Why is My Toilet Gurgling on a Septic System? (Explanation)

Written by

Paulk Webb


Freddie J. Hagopian

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why is my toilet gurgling on a septic system

People generally use our senses to detect signs of a problem that’s about to occur. Anything that’s unusual, especially within our homes automatically alerts us that something’s wrong.

As homeowners, we know that complications usually arise in the toilet. However, it’s easy to distinguish if the system has issues.

So, why is my toilet gurgling on a septic system? Different reasons might be associated with this. To sum it up, something’s delaying the air and water movement in the system.

Most Common Reasons Why is My Toilet Gurgling

1. Clog in toilet or drain pipes/main sewer line


A normal flowing toilet does not make any unnecessary noise. If you have a gurgling toilet septic tank, this could indicate that a clog is present either in your toilet, in the drain pipes or mainline.

A septic tank toilet bubbling is also an indicative of this issue. This happens when non-biodegradable items such as oils, greases, sanitary pads, and wet wipes are directly disposed into the toilet.

  • To address such problems, use a plunger push into the drain line. For larger blockages in deeper areas, toilet snake tools or plumbing auger can be used to unclog a septic tank drain pipe.

2. Blockage in vent pipe


The vent pipe is responsible for regulating the air pressure of a septic system. This is where the gas can exit too.

But just like the drain pipes, vents can also become clogged or damaged. If there is an obstruction or if it is broken, the air will find any alternative way out such as your toilet, creating a gurgling sound.

  • You should hire a plumber for this problem because the blockage could be deep in the vent. However, if the debris is right at the opening, which is commonly located on the house roof, you can examine and fix it yourself.

3. Low water level


If you hear a toilet gurgling, low water level might likely be the culprit. Monitor your toilet cistern and bowl’s water level. Insufficient water means lack of pressure, this could increase the chances to have a clog.

4. Septic tank is full


A full septic tank causes gurgling sound also. This is because the solid wastes and grease will prevent the flow of water from the tank to the drain field.

Aside from the toilet, your clothes washer could also affect the septic system. When the washing machine drains, the septic tank has the tendency to function improperly as there is a significant amount of wastewater released from your washer.

Once you have an overly full tank, the water cannot flow properly. That being said, the wastewater has nowhere to go so eventually it will end up backing to your home through the drains and toilet.

5. Floodwater fills drain field


After heavy rain, the septic tank might be filled with water. The system could no longer work properly as the drain field is already soaked with rainwater flood.

With this, the septic waste would start to back up. This could be another reason why your toilet creates a disturbing sound.

Frequently Asked Questions


How do you fix a gurgling toilet on a septic tank?

The easiest way to fix a gurgling septic tank is to make sure that your septic system and the toilet itself are operating properly, letting the water and air to move freely.

This could be done by eliminating any obstructions from all areas where problems might occur such as the drain pipes and vents.

What are the signs that your septic tank is full?

A septic tank making noise, an unpleasant smell, and trouble flushing are the top warning signs of a full septic tank.

Frequent back ups into your house, pooling water around the area where the system is located causing an overly green yard can also be symptoms of a full septic tank.

Furthermore, if you find it hard to flush your toilet or the toilet makes a weird gurgling sound, it’s time to emty the septic tank as it might be full.

How do I know if my septic line is clogged?

If you’re hearing a septic tank toilet gurgling, taking this for granted won’t be a good idea. This might be a sign that your septic line is clogged.

Other evident signs include the following:

  • Water backing up in your toilet
  • Slow drains
  • Sudden increase or decrease of toilet’s water level
  • Foul smell

What does it mean when your toilet bubbles septic tank?

When toilet bubbles, much like gurgling drains, the septic system might be having trouble. This could be an indication of a full tank or blocked vent pipes.

Also, if your toilet bubbles when the shower runs, the septic line might be clogged. Obstacles can block water or air from freely flowing; with this, the air would find the nearest drain-like your toilet- to escape.


Ever heard of a gurgling toilet? As if it’s telling you something you cannot understand and you just stand there wondering. So to answer the question, why is my toilet gurgling on a septic system– something is preventing the air and water from flowing normally.

Just like everything else, our toilet and septic system also need to be taken care of. But no matter how careful we are, situations may come offhand. Let’s face it, it could be such a dreadful experience but knowing the possible reasons behind it would be an advantage.

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