Toilet Bubbles When Flushing

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Are you seeing toilet bubbles and gurgles when you flush your toilet? Seeing a bubbling toilet can be quite annoying, leave alone frustrating.

A gurgling or bubbling sound is something like the plumbing system has a problem that requires your attention. Toilet bubbles and gurgles when flushed occur when there is a blockage somewhere in your sewer line. The good news is that you can easily fix toilet bubbles without necessarily calling in a professional. Usually the reason for when a toilet bubbles is a bad clog but you can easily learn how to unclog toilet when nothing works.

Here are some of the causes of toilet bubbles and how you can fix them:

A Clogged Toilet

Paper towels, toilet paper, feminine products, cigarette butts, and flushable wipes are just some of the things that can cause your toilet to become clogged. If not attended to, a clogged toilet will definitely result in gurgling and bubbling sounds when flushed. The best way to deal with a clogged toilet is by using a plunger. You can also use a plumbing snake or toilet auger to clear the blockage.

Make sure you seal off any other fixtures in your bathroom with duct tape before plunging into the toilet. This will keep pressure from escaping and allow it to clear the drain line. If the plunger doesn't do the job, use a manual or mechanized sewer snake or plumber's snake to clear out harder-to-reach and hard clogs.

Blockage in the Vent Stacks

If your home has more than one story, then you most likely have a vent stack. A vent stack is a vertical pipe leading to your roof that helps control your plumbing air pressure and releases exhaust gas. If this pipe becomes blocked, closed, or sealed, it can lead to reverse suction, causing bubbling and gurgling sounds when flushing the toilet on the lowest floor of your home.

When this vent pipe is blocked, it will cause negative pressure, leading to the same bubbling sounds. These plumbing vents can be blocked by animals building their nests there, debris, and leaves. A carcass of small animals, including bats and rodents, may also cause the blockage.

To fix this problem, climb your roof to establish where the blockage is. If it's noticeable and easy to reach, you can unblock it yourself. Grab a ladder and climb your roof, then use a garden hose to spray water down the vent stack tube.

If you don't have a sprayer gun for your garden hose, consider buying one before attempting this task, as it can save you time. If you're not comfortable fixing it yourself, then leave it to professional plumbers to take care of.

Clogged Municipal Sewer Line

If you live in a municipal sewer system area, your home is connected to this mainline. If this line becomes clogged or damaged, it will cause the water to back up and bubble out of your toilet bowl. A municipal sewer pipe is what everyone's mainline dumps into, taking all that wastewater to be treated.

If you think this is the issue, speak to your neighbors and see if they're experiencing the same problems as you do. If so, check your water provider and report the issue immediately. Make sure you work with your local sewer authority to get the issue repaired. This way, you won't have to come out of pocket for any costs.

Sediment Buildup

Over time, sediment and minerals can build up in your home's pipes. This is especially true if you have hard water. When this happens, it can restrict the flow of water and cause your toilet to bubble when flushed.

Sediment Buildup
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If you think sediment buildup is causing your problem, inspect and replace the water inlet lines inside your home if they appear discolored. They'll appear reddish-orange if they're discolored. You can also use a commercial cleaner to remove buildup from your pipes. If you have a septic tank, it's also essential to have it pumped every few years to prevent sediment from building up and causing problems.

Toilet on Septic Bubbles When Flushed

If you use a septic tank and notice that the toilet bubbles when you flush it, the problem may be with your septic tank. If the sludge and scum levels in your septic tank are too high, they can back up into your home's drains and cause your toilet to bubble when flushed.

Alternatively, the drainpipe to the septic might also be clogged. If your tank is full, you undoubtedly need to empty it, but a clogged drainpipe can be easily unclogged either by yourself or call a plumber to help you.

Drain Line Clog Creates Air Bubbles

If you do not have a septic tank, the problem is likely that your home's main drain line is clogged. This can cause air bubbles to form in the toilet when flushed because water cannot flow through the drain line as it should. The clogging can be from disinfecting wipes, paper towels, or other debris mixed with human waste that doesn't easily break down in the drain lines.

A partial clog in the drain line will allow air to be pushed backwards along the drain line because the water level will get temporarily raised in the drain pipes when you flush. In this case, a bubbling or gurgling toilet can be a useful sign that there is a problem with your drain or sewer line.

If your sewer lines get completely blocked, it can cause your toilets to back up, overflow, or even flood your bathroom with sewage. A blocked sewer line can also cause slow drains throughout your home. If you notice any of these problems, it's important to call a professional plumber right away to clear the blockage and prevent further damage.

How to Fix a Toilet That Bubbles

If your toilet bubbles when flushed, it's important to take action immediately, as ignoring the problem can lead to serious damage. Even if it means purchasing a new toilet, make sure you shop for the best flushing toilet on the market. The first step is to figure out what's causing the problem. In most cases, a bubbling toilet is caused by a blockage in the sewer line. This can be caused by anything from tree roots to grease buildup.

Unclog the Toilet Using a Toilet Plunger

When your toilet is clogged, the plunger is the quickest and easiest way to get things flowing again. For best results, use a toilet plunger with an extended flange that fits snugly over the drain opening.

Unclog the Toilet Using a Toilet Plunger
Image credit: Unclog the Toilet Using a Toilet Plunger

Make sure you get a good seal to effectively remove the clog from the toilet. This means placing the plunger directly over the drain hole and pressing it down firmly. To check if the problem is solved, flush the toilet again and see if it bubbles. If this doesn't work, move to a more thorough to ensure you unclog your toilet.

Unclog Your Toilet Using Toilet Auger

Unclog your toilet without a plunger by using a toilet auger or plumber's snake. A toilet auger is a long, flexible rod with a handle on one end and a coiled wire on the other that is used to clear blockages in toilets. Most toilet augers are between 3 to 6 feet, but most professional plumbers often use motorized augers which can exceed 100 feet.

Unclog Your Toilet Using Toilet Auger
Image credit: Unclog Your Toilet Using Toilet Auger

To use a toilet auger, insert the auger into the toilet bowl and position it, so the coil is over the drain hole. Push the auger handle to rotate the coil and work it through the blockage. When you feel resistance, continue pushing and rotating until you've broken through the clog. Slowly retract the auger and flush the toilet to clear any remaining debris.

Check and Unclog the Vent Stack

You never know how important a vent is until it gets clogged and sewer gases are backing up in your kitchen sink drain, a bathtub drain, or a toilet that bubbles when flushed. Your entire house will smell like a sewer.

When your toilet vent stack is clogged, sewer gases get stuck inside the vent stack, resulting in negative air pressure. When the pressure is more than the toilet bowl can take, the toilet bubbles.

To unclog a blocked vent stack, climb up to the top of the roof of your house with a garden using a ladder. Proceed and carefully remove the cap of the vent with a screwdriver. After that, use a small brush to clean out the dirt and debris that might have clogged the vent.

FAQs on Why Toilet Bubbles When Flushing

Why is my toilet bubbling after flushing?

If your toilet is bubbling after flushing, it could be a sign that the vent stack is blocked. When the vent stack is blocked, sewer gases get trapped inside, resulting in negative air pressure. When the pressure is more than the toilet bowl can take, the toilet bubbles.

What causes air bubbles when flushing toilet?

Air plays a very important role in the present plumbing system. However, when the toilet bubbles every time you flush it, it might create air bubbles because of the blockage in the vent. If the toilet is not vented properly, it will eventually cause a negative pressure in the system, leading to suction and an airlock.

When flushing upstairs, toilet bubbles downstairs. Why?

There could be reasons why flushing your upstairs toilet causes bubbles downstairs. One reason could be that your home has a poor ventilation system, which is not allowing the air to properly circulate. Another possibility is that there is a blockage in your sewer line, causing the pressure to build up and eventually causing the toilet to bubble.

Final Thought on Why Toilet Bubbles When Flushing

If your toilet bubbles when flushed, you can find it easy to fix or complicated to fix, depending on the cause. Depending on the cause, there are a few different ways that you can fix the problem.

If you have a poor ventilation system, you can try opening windows or using a fan to help circulate the air. If there is a blockage in your sewer line, you will need to contact a professional plumber to fix the issue. In either case, it is always best to consult with a professional before taking on any repairs.



Kristina Perrin

Kristina Perrin

Kristina is an expert DIY home remodeler and mom to three. When she's not cooking or experimenting with new recipes, you can find her working on new home improvement projects or writing about her favorite kitchen appliances or DIY projects on Kitchen Infinity blog.

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