Toilet Burps Big Bubble When Flushed | Why & How to Fix

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Have you ever flushed your toilet and out of nowhere, it burps big bubbles as the water runs down? Toilet gurgling is not the most uncommon issue and it especially shows when you try to flush the thing. If your toilet burps a big bubble when flushed, maybe it’s time to check under the hood and fix the problem.

There are a lot of possible reasons why the toilet burps a big bubble when flushed. But whatever the reason is, it is recommended to solve this as soon as possible before a major setback. Yes, burping the toilet can eventually generate symptoms like sending water back into the bowl with bubbles, flushing itself, and even cause a toilet backup for that matter.

And believe me, you do not want a toilet overflow in the bathroom because that is the worst mess you probably have to deal with ever. What’s more, it’s costly and time-consuming to fix an overflowed bathroom. So it’s better we get down to fix the gurgling toilet before it screws up, right?



Don’t worry, because we have the solution for you. First, we’ll figure out why the toilet burps big bubbles when you flush it. Then we’ll move on to how to fix a burping toilet and take care of the bubbles.

Why Does Toilet Burp When Flushed

The primary reason why the toilet burps when flushed is some kind of blockage. It may be the toilet’s drain, sewer drain, vent pipes, or anywhere else. Let’s take a look at some of the possible causes.

Toilet Clogging

A toilet can get clogged with various things for various reasons. Often it’s right in front of your eyes and easy to clean, but most of the time, you can’t see the blockers. It can be shredded toilet papers, debris, non-flushable materials that are causing the toilet clogging on its way to flush. It eventually blocks the water to flow through the pipes and gives air up to create bubbles.

To avoid such an incident, try disposing only of flushable stuff down the toilet, such as the necessities. Also, remember to flush every time you use the toilet to get rid of possible toilet clogging.

Air in Sewer Lines

The reason behind your toilet gurgling and making that awkward sound could simply be trapped air in the sewer lines. The air can build up due to simple toilet clogging or naturally, but it is one of the main reasons for the toilet burping big bubbles when flushed. It fills up the toilet drain and goes into the lines, and gives up with bubbles when you flush.

Vent Stack Blocking

The vent stack or vent pipe can usually be located on the roof or the upper side of the house. Vent stacks basically take care of the air pressure in the lines and equalize it so that the water inside can flow freely with the waste. They also exhaust gas and sewer odor as well.



Since it’s open on the roof, the vent pipe is exposed to outdoor blockages like leaves, bird nests, tree branches, debris, or even deceased small animals. They can get clogged inside the vent stack and affect the air circulation inside. Eventually, it can make the toilet gurgle when you flush it.

How to Fix a Gurgling Toilet

Now that we know why your toilet burps a big bubble when flushed, it’s time to fix it. Here are some of the basic attempts you can take yourself that doesn’t involve getting professional help.

Use a Toilet Plunger

The first and most basic thing you can do to fix a burping toilet is plunging the toilet. Before you begin, seal off the drains nearby so that the air doesn’t escape through there. Check your sink, shower, tub, and seal those drains temporarily with duct tape.

Once you’re ready, take a plunger to your toilet and start applying. As you plunge, you’ll bring out anything that is clogging the toilet and making it gurgle when flushed. Unclogging a toilet is one of the basic things to do when you are having trouble with flushing, toilet overflow, or more. If there is tissue, debris, chunks of hair that are clogging the toilet, the plunger will take them out and fix your toilet burping issue. After you’re done, take off the tapes from other drains and flush the toilet.

Snake the Drain Pipe

One other thing you can do to fix a gurgling toilet is using a sewer snake. Also knows as a toilet auger, a sewer snake is a long, flexible auger usually with blades on its head. It can be both manual or mechanical, but a sewer snake is excellent at cutting through tough clogs deep inside the toilet drain.

You can simply reach 10 to 15 feet with a snake to clear out blockages where plungers can’t reach. If necessary, use the blades to cut through clogs and clear the path, then flush the toilet. If it was a clogging issue, it should be solved and the toilet will not burp bubbles again.

Check the Vent Stack

While you are looking for the solution underground and can’t find any, it may have been above your head. We’ve already explained why your vent stack can get blocked and cause the toilet to gurgle with big bubbles. It’s time you check the place and clear any possible buildup.



If your vent pipe is on the roof, get up there carefully, possibly with an extension ladder. Open your vent pipe cover and examine the place for fallen leaves, debris, or anything. Visible blockages can simply be taken out with a wire and a hook, but be careful all the time. If you are not confident, do consider calling a professional in this case.

Call Your Neighbors

Calling the neighbors may not sound like a real solution, but bear with me. If your neighbors are having similar problems where their toilets also burp when flushed, maybe it’s the main sewer line. Fixing the sewer main is a job for the city corporation or the city’s sewer authority. Inform them about the issue you and your neighbors are having, let them inspect and solve the problem.

Frequently Asked Questions (FAQ)

Why does my toilet bubble up when I flush?

If your toilet bubbles up when flushed, it’s because your toilet line or the vent pipe is clogged with some kind of blockage, or there’s air in the lines.

How do you fix a gurgling toilet?

Use a plunger to plunge the toilet and remove possible blockages. If it doesn’t work, use a sewer snake to clear the deep toilet lines. You can call for professional help if none are successful.

How do I get rid of an airlock in my toilet?

Seal off nearby drains and apply a plunger in your toilet to get rid of an airlock inside.

How do you unclog a sewer line?

Remove the drain cap and run down an auger to unclog a sewer line. Go through tough blockages and then hose down with water to clear the line.

How do you unclog a vent pipe?

Check the vent pipe for possible materials that can clog like leaves, debris, dead animals, and take them off with a hook. Alternatively, you can use a plumber’s snake to run down the pipe and take care of the blocking.

Wrapping Up

There are common causes why the toilet burps a big bubble when flushed, but it’s nothing to worry about if you act quickly. It’s important to resolve this issue as soon as possible to avoid a future mess. Follow our DIY guides to fix a burping toilet and if necessary, call a professional.

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