5 of the Most Common Reasons Why a Toilet Backup Occurs

Plumbing is necessary for any home because it brings water to the right places, such as the kitchen sink or the toilet. However, it’s arguably more important for the toilet because water is extensively used in the bathroom. Because of this, one should never take plumbing for granted.

People easily disregard toilet plumbing until something happens to it, such as a backup. A toilet backup is a highly unpleasant wastewater clog that requires the services of a professional plumber to resolve. You should never attempt to fix a clog on your own, as it’s a dangerous job that can lead to injury or damage to your home. However, it’s a homeowner’s responsibility to know the possible causes of a toilet backup, so we’ll discuss them in this article. These include:

#1 – The Tank Doesn’t Have Enough Water

One of the most common causes of a backup is that there isn’t enough water in the tank. You can easily remedy this problem by adding water to the tank. However, the tank may not be the only source of the problem because there can be many reasons the tank won’t fill up. The tank could be cracked or broken, so it won’t be able to keep any water in it. You should check the tank for any cracks or damage, and if you find any, you should call a plumber to have it replaced or repaired.

#2 – Something Stuck in the Trap

You should always be wary of what you flush down because some items can quickly get stuck in the trap and cause a backup. For example, a stray tampon or lots of toilet paper could get stuck in the trap and clog it. You should check the trap to ensure it’s free from any items that aren’t supposed to be there. If it is, you should remove the object.

This is a bigger problem if you have kids because they might flush their toys down the toilet. You should make sure you know what they’re flushing and make sure they know that they shouldn’t flush toys.

#3 – Main Sewer Line Clog

The main sewer line is responsible for bringing wastewater from the home to the city or county sewer system. If the main line becomes clogged, the wastewater won’t be able to leave your pipes, but it will continue to back up in the toilet. You should first check the main line to see if it’s clogged, and if it is, you should call a plumber to have it resolved.

Additionally, the main sewer line is also susceptible to clogs if it’s old, so you need to make sure it’s regularly maintained and inspected by a plumber.

#4 – A Clogged Drain Pipe

The drain pipe is what pipes the water away from your toilet, so it’s crucial to check it before you start to suspect a backup. The drain pipe could be clogged with hair or debris stopping the water from leaving the toilet.

If you see any gunk in the pipe, you should remove it. This can easily be done by using a large, sturdy pipe cleaner. You should also make sure the pipe is clean from any mold or gunk, so you may need to apply some bleach or vinegar to it. There’s also a chance you may need to replace the drain pipe if it’s old and liable to clogs.

#5 – Plumbing Vent Blockage

The plumbing vent is responsible for bringing fresh air into the bathroom and removing moisture. If the vent is blocked, it won’t be able to do either, resulting in a backup that occurs each time you flush the toilet. The vent can quickly become clogged with dust and mold you can’t see. Other debris such as hair and other trash can also block the vent.

If you suspect your vent is clogged, you should open the exterior wall and inspect it. If it’s clogged, you should immediately call a plumber to have it resolved.


If you suspect a backup, you should never attempt to resolve it yourself. You could end up becoming injured or damaging your home. To avoid those outcomes, you should always call a professional plumber to help resolve the issue. You should never take your toilet for granted, so it’s best to let a professional handle the job.

If you’re looking for plumbers in Thousand Oaks, California, Candu Plumbing & Rooter can help you!! Plumbing issues can happen anytime, so our services are available 24/7 for fair prices. Simply go to our website to book an appointment!