Few things are more unpleasant than getting a whiff of a rotten egg smell coming from your bathroom drain. That stench seems to permeate the air and make your bathroom nearly unusable. While it may temporarily disappear after running the water, that rotten egg odor inevitably returns with a vengeance.
If you’re dealing with this nasty issue, you’re probably eager to learn what causes that embarrassing rotten egg smell and how to get rid of it quickly.
What Causes a Rotten Egg Smell from Your Bathroom Drain?
Before you can stop that awful sewer stench, it helps to understand what causes a drain to smell like rotten eggs in the first place. Here are the most common culprits behind a smelly bathroom drain:
Hydrogen Sulfide Gas Produced by Sewer Bacteria
The primary cause of a rotten egg smell is hydrogen sulfide gas. This gas is produced by bacteria that naturally live and thrive in the warm, moist environment inside your drain pipes and sewer line.
As these bacteria feed on debris, fats, soaps, and other substances going down your drain, hydrogen sulfide is released as a byproduct. The gas travels up your pipes and releases its telltale rotten egg odor when you turn on the tap or flush the toilet.
Clogged or Partially Clogged Drains
When drains become clogged with grease, hair, and other gunk, it slows down the water flow. This allows bacteria and hydrogen sulfide gas to accumulate in the backed-up water.
As water passes by these clogged areas, it carries that rotten egg gas up through the drain, releasing the odor into your bathroom. Even a partial clog that doesn’t completely block water flow can still trap enough bacteria and gas to cause a smell.
Dry P-Traps
The p-trap under your sink is a U-shaped piece of pipe designed to hold water to prevent sewer gas from entering your home. However, when sinks and showers aren’t used frequently, the water in the p-trap can evaporate over time.
This allows sewer gases, like hydrogen sulfide, to travel up through the dry drain and escape into the air. Pouring water down unused drains on a regular basis can help maintain the water seal and block unpleasant sewer odors.
3 Common Causes of Clogged or Slow Bathroom Drains
While smelly drains are often caused by clogged or partially clogged pipes, what exactly leads to those clogged drains in the first place? Here are three of the most common culprits behind bathroom drain clogs:
Accumulated Hair and Grime in Pipes
It’s easy for hair and shampoo residue to wash down the drain while showering. Over time, these strands accumulate and mat together with soap scum and body oils to form a thick, sticky mass along pipe walls.
This accumulation gradually narrows the drain openings, slowing water flow and allowing for gas and bacteria buildup. Hair catchers can help collect strands before they go down the drain.
Grease and Food Scraps Down the Drain
Grease, fats, and food scraps washed down the kitchen sink eventually harden and stick to the insides of drain pipes. These greasy deposits narrow pipe openings and provide food for bacteria.
Rotting food particles get trapped, allowing hydrogen sulfide gas production. Avoid pouring fats and oils down drains – wipe them up with paper towels instead.
Tree Roots Invading Pipes
Tree and plant roots can invade drain lines while searching for water. Over time, this invading root system grows to clog pipes and cause water backup.
Low water flow and blockages encourage bacterial growth and hydrogen sulfide gas accumulation. Tree roots strangling drain lines often require professional removal.
3 Ways to Get Rid of a Rotten Egg Smell from Your Drain
Now that you know what’s causing the stench, it’s time to learn how to get rid of that offensive rotten egg odor coming from your bathroom drain. Here are three effective solutions you can try:
Pour Baking Soda and Vinegar Down the Drain
For a simple DIY treatment, try pouring 1 cup baking soda down the drain, followed by 1 cup vinegar. Let the fizzing and bubbling mixture sit for 5-10 minutes to work on breaking up gunk.
The baking soda helps absorb nasty odors, while the vinegar works to dissolve soap scum, hair, and other grime. After letting it sit, rinse with hot water to flush away the cleaner.
Use a Drain Snake to Remove Clogs
A drain snake, also called an auger, uses a long flexible cable you manually feed down your pipes while twisting to catch debris. It works great for pulling out wads of hair and dislodging globs of grease clogging your drain.
Regularly using a drain snake helps remove built-up gunk and keeps water flowing quickly, preventing future bacteria and gas buildup.
Have a Professional Clean Your Drains
For extensive drain cleaning, call a professional plumber. They have high pressure water jet tools that can thoroughly scour the insides of your pipes.
A professional can also snake the drain with a specialized auger to reach clogs deeper in your pipes. They may also use a camera to inspect your pipes and diagnose issues out of DIY reach.
When to Call a Professional Plumber About a Smelly Drain
While simple drain cleaning techniques may cure an occasional rotten egg smell, it’s best to call a plumber if:
- DIY treatments don’t eliminate the rotten egg odor
- The smell seems to come from multiple drains
- The odor is very strong or happens even with little drain use
- You have other plumbing issues like leaks or black water
- A home inspection reveals venting issues, cracked pipes, etc.
A persistent rotten egg smell often indicates a bigger problem that requires professional equipment and expertise to fix. Don’t hesitate to call a plumber for severe or persistent sewer gas odors.
How to Prevent Smelly Drains in the Future
To help avoid dealing with smelly drains again, take these preventive measures:
Pour Water Down Unused Drains Weekly
Letting taps and showers run for a minute or two weekly flushes your pipes and replenishes the p-trap water seal. This blocks sewer gases from entering through unused drains when the water evaporates.
Avoid Pouring Fats/Oils Down the Drain
Greasy, fatty foods washed down the drain will eventually cool and harden into clogs. Always wipe away cooking oils, meats, and buttery sauces with paper towels instead of rinsing them.
Install Hair Catchers
Place hair catchers or drain screens over shower and sink drains to collect strands before they can go down the pipe. Clean out hair from these devices regularly.
Use Enzyme Cleaners Monthly
Monthly application of an enzyme cleaner or foaming drain maintainer helps break down organic buildup that clogs pipes and feeds bacteria growth.
Preventative annual drain cleaning removes any accumulation and keeps your pipes clear. This helps avoid major future clogs and sewer gas backups.
Dealing with a rotten egg smell coming from your bathroom drain can be unpleasant and embarrassing. But armed with the right knowledge, you can tackle this common issue. Follow these tips to banish drain odors and keep your bathroom fresh.
