Here’s a nasty situation we hear from homeowners, “When I flush my toilet, the toilet water rises out of the shower drain.”
So their question is, “Why in the world would my toilet water back up into my shower drain?”
The cause: sewer line clog
Basically, your toilet is trying to use a sewer line to transport water waste from your home
to the underground sewer main.
But because you have a clog in the sewer line, raw sewage can’t exit the home and instead backs up through other drains (in this case, the shower drain).
Get a plumber to clear the sewer line clog ASAP. Why so quickly? A sewer line clog presents a health hazard to your family and will eventually lead to a pricy sewer line repair or replacement.
Main line vs. secondary line clogs
When a plumber comes by, they may mention that you have a clog in the “main sewer line” or a “secondary sewer line.”
What does that mean?
Well, your home’s plumbing is like a tree:
If the clog is in a secondary sewer line, then only a few drains will back up. In your case, the water from the toilet is backing up into the shower.
But if the clog is in the main line, you’ll have issues with every drain in your home, not just the toilet and shower drain.
“Can I fix it myself?”
Unfortunately, no. Clogs down in the sewer line (especially the main line) can’t be fixed by a simple plunger or toilet auger.
You’ll need to call a professional plumber to find the location of the clog and clear it.
Typically, a professional plumber will approach the problem like this:
Best case scenario: The auger fixes everything and you go about your day.
Worst case scenario: The sewer line camera finds a serious issue, like tree roots growing the sewer line. Or the sewer line has collapsed and needs replacing.