You walk into your bathroom expecting that familiar clean scent — but instead, a foul sewer smell in your bathroom hits you. It’s sharp, unpleasant, and makes you wonder what’s gone wrong behind the walls or beneath the drain. A bathroom that smells like sewage could signal a serious plumbing issue that needs immediate attention.
It doesn’t happen by accident that your bathroom smells like sewer gas. Whether it’s a clogged shower drain, a leaky wax ring, or a broken sewer line, it’s frequently a warning sign from your plumbing system that something is letting sewage gases into your house. Early detection of these issues can help you avoid future expensive repairs.
In this blog, we’ll break down the most common causes of sewer smells in bathrooms, how to diagnose where the smell is coming from, and practical DIY solutions like baking soda and vinegar that might help. We’ll also explain when it’s time to call a professional Toronto plumber like Absolute Draining & Plumbing, your trusted experts for sewer camera inspections, sewer repairs, and drain cleaning services across the GTA.
Get in touch with Absolute Draining & Plumbing for expert bathroom odour solutions in Toronto, Etobicoke, Mississauga, and across the GTA.
Bathroom Smells Like Sewer? A Clogged Shower Drain May Be Causing the Sewage Odour
A clogged shower drain is one of the most frequent causes of the sewage-like odour in your bathroom. Soap scum, hair, and oils build up in your bathroom sink and shower drain over time, causing a blockage that holds organic matter and moisture. Sewer gas-like odours are produced by the bacteria that grow inside these moist blockages.
DIY Solutions for a Clogged Shower Drain
Before calling a plumber, try these DIY solutions to remove the buildup and get rid of the sewer smell.
- Pour hot water down the drain. Sometimes, flushing your drain with boiling water can break down soap residue and grease, helping eliminate the odour in your bathroom.
- Use baking soda and vinegar. Pour one cup of baking soda, followed by one cup of vinegar and a cup of hot water. Cover the drain for 10–15 minutes, then rinse again with hot water. This natural reaction helps dissolve buildup and neutralizes sewage odours in your bathroom sewer.
- Try a drain snake. If the smell persists, insert a drain auger into the pipe to pull out hair and debris causing the blockage.
If you’ve tried these fixes and the bathroom smells like sewer remains, the problem may be deeper in the sewer line, requiring sewer camera inspections from a licensed plumber to locate and fix the problem.
The P-Trap Might Be Allowing Sewer Gases to Escape
Another common cause of sewer odours is a dry or damaged P-trap. The U-shaped pipe under your sink, shower, or tub is designed to hold water, preventing sewer gases from entering your bathroom. When it dries out — usually in guest bathrooms or infrequently used areas — it stops acting as a seal, allowing sewer gases to escape into the air.
What Causes P-Trap Problems
- Infrequent use: If water evaporates, there’s nothing left to block the sewer gas smell.
- Cracks or leaks: A leaky pipe can allow sewer gases to escape and spread that rotten egg smell throughout your home.
- Improper installation: A poorly installed trap can let sewage gases leak into your bathroom.
Quick Fix
Run hot water for 30 seconds to refill the P-trap with water. This creates a barrier that helps prevent sewer gases from entering your bathroom again. If the smell of sewage returns or the pipe appears cracked, call a professional plumber in Toronto to replace or reseal it.
A Damaged Wax Ring Could Let Sewer Gases Leak Around the Toilet
If your bathroom smells like sewage and the odour is strongest near the toilet, the culprit may be a broken wax ring. This ring forms an airtight seal between the toilet base and the sewer pipe, preventing sewer gases from leaking into your home.
Signs of a Failing Wax Ring
- You see water collecting near the base of the toilet.
- Even after cleaning, the bathroom still has a sewage gas odour.
- When seated, the toilet wobbles a little.
Replacing a wax ring often requires you to remove the toilet, which can be tricky for homeowners. If done incorrectly, it can allow sewer gases to enter your bathroom or cause leaks. A licensed plumber can safely remove the toilet, install a new wax ring, and check for cracks in the sewer line below.
Sewer Backup or Broken Sewer Pipes Can Cause Persistent Sewage Odours
A broken sewer line or sewer backup is evident when actual bathroom sewage or sewer gas backs up into your bathroom. This major plumbing problem can let sewage and sewer gases into your house, giving it a foul odour that won’t go away with routine cleaning.
Common Causes of Sewer Backups
- Tree roots are breaking into underground sewer pipes.
- Aging clay pipes are cracking over time.
- Grease or debris buildup causes blockages in the sewer system.
- Heavy rainfall overloads city sewers, pushing wastewater back into your bathroom.
Professional Fixes for Sewer Problems
A qualified plumber can perform sewer camera inspections to locate the blockage or break. Using modern tools, they can recommend trenchless sewer repairs, which replace damaged sections of pipe without large-scale digging. This solution restores proper flow and helps get rid of the sewer smell in your home permanently.
A Blocked Vent Pipe Can Cause a Sewer Smell in the Bathroom
Your plumbing vent pipe helps balance air pressure in the sewer system and directs sewage gases outside. When this pipe gets blocked by debris, snow, or even a bird’s nest, sewer gases have nowhere to go — so they escape through your drains instead.
How to Tell If a Vent Pipe Is Blocked
- You hear gurgling sounds when flushing.
- Water drains slowly from sinks or showers.
- You notice a persistent sewage odour near the walls or ceiling.
Only a licensed Toronto plumber should inspect and repair vent pipes. They can use a smoke machine or sewer camera to pinpoint leaks, cracks, or obstructions, then fix the problem safely and effectively to restore proper ventilation and eliminate the sewer odour.
Contact Absolute Draining & Plumbing for reliable plumbing services throughout Toronto, Etobicoke, Mississauga, and the GTA — from clogged drains to broken sewer lines.
Bacteria Growth or a Full Septic Tank Can Cause Sewage Smells
If your house smells like a sewer, and you’re not on a municipal system, your septic tank may be full. When tanks reach capacity, sewage can back up through drains, spreading an awful smell. For homes connected to the city’s sewer, bacterial growth in your pipes can also cause sewage smells in bathrooms.
Fixes for These Issues
- Schedule septic tank pumping: Have your septic system pumped every 2–3 years to prevent sewage from backing up.
- Use drain-safe cleaners: Avoid harsh chemicals that can damage pipes, and instead use a natural solution like baking soda and vinegar to kill bacteria.
- Hire a plumber for hydro-jetting: Professional drain cleaning can get rid of odours coming from deep within your sewage systems and remove stubborn deposits.
Why Does My Bathroom Need to Prevent Sewer Gases and Keep Your Bathroom Smelling Clean
Preventing a bathroom smell like sewage is much easier than dealing with one. Here are simple steps to maintain a clean-smelling bathroom and avoid future sewage odours:
- Run Water Regularly. Turn on showers and faucets once a week if you have a guest bathroom to maintain water in the P-trap and keep sewage gases out of your house.
- Clean Your Drains Monthly. To remove residue, add vinegar and baking soda, then hot water. This not only helps get rid of sewer smells but also keeps your drain pipes clear.
- Inspect for Leaks. Sewer gases can escape through even a tiny leak beneath your sink or around your toilet. If you notice dampness or a rotten egg smell, it’s time to call a plumber.
- Schedule Regular Sewer Camera Inspections. Professional inspections help detect cracks or root intrusions in your sewer lines before they become major issues. Absolute Draining & Plumbing offers advanced sewer camera inspections across Toronto to ensure your sewer system is healthy.
- Check Vent Pipes and Traps. Make sure your vent pipe isn’t clogged and your P-traps hold water to prevent sewer gases from escaping.
- Avoid Flushing Non-Degradable Items. Paper towels, wipes, and feminine hygiene products can block sewer pipes, cause sewer backup, and spread sewage smell in the bathroom.
By following these measures, you can maintain a clean-smelling bathroom and keep sewage in your home’s plumbing system, where it belongs.
When to Call a Professional Plumber in Toronto
It’s time to hire an expert if you’ve attempted DIY methods but your bathroom still stinks like sewage. A chronic sewage smell frequently indicates an underlying plumbing problem that can only be properly diagnosed and fixed by an expert.
At Absolute Draining & Plumbing, our certified Toronto plumbers specialize in drain cleaning and sewer repairs, sewer camera inspections, backwater valve installations, trenchless sewer replacements, and 24/7 emergency plumbing.
We’ve helped countless homeowners get rid of sewer smells, repair broken sewer pipes, and restore safe, clean-smelling bathrooms.
Contact Absolute Draining & Plumbing, trusted by homeowners in Toronto, Etobicoke, Mississauga, and the GTA for safe, long-lasting plumbing and sewer repair solutions.
Keep Your Bathroom Clean and Odour-Free — Call Our Experts Today!
A bathroom that smells like sewage isn’t something to ignore. Whether it’s a clogged shower drain, wax ring leak, or broken sewer line, the team at Absolute Draining & Plumbing can help you fix the problem fast.
Prevent sewage backflow in your home by keeping sewer gases at bay. For professional sewer camera inspections, drain cleaning, and sewer repairs that are supported by flat-rate pricing, a 25-year drain repair warranty, and dependable service, get in touch with Absolute Draining & Plumbing right now.
