let it sit for about an hour, then run hot water down the drain to flush it out.

Step 4: Use a Wire Coat Hanger

If you don’t have a plumbing snake, a wire coat hanger is the next best thing to remove stubborn blockages

Use a screwdriver or pliers to remove the drain cover. Find a wire coat hanger, straighten it out, and create a hook on one end. Push the end with the hook into the drain opening until you feel some resistance, which is the clog. Use the hook to pull out whatever is blocking the flow of water.

After you’ve cleared out as much debris as possible, pour a pot full of boiling water down the drain and wait 10 minutes before turning on the bathtub faucet.

Step 5: Get the Plunger

You can use a plunger on your bathtub drain similarly to how you would with your clogged toilet. Fill your tub with water and place the plunger over the drain. Then, push the plunger down and pull it up again quickly several times. If this works, the clog will clear and water will immediately drain from the bathtub. Try this several times if the tub won’t drain right away.

Step 6: Try a Plumbing Snake

If nothing has been successful, it’s time to use a plumber’s snake, which you can get at a hardware store or home improvement center. A plumbing or drain snake is a long, flexible metal cable with a coil or auger at the end. They’re more powerful than most other methods but can be tricky to use.

Use a screwdriver to remove the drain cover and push the snake into the drain. Push the snake as far as it will go until you feel some resistance. Wiggle and twist the end, then pull it out to clear the drain. Repeat this process until the tub drain is clear.

 


 

Use Caution With Chemicals

Chemical drain cleaners are another popular clog-removal method. When you use a drain cleaner such as Drano, a chemical reaction occurs in your plumbing that breaks down the hair, soap scum, or debris blocking the pipe. A common problem with this DIY method, though, is misusing or combining chemicals.

The ingredients in liquid drain cleaners can damage your pipes and septic tank, especially if they’re used regularly. Another dangerous situation is when frustrated homeowners try multiple chemicals to clear an obstruction. Combining multiple common household chemicals, such as bleach and ammonia or sodium hydroxide, can be deadly.

To avoid potential issues, use a combo of the natural solutions detailed above when your tub won’t drain. For stubborn clogs, call a professional plumber.

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What to Do If Troubleshooting Doesn’t Work

When you’ve tried everything and the tub still won’t drain, contact a professional plumber and describe the situation. They’ll want to know what you’ve done about the issue before you called them. Tell the plumber the troubleshooting steps you’ve taken and that nothing will work.

 


 

How to Hire a Professional

Before you pick up the phone, here are a few tips on how to hire a professional plumber:

When you find a reputable plumber, they’ll schedule an inspection and give you a detailed estimate. Most pros offer free estimates, so get several quotes and detailed cost breakdowns.

Another consideration is a home warranty for plumbing problems. If you have a home warranty plan that covers your home’s plumbing system, then your provider will send a vetted professional to fix your drainage problem.

 


 

Our Recommendation

When your tub won’t drain, we recommend trying DIY troubleshooting steps—boiling water, baking soda and vinegar, plunging, and a plumbing snake—and avoiding harsh chemicals. When misused, liquid drain cleaners can damage your pipes or cause you harm. 

If all else fails or you feel uncomfortable doing it yourself, hire a professional plumber to get the job done.

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Tub Won’t Drain FAQ

What causes water to come up through a tub drain?

Water coming back up through a tub drain is never a good sign. This can happen due to a blockage in your home’s plumbing system or an issue with the city’s sewer pipes.

How do I know if my bathtub is clogged?

If your tub won’t drain or drains slowly, your bathtub is likely clogged. You can attempt to clear the blockage yourself or call a professional plumber.

Is it normal for a bathtub to take a long time to drain?

A slow-draining bathtub is often caused by the accumulation of hair, soap scum, dirt, and other debris caught in your bathroom’s plumbing.