Why Does My Shower Drain Smell? Time To Call Plumbers | San Antonio, TX

Why Does My Shower Drain Smell? Time To Call Plumbers | San Antonio, TX

Photo By Jari Hindstroem at Shutterstock

Have your showers been ruined recently with a foul odor wafting in from the drain? There’s nothing worse than a relaxing shower or bath being ruined by an unpleasant smell. A stinky shower drain is a much more common problem than you may think. In fact, it’s one of the most common issues plumbers are called in for. In this guide, we break down what may be causing your smelly shower drain and steps on what to do next.

Clogged Strainer (or Stopper)

Most showers have a strainer or stopper to catch items from going down the drain. If your shower doesn’t have one, it’s more than likely you put a temporary one on top. These filters catch items such as hair, soap scum, and other debris from going down the pipes. However, the stopper itself can become plugged if it begins to accumulate enough build-up.

Solution: Some showers have easily removable strainers that pop out. If this is the case for yours, make sure to take it out and clean it every couple of months. Remove any debris, clean the strainer with a toothbrush, and look down the drain to make sure there’s no debris left to clean out from the pipes.

If you notice a blockage further down the drain, you will have to call a plumber for drain cleaning.

Not all shower strainers are easy to remove. If your stopper requires you to use tools to get it out, it’s probably best to call a professional instead.

Mildew or Mold Growth

Another possible explanation for the unpleasant odor is fungi growth. Mildew and mold love to grow in dark, wet places, and your shower drain provides the perfect breeding ground. Check your drain cover to see if it’s loose. If the drain cover isn’t completely sealed, the small, wet area is a breeding ground for fungi growth.


Solution: If you can, remove the shower drain cover and clean it thoroughly with a mold or mildew growth removal cleaner. Clean and spray the entire drain area (the underside and the ring) with the mildew growth removal solution as well. Next, place it back with an airtight seal. If your shower drain cover doesn’t have an airtight seal, it’s been damaged and needs to be replaced. You will need to call plumbers for this replacement job.

Dry or Dirty P-Trap

The “p-trap” in your shower is the curving portion of the pipe drain that connects the drain to the rest of the drain system. It gets its name of “p-trap” because it curves in a distinctive p shape. The curved p-shape allows the pipe to hold some of the water that drains through it. This captured water helps block sewer gases that would otherwise release up from the pipes into the house. A smell of rotten eggs is a sign that the p-trap in your shower isn’t working correctly.


Solution: Remove the shower strainer and shine a flashlight to see if there’s water in the drain. If you don’t see any water, you can test the mechanism. Pour two cups of water down the drain and wait an hour. After the time is up, if there’s no water in the pipe, it’s time to call plumbers to fix your dirty, blocked, or broken p-trap.

Biofilm Buildup

A common issue in showers is biofilm build-up. Biofilm looks like slime or muck and is usually found in the shower (walls, floors) and in the shower drains. In fact, biofilm is a substance that forms from a colony of bacteria and bacterial waste. If your shower smells musty, it could be a sign of biofilm growth.

Biofilm can be dangerous as it contributes to the spread of E.coli, S.marcescens, and salmonella. For that reason alone, biofilm is much more than just an odor issue and needs to be fixed right away.


Solution: If you notice biofilm on your shower walls, make sure to wash them with a strong cleaning product every week. A musty smell in the shower though, means the biofilm may be in the drain. If you can, remove your shower strainer and clean it thoroughly. If the smell doesn’t go away, it’s time to call plumbers for help. Remember, biofilm is a health hazard, so it’s not something to ignore.

Leaky Pipes

Unfortunately, leaky pipes can be the culprit of a bad smell in the shower. Leaky pipes allow sewer gases (hydrogen sulfide) to escape, making the shower smell like sewage or rotten eggs. A smell of sewage in your home is almost always a sign of a severe plumbing issue and should never be ignored.

Leaks are typically caused by cracks in the pipes of loose fittings between pipe connections. Some metal pipes will corrode over time, resulting in leaks.


Solution: Leaky pipes are not a DIY problem. Plumbers must be called to confirm a leaky pipe problem, access them, and resolve the issue. The possible solution will vary depending on the type of material your pipes are made of and how bad the leak is. Only licensed plumbers can safely locate the leak and fix it.

Clogged Vents

If water is disappearing from the p-trap, it could be because the shower vents are blocked. When air is introduced into the drain system via water, the pipe venting gives the air an exit point. If the air has nowhere to go, it creates a suction vacuum inside the pipes, which repeatedly siphons water out of the p-trap. Usually, the pipe venting connects to an outlet called a “vent stack.” The clogs often occur in the vent stacks. Debris may fall and block the vent stack, or a bird may build a nest in front of it.


Solution: If you know where your vent stack is located, you could take a look to make sure nothing is blocking it. However, if you don’t know the location, it’s best to call plumbers in to diagnose and resolve the issue.

BlueFrog Plumbing 

If you’re looking for plumbers in San Antonio, TX, bluefrog Plumbing + Drain is the right choice every time. We have been providing quality service to the San Antonio, TX community for many years. Our plumbers will diagnose that shower drain smell, fix it quickly, and give you tips to prevent it from recurring. Call us today to have the pleasant hot showers you deserve!

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