Having a foul odor coming from your shower drain can be unpleasant and concerning. A common cause of a rotten egg smell in the shower drain is a buildup of bacteria, mold, mildew, and debris. This bacteria feeds on the hair, soap scum, and organic matter that collects in the drain. As it breaks down this waste, hydrogen sulfide gas is released, which produces that distinct rotten egg odor.
Here are some of the most common reasons why your shower drain may smell like rotten eggs and tips for eliminating the odor.
Causes of a Rotten Egg Smell from the Shower Drain
Buildup of Organic Matter
The number one cause of a sewer gas smell in the shower drain is a buildup of organic matter like hair, soap scum, and skin cells. This creates a moist environment where bacteria can thrive. As the bacteria ingest the organic waste, hydrogen sulfide gas is released during the breakdown process. This is what causes the rotten egg smell.
Regularly removing this buildup by cleaning the shower drain can help prevent smelly bacterial growth. Using a drain cover or drain strainer can also help catch hair and debris before it goes down the drain.
Clogged or Slow-Moving Drain
When the shower drain becomes clogged or drainage is slow, water can back up in the pipe. This stagnant water creates the perfect breeding ground for the sulfur-reducing bacteria that cause the rotten egg odor.
A slow drain may be caused by a partial clog from accumulated hair and soap scum. Tree roots or other blockages in the main sewer line can also impede drainage. Using chemical drain cleaners or a plumber’s snake to clear clogs can help get rid of smelly standing water.
Sewer Vent Pipe Issues
The sewer vent pipe attached to your home’s plumbing system helps relieve pressure and odors. When the vent pipe is obstructed, blocked, or improperly installed, sewer gas can back up through the shower drain. Issues with the vent pipe or plumbing ventilation system should be addressed by a qualified plumber.
Cracks in Sewer Pipes
Cracks, leaks, or damage in the sewer drainage pipes under or around your home can allow sewer gases to infiltrate the plumbing system and come up through the shower drain. If rotten egg odors only occur with a running shower, this may indicate a cracked drain pipe. A plumbing inspection can identify any leaks or damage.
Blocked Main Sewer Line
A significant clog or blockage deeper in the main sewer line or at the street connection can force sewer gas backwards through the pipes. This allows the smell to come up through drains. If you have a sewer gas smell from multiple drains in your home, there may be a larger issue in the main line. Professional drain cleaning or hydrojetting services can clear the deeper clog.
Improperly Installed P-Trap
The P-trap under sinks and showers keeps sewer gases from entering the home. When a P-trap is improperly installed, missing, or dried out, it loses this sealing capability allowing odors to leak out. A plumber can inspect for any issues with the P-trap setup.
Faulty Wax Ring
The wax ring beneath the toilet base forms a seal between the toilet and drainage pipe. If this wax ring is damaged, shifted, or incorrectly installed, sewer gas can escape around the toilet base and be noticeable around the shower drain. Replacing an old or faulty wax ring is a simple fix.
How to Get Rid of a Rotten Egg Smell from the Shower Drain
Getting rid of unpleasant sewer gas odors coming from the shower drain involves identifying and addressing the underlying cause. Here are some steps you can take to eliminate the rotten egg smell and prevent it from returning.
Remove Drain Clogs and Debris
Use a drain snake or zip-it tool to remove any hair or debris clogging the shower drain. Follow up by pouring boiling water down the drain to flush away bacteria and oils. You can also use an enzyme cleaner or bacteria treatment monthly to break down organic matter.
Disinfect and Deodorize the Drain
Cleaning products like bleach, hydrogen peroxide, and baking soda can all help disinfect and deodorize the drain. Try pouring a 1/2 cup of bleach or hydrogen peroxide down the drain, let it sit for 15 minutes, then rinse with hot water. Alternatively, dump 1/2 cup of baking soda down the drain followed by 1 cup of vinegar – the chemical reaction will bubble away grime.
Install a Drain Cover
A drain cover or strainer can prevent hair and debris from accumulating in the pipe and creating stinky clogs. Make sure to clean any debris from the drain strainer regularly.
Clean the Drain Vent Pipe
If there are issues with the drain vent pipe, have a plumber inspect and clean out any clogs. Proper venting will allow sewer gases to escape outdoors rather than indoors.
Identify and Repair Damaged Pipes
Inspect plumbing pipes for any cracks or damage that could let sewer gas leak in. A plumber can identify any faulty pipes and recommend repairs.
Treat the Sewer Line
For recurring rotten egg odors, you may need to have the main sewer line treated and sanitized. Products like septic tank treatments can help eliminate bacteria and improve drainage flow.
Install a Backflow Valve
A backflow valve installed on the main sewer line can prevent sewer gas from backing up into the plumbing drains. A professional plumber can determine if a backflow valve is needed.
Preventing Future Shower Drain Smells
To help prevent smelly odors from returning to your shower drain, here are some proactive maintenance steps:
- Use a drain strainer and clean it regularly
- Pour boiling water down the drain weekly
- Use a biodegradable drain cleaner monthly
- Avoid letting hair, soap scum, oils, and debris go down the drain
- Check for any leaky plumbing pipes and fixtures
- Make sure bathroom ventilation is working properly
- Keep the P-trap full of water
- Clean the sewer vent pipe annually
- Consider replumbing old or damaged pipes if needed
Addressing a rotten egg smell promptly and practicing good drain care makes it less likely to have a recurring problem. But if unpleasant odors return or persist, don’t hesitate to call a professional plumber to inspect the pipes and provide service to get your shower drain smelling fresh again.
Frequently Asked Questions About Shower Drains Smelling Like Rotten Eggs
Why does my shower drain smell like rotten eggs even after cleaning it thoroughly?
If you clean the drain and the smell comes back after a few days or weeks, there is likely an underlying issue allowing sewer gas to leak into the pipes, such as a clogged vent pipe, damaged pipes, or non-functioning P-trap. A plumber can inspect the plumbing and diagnose the source of the persisting rotten egg odor.
What should I do if boiling water and drain cleaner don’t help the smell?
If you have thoroughly cleaned and disinfected the drain but the rotten egg odor persists, there is likely a bigger problem requiring professional attention. Clogs deep in the main line, issues with the vent pipe or sewer gas leaks need to be addressed at their source by a plumber.
Is it normal for my shower to briefly smell like rotten eggs when I first turn it on?
It is normal to briefly get a whiff of the rotten egg odor when you first start running the shower, especially in the morning. This is caused by the water initially displacing sewer gases from the drain traps. Try running the bathroom vent fan to dispel the gases. If the smell lingers, there may be an issue allowing excess sewer gas into the bathroom.
Could a rotten egg smell while showering be a sign of a dangerous sewer gas leak?
It is unlikely the smell alone poses any immediate danger. However, hydrogen sulfide gas from sewers can potentially be hazardous at very high concentrations. If you suspect a dangerous leak in the plumbing, take precautions and have a plumber inspect for any cracked pipes, missing vent caps, or malfunctioning gas seals that could allow dangerous gas levels to accumulate.
What precautions should I take if the rotten egg smell from the shower drain is very strong?
A strong sewer gas smell indicates there may be a substantial amount of hydrogen sulfide gas leaking from the plumbing. Open windows for ventilation, avoid running the water to limit further discharge from the drain, and leave the home. Call a plumber immediately to fully diagnose and repair the issue before using the shower again. Serious plumbing leaks require immediate professional attention.
Conclusion
A rotten egg smell coming from the shower drain can be unpleasant and troublesome. In most cases, regular cleaning and maintenance can eliminate sewer odors. But a lingering rotten egg odor usually signals issues like drainage clogs, vent pipe blockages, broken pipes, or faulty plumbing that needs to be addressed. Identifying and resolving the underlying cause of the smell is the best way to keep your shower drain fresh smelling and free of foul odors.