In this article, we will talk about the overflowing toilet and what to do if you encounter one.

An Anecdote

I want to share the story of Jennifer.  Jennifer and John were dating for a few months.  One night, John decided to surprise Jennifer and when he came to her apartment, he came with groceries.  John had decided that instead of going out to dinner, he would surprise her with his culinary skills.

Unfortunately for Jennifer, she never told John that she was lactose intolerant.  Instead of ruining the romance, she kept her mouth quiet and ate the dinner which has more than its fair share of butter and cheese.  Despite Jennifer’s best efforts, she had to break the romance to use the toilet.  If that was not bad enough, to Jennifer’s horror, when she flushed the toilet, she heard the telltale signs of her toilet overflowing.

How Do Toilets Work?

To understand why toilets overflow, you need to understand the making of the toilet.  Toilets have four main components:

  • A bowl
  • A reservoir tank with a flapper and a float
  • Water jets
  • U-pipe or trap.

When a person pushes the handle or presses a button, the flapper in the reservoir tanks lifts.  This sends the water in the reservoir down into the bowl by taking advantage of gravity.  This, along with water coming through the water jets, forces the existing water and waste in the bowl to discharge into the U-pipe which allows the waste to be discharged.  At the same time, as the float falls in the reservoir tank, more water enters until the float is at a height where the water will shut off until the next time the toilet is used.

All the components work together to allow for thousands of flushes without any incidence.  However, when one of the components fails to work properly, then it will cause the toilet as a hole to have problems.

What Causes Toilets To Overflow?

Five common causes that lead to toilets overflowing:


Obstructions happen when there is too much waste, such as a massive amount of toilet paper, or something that isn’t supposed to be flushed, such as baby wipes, q-tips, or plastic or metal objects, that are too big to be drained.

Excess water

If the float fails and more water than is needed is in the reservoir, then this might lead to an overflow.

Clogs in the U-pipe

If waste or debris somehow make it through the toilet, they sometimes become stuck in the pipes. This eventually leads to a buildup which will eventually cause an overflow.

Blocked vent

In order to prevent sewage from backing into your home, the u-pipe has water in it. When a toilet is flushed, water and air enter the u-pipe.  The air is released via an air vent through the rook.  If the air vent is blocked, then this can cause an overflow.

Full septic tank

If your toilet is connected to a septic system, then an overflow will occur is the septic tank is full and has not been emptied.

What To Do In An Overflow Situation?

The first thing to do when faced with an overflowing toilet is to stop the water from entering the bowl.  There are two ways this can be done.

  1. The first way is to hold the flapper down in the reservoir tank so no more water will enter the bowl.
  2. The second way is to shut off the water leading to the reservoir by turning off the water. Most toilets are built with a shut-off valve near the floor behind the toilet.

Once the water has been stopped from filling the bowl, the next step is to grab a plunger that is specifically made for a toilet.  By pumping the hole at the bottom of the toilet with a plunger, you are creating extra pressure that should help discharge the clog or blockage.  If you have a pipe snake, you can try using that to dislodge the blockage.  If after you plunge or use the snake and you are still having a problem, then give us a call and our trained licensed technicians will come to fix the problem.