Is There A Sour Smell In The Bathroom? (We Have a Fix!)

Stacy Randall
by Stacy Randall

After a long workday, you want nothing more than to take a hot shower, until you notice a sour smell in the bathroom. Smelling unpleasant odors is anything but relaxing, and the smells often signal there’s an issue somewhere. Therefore, it’s vital to identify the smell, find the source, and know how to resolve the problem.

A sour smell in your bathroom typically occurs from a build-up of bacteria in the drains, especially if they’re draining slowly. It can also come from bacteria in the p-trap, the U-shaped pipe underneath your sink. To get rid of the sour smell you will need to take a few steps to clean out each drain.

Once you’ve identified the source of the sour smell, the solution can be as simple as cleaning your drains. However, there are many ways to clean out your drains properly.

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The Sour Smell In The Bathroom Is Bacteria

Have you ever left a strand of hair on the side of your tub, then let it wash down the drain? Well, that hair harbors bacteria and takes it into the drain. The hair may even get stuck in the drain and create a clog.

Plus, think about when you take a shower; dry skin is falling off as you wash. All of that organic material is going right down the drain. Dead skin cells are another major cause of bacteria buildup in your drains, leading to a sour smell in your bathroom.

When you have a clogged sink, it drains slowly, causing bacteria to build up in the P-trap. This buildup in the P-Trap creates hydrogen sulfide gas.

This problem can also occur in a sink that you haven’t used recently. Lack of use causes the water in the P-trap to evaporate, no longer stopping gasses from entering your home.

Furthermore, if a drain clogs, it will make it easier for bacteria to settle in the drain. However, the drain does not always have to be clogged to collect bacteria. It’s important to take the proper steps in cleaning out a smelly drain.

How To Clean Your Tub or Shower Drain And Banish The Sour Smell In Bathroom

Properly cleaning your drain is going to be the first step you should take. This will not only get rid of the sour smell in the bathroom but clear out any bacteria as well.

What You Will Need

  • Baking Soda
  • Vinegar (Distilled white vinegar works the best)
  • Boiling Water 

When boiling water on a stove, do not forget to turn the stove off when finished. Always put safety first. Turning the stove off prevents a number of accidents from happening.

Step One: Rinse the Drain

Use the boiling water to rinse out the drain. Slowly pour the water down the drain. This hot water will help loosen and break up any hair follicles.

Step Two: Mix the Ingredients

Start by adding one cup of baking soda to the drain. Afterward, slowly pour in half a cup of vinegar and cover the drain. Let it sit for 15 to 30 minutes.

Step Three: Rinse with Water

Boil a pot of water once again. After it’s boiling, turn the stove eye off and carefully pour the water into the drain.

The boiling water will help push down any leftover residue. It’s a good idea to wear gloves when pouring the water, in case hot water splashes onto your hands or arms.

How To Clean Your Sink Drain And Get Rid Of The Sour Smell

There are a few more steps to cleaning out the sink drain than there is a tub. However, it’s still not difficult and makes for an easy DIY task. To clean the sink drain, you must first remove any hairs.

What You Will Need

  • Baking Soda 
  • Vinegar (you can use lemon juice as a supplement) 
  • Boiling water

Step One: Cleaning Loose Hairs

Loose hairs and toothpaste are the most common types of bacteria build-up in bathroom sinks. Regularly cleaning out the sink stopper can help prevent these build-ups.

Remove the stopper and run warm water over it. Leave the water running for a few minutes to clear the drain.

Step Two: Drain With Water

Pour half a gallon of boiling water down the drain. The hot water will loosen up the debris and make it easier for the baking soda to go into the drain. Also, plunging the drain may help speed up the process.

Step Three: Drain With Natural Ingredients

Natural ingredients can be easier to come by and safer to use. Sometimes the things you need are likely already sitting in your cabinets.

Spoon one cup of baking soda into the drain, making sure it all goes in. Let it sit for just a few seconds. Now, mix in 1 cup of vinegar; white distilled vinegar will work the best.

Cover the drain and mixture immediately as it starts to fizz. Let it sit for one hour to direct the flow of the mixture toward the clogged part of the drain.

Step Four: Repeat Process as Needed

For especially stubborn clogs, you may need to repeat the process a few times to clear the drain.

An Alternative for Natural Ingredients

If you’d rather not use the natural ingredients method, commercial products are available. After rinsing the drain with boiling water, you can use Drano.

You can purchase Drano at most local home stores such as Walmart, Target, and Lowe’s. This product costs anywhere between four to eight dollars.

With that being said, Drano is also known to corrode pipes over time. The long-term use of Drano will eventually cause the pipes to fail. You should not use Drano on metal pipes. It can also potentially eat away at older PVC pipes and black plastic sewer pipes.

Additionally, Drano is also bad for your eyes, skin, and even lungs. Its purpose is to dissolve organic tissue.

If it comes in contact with skin, it is liable to leave a nasty rash. Therefore, always wear safety goggles, gloves, and a mask when handling Drano.

Bacteria In The P-Trap Can Cause A Sour Smell In The Bathroom

The P-trap is a curved piece of pipe commonly found underneath a sink. The bend in the pipe is meant to retain enough water to keep sewer smells from reaching your home. However, this means it also catches hair and debris, clogging and building up bacteria.

How To Clean Your P-Trap And Get Rid Of The Sour Smell In Bathroom

The odd shape can make cleaning the p-trap a bit complicated. It will take a little more time, as there are a few extra steps. Take the time to gather your tools before starting.

What You Will Need To Tackle The Sour Smell In The Bathroom

  • Bucket. This will be beneficial to help keep a huge mess off of the floor. 
  • Wrench/Channel Locks
  • Old toothbrush 
  • Towels. These will help limit mess as well and make clean-up easier. 
  • Old metal clothes hanger. Depending on pipe size, you may have to attach the hanger to a toothbrush. 

Step One: Prep Your Work Space

Place the bucket underneath the sink trap. It will catch the water that leaks once you begin to loosen the nuts.

Keep the towels close by for easy reach. They will help you catch a mess once it starts.

Step Two: Remove The Trap

Using the channel locks, begin to loosen the slip-joint nuts. After a few turns, you should be able to use your hands to finish the job.

When removing the trap, be sure not to lose the O-rings, as they are essential to restoring the piece.

Step Three: Rinse With Boiling Water

Rinse thoroughly with boiling water. This will help loosen and break up any bacteria inside.

Step Four: Scrub With A Toothbrush

Use an old toothbrush to scrub the inside of the P-trap. Use a metal clothes hanger to attach to it if you need more length.

For best results, rinse the pipes out with water a few times in between scrubbing. This will rid them of any gunk attempting to clog the drain back up.

Step Five: Rinse and Replace The P-Trap

Use boiling water to rinse the trap out once more, and then replace it. You will do so by holding the P-trap in place. Then use the channel locks to replace the slip-joint nuts.

How To Prevent A Sour Smell In Bathroom

If you want to prevent a sour smell in your bathroom, you need to ward off future bacteria build-up. To keep bacteria at bay, regularly clean your bathroom drains. You can buy cleaner from most retail stores or just use the vinegar and baking soda mixture mentioned above.

If you followed the steps, and the smell is still present, it may be time to call a plumber. There is no shame in needing help from a professional.

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Related Questions

What is the black gunk build-up on your sink stopper?

Black gunk on your sink stopper is a heavy bacteria build-up. You will want to take the proper steps in cleaning your sink drain if you notice this.

Leaving something like this unattended can be a serious health risk to you and your family. Bacteria that are left sitting can grow mold, which carries diseases that can be harmful and even deadly.

What other smells should you be wary of in the bathroom?

A musty smell could indicate mildew or mold is developing in your bathroom. You already know mold can be harmful, so it may be ideal to go ahead and call a professional.

A dead animal smell could mean your P-trap has dried out. A sink that goes unused will not be able to keep the P-trap moist. This will lead to it drying out and allowing gasses into your home.

There are many smells to indicate potential problems. The smell of sewage could mean that your bathroom has a sewer pipe backed up. A primary chemical in sewage is methane, which can be very harmful to your family.

What are the best pipes to use for plumbing?

Copper pipes have a long history of being useful for plumbing. Companies have been using copper pipes for about 80 years. Not only are they less likely to pollute your drinking water, but they are also recyclable.

Stacy Randall
Stacy Randall

Stacy Randall is a wife, mother, and freelance writer from NOLA that has always had a love for DIY projects, home organization, and making spaces beautiful. Together with her husband, she has been spending the last several years lovingly renovating her grandparent's former home, making it their own and learning a lot about life along the way.

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