Why Is Water Backing Up in My Bathtub When I Flush My Toilet?

September 26, 2017

If you flushed your toilet then noticed a large pool of questionable water in your bathtub, you probably know something’s not quite right (and you’re probably grossed out).

So, what’s the likely culprit of this problem? A clogged sewer line.

Let’s take a closer look at how a clogged sewer line causes this common plumbing issue…

Need help right away? Give Red Cap Plumbing a call. We’ll unclog your sewer line and get your plumbing system back to normal.

How a clogged sewer line can cause toilet water to appear in your tub

All of your plumbing devices (toilets, sinks, bathtubs, etc.) feed into the same main sewer line.

If your drains and main sewer drain are clear of debris, water flows easily and effortlessly out of your home when you flush the toilet (as seen in the image below).

Drain Diagram Bathroom Clean

But, if you have a clog in the main sewer drain line, water gets directed to the next opening, in this case, your bathtub (see image below). 

Drain Diagram Bathroom Clogged 1

Since the main sewer line isn’t completely clogged, the water in your bathtub will eventually empty out within a few minutes and go back into the main sewer drain.

So how do sewer lines clog up in the first place?

What causes main sewer lines to clog

A few causes of sewer line clogs include…

  • Tree roots: As roots search for water they can force their way into an old sewer line. And as the roots grow, they clog up your plumbing system.  
  • Grease buildup: Even though grease goes down your drain as a liquid, once it cools and congeals it will form a solid mass that’ll clog up your main sewer line.
  • Feminine hygiene products: Flushing tampons down the toilet clogs the main sewer line (so don’t do it!).
  • Toys: Wondering where your kids’ toys are disappearing to? Unfortunately, they may be clogging up your sewer line. 

So these are some objects that may be clogging your sewer line, but how can you fix it?

How to fix a clogged sewer drain line

The bottom line? Call a professional plumber to clear the sewer drain line.

Here’s why you need a professional’s help: No amount of plunging will dislodge the sewer line (note in the images above how far away the main sewer line is from the other drain lines), so don’t attempt any plunging or plumbing repairs yourself.

A plumber will perform a video inspection to see where the clog is, then use tools like a closet auger to clear your clog.

tree roots taken from plumbing pipes with an auger

Tree roots taken from plumbing pipes with an auger

In the case of tree roots, a plumber will need to cut those out of the pipe and then replace the ruptured pipe.

Need a reliable plumber to clear your sewer line?

Contact Red Cap Plumbing to schedule an appointment with one of our skilled plumbers to unclog your sewer line. 

We’ll get your kid’s missing action figure out of there (or whatever’s causing the clog) and restore your home’s sewer pipes.

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