Most Common Reasons Your Toilet Is Gurgling & How To Solve It

Your toilet is an essential part of your home. However, most of the time, you use it, flush it, and maybe clean it periodically. You probably don’t spend much time thinking about your sewer pipes, blockages, and other potential issues.

That is until you have an issue and you need to call a reputable emergency plumber fast!

However, while the plumber is the best solution, it can help to understand what is going on with your toilet and if there is anything you can do about it.

Understanding Toilet Design

Your toilet constantly has water in the base of it. This stays in place thanks to the clever design of the toilet, effectively creating an ‘S’ trap. When the water level in your toilet rises it goes above the exit pipe, allowing the wastewater to move out of the toilet. As soon as the water in the toilet sinks below the level of the exit pipe it stops flowing out and the small quantity is trapped at the base of your toilet.

There is a good reason for this. The trapped water doesn’t allow air through. This means that the methane created in your waste pipes, from your waste products, is trapped on the outer side of the pipe. It can’t come into your home.

Methane is flammable and dangerous to your health, it’s a good thing that the water in the toilet keeps it out of your home.

Why Your Toilet Gurgles

You may be wondering how this is related to a gurgling toilet. The air around us is pressurized thanks to the atmosphere, the same is true of the air in the sewer pipes. This ensures that air and water can move smoothly through the pipes, carrying the waste products away. In effect, the air in your sewer pipe doesn’t create resistance because the air in your toilet is at the same pressure.

However, if the air becomes unbalanced, it will move from the higher pressure to the lower pressure. When the pressure is higher in the sewer pipe it will try to move to the lower pressure area, in your home.

Naturally, the air can’t get through easily as there is water in the way. The pressure will build until the air manages to pass through the water, creating a gurgling sound in the process. It may even be accompanied by a methane smell.

Your toilet will gurgle at any time and may gurgle more when you pull the flush as this allows larger volumes of air to escape.

The Cause Of Increased Air Pressure

If your waste system is enclosed, there is no escape for the air/methane that builds up from the waste and it will have to force its way through the toilet or reach dangerous levels in your pipes. This can potentially cause a fire.

To avoid this, all waste systems have a ventilation pipe fitted. You will see these on the outside of the house, they usually go straight up and will clear the roofline. This ensures the methane gas is vented, preventing pressure build-up. The height ensures it isn’t coming into your home through an upstairs window or another gap.

Of course, all pipes can get blocked. When this happens the air can’t escape and starts to build up, before being released into your home as a gurgling sound.

The most common reason for your ventilation pipe to get blocked is a bird’s nest.

You should note that a clog can also form in the waste pipe which will prevent the waste from flowing away and allow the build-up of gas.

How To Resolve The Issue

The first thing you need to do is find the clog. This is actually surprisingly easy. All you need is a drain camera. You can slide this into your drains and the ventilation pipe and it will show you a picture of the inside of the pipe. This allows you to confirm the condition of your pipes and to locate any clogs.

If you think the clog is in the ventilation pipe you can also go to the top of the pipe and look down it, there should be an inspection hatch to facilitate this.

It is also possible to go outside and lift any inspection hatches. If they are filled with wastewater the clog is closer to the main sewer lines. Alternatively, if they are dry the clog is closer to the house.

Once you have found the clog you can insert drain rods. These attach to each other to make them long enough to reach the clog. The front one has a special head that can push through the clog, breaking it up and eliminating the pressure issue.

You can also introduce a high-powered hose to blast the clog out of place. Or, if it is near the top of the ventilation pipe you will be able to hook it out with your hands or a small spade/trowel.

Fixing The Issue

There is no harm in trying to plunge the toilet, this may be enough to dislodge a small clog, depending on where it is. But, if you are plunging seal off all other drains in the house, to make sure the air can’t escape somewhere else instead of pushing the clog apart.

If it was a simple bird’s nest then removing it will resolve the issue and you simply need to cover the opening to your vent pipe with fine mesh, preventing it from happening again. However, if the clog is in your waste pipe and is due to a damaged pipe, you’re going to need to replace it.

This can be difficult, costly, and time-consuming. Replacing a sewer pipe means digging up the ground to access it and remove the damaged part. When replacing it check what caused the damage. Tree roots are a common culprit.

If it is a tree root you are going to need to trim them to prevent it from happening again. Or, you can always move the sewer pipe!