Why is there a sewer smell coming from my shower?

A sewer smell coming from your shower can be alarming and unpleasant. However, in most cases, it signifies an underlying issue that needs to be addressed. Identifying the root cause is key to eliminating the odor and preventing more severe problems down the line.

Most Common Causes of Sewer Smell in Shower

There are a few common culprits for a sewer odor in the shower:

  • Dried out P-trap
  • Cracked sewer vent pipe
  • Clogged shower drain
  • Malfunctioning wax ring under toilet

Let’s explore each of these common causes in more detail.

Dried Out P-Trap

P-traps are the u-shaped pipes underneath sinks and showers. They are designed to hold water, which creates a seal preventing sewer gases from entering the home. However, if a p-trap runs dry from lack of use, the water seal is broken and gases can escape.

Showers that are used infrequently are prone to drying out. The fix is relatively simple – pour water down the drain periodically to maintain the water seal. Installing p-trap primers can also help by automatically feeding water into the trap.

Cracked Sewer Vent Pipe

Sewer vent pipes equalize air pressure in the plumbing system and allow gases to escape outside. But cracks or breaks in these pipes can cause sewer gases to leak into the home. Vent pipe issues tend to cause smelly odors throughout the home, but the shower is often one of the first places it’s noticed.

Inspect the sewer vent pipes on the roof and along exterior walls. Look for any cracks, damage, or detached joints. Vent pipes may also become clogged with debris or nests, also causing gases to release inside. Professional repair or replacement is needed for damaged vents.

Clogged Shower Drain

When hair, soap scum, and other debris clog the shower drain, water cannot flow freely. The backed up water starts to stagnate and often creates a very foul odor. The smell will be especially pronounced when the shower is in use and new water runs into the clogged drain.

Trying a plunger or drain snake can clear out simple clogs. But severe blockages may require taking apart the drain underneath and manually removing the debris. Once fully clear, odor should dissipate quickly.

Malfunctioning Wax Ring Under Toilet

The wax ring forms a seal between the toilet and the drain pipe on the floor. This prevents any gases or leaks at the connection point. If the wax ring shifts, cracks, or becomes dislodged, gases can escape into the bathroom.

Since toilets are located near showers, a wax ring issue can easily cause odors in the shower as well. The only solution is replacing the wax ring – this usually requires temporarily removing the toilet.

Less Common Causes

If none of the above causes apply, there are a few less common issues that could lead to sewer smell in the shower:

  • Nearby sewer main problems
  • Broken sewer line under slab
  • Failed vent stack
  • Nearby RV dumping station

City sewer mains can sometimes have issues that let gases escape. A broken line under the foundation can also vent gases upward into a bathroom. Failed vent stacks on the roof don’t allow proper airflow. And proximity to an RV dump station can bring smells in through windows.

These problems are all harder to identify and solve on your own. Plumbing professionals have the equipment and skills to inspect sewer lines and pipes throughout the home and building. This can help pinpoint any breaches and allow targeted repairs.

How to Prevent Sewer Smells in Shower

To help prevent sewer smells from returning to your shower, consider these tips:

  • Pour water down floor drains monthly
  • Clean shower drain regularly
  • Install p-trap and vent pipe screens
  • Use p-trap primers where possible
  • Monitor wax ring under toilet

With regular maintenance like flushing pipes, clearing drains, and monitoring connections, you can avoid many causes of sewer odor in showers. Contact a professional plumber as soon as any new smells arise so the source can be diagnosed and fixed.

When to Call a Professional

While some causes of sewer smell in the shower can be DIY fixes, it’s best to call a professional plumber if:

  • Odors persist after trap maintenance and drain cleaning
  • Odors are also present throughout the home
  • You find damage to vent pipes
  • The toilet’s wax ring needs replacing
  • Sewer line repairs are required

A trained plumber has the skills and experience to fully diagnose odor issues in your plumbing system. They can pinpoint the source and make all necessary repairs to restore comfortable use of your shower.

Removing Lingering Odors

Even after the cause is fixed, odors can sometimes linger for a while. Try these tips to help remove remaining smells from your shower:

  • Run vinegar water down the drain – the acid helps kill bacteria
  • Scrub with baking soda – its odor-absorbing properties help soak up smells
  • Place charcoal briquettes in drain catch – charcoal is highly absorbent
  • Burn candles near shower – certain scents like citrus can overpower odors
  • Place bowls of coffee grounds – the grounds help absorb odors
  • Ventilate with fans – air circulation dissipates lingering smells

With consistent cleaning and airing out, your shower should return to normal soon after the sewer smell source is addressed.

When to Worry About Health Risks

While foul odors themselves pose no health problems, the gases causing them can sometimes indicate issues that do present risks. Contact a professional immediately if the sewer smell is accompanied by:

  • Numerous plumbing backups
  • Flooding from fixtures or toilets
  • Visible sewage water in the shower
  • A distinct rotten egg smell – could signify hydrogen sulfide gas

Sewer gases like methane and hydrogen sulfide can be hazardous at high concentrations. If your shower odor is severe or you suspect dangerous gases, avoid using the shower and call for professional help right away.

Sewer Odors Checklist

Use this quick checklist to help diagnose and fix a sewer smell coming from your shower:

Check P-trap water level Refill if needed to restore water seal
Clear shower drain clogs Use a plunger, snake, or remove and clean drain
Inspect vent pipes Look for cracks or blockages needing repair
Check toilet wax ring Replace if damaged or leaking gases
Pour water in floor drains Maintain water seals to prevent gas escape
Clean shower regularly Prevent buildup of residue that causes blockages

Following this checklist helps identify any maintenance that’s needed to stop odors at the source. Contact a professional plumber if issues persist beyond basic DIY fixes.

The Bottom Line

A sewer smell coming from your shower can be nauseating. But in most cases, it simply signals an underlying maintenance issue that needs attention. With some diligent troubleshooting and drain cleaning, you can likely resolve basic problems.

However, if odors persist despite your best efforts, reach out to a professional. A licensed plumber has the expertise to diagnose and fix any plumbing issues that are causing foul shower odors. With proper repairs, your shower will be fresh smelling once again.

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