A flushing toilet makes a very specific sound, and when it does something out of the ordinary, it’s hard not to notice. Gurgling is not an unusual complaint from a toilet, but it shouldn’t be ignored. If your toilet gurgles when you flush it or on its own, you may also notice water bubbling back up into the bowl. And at some point, you might have witnessed the strangest symptom of all: a toilet that flushes itself.

It’s very important to resolve these symptoms because what’s next is worse: a backup. This is likely to come from your toilet, but it can also happen in tubs. The mess of a backup and an overflow is likely to be way more costly than solving the issue of your gurgling toilet.

hands plunging toilet

What Causes a Toilet to Gurgle or Bubble When Flushed?

Bubbles in the toilet, a toilet that drains slowly, or one that gurgles is telling you something specific: You have a blockage. For water and waste to flow through your pipes, the air pressure has to be just right. A block causes negative air pressure, or suction, in your plumbing. When the air escapes back up into the toilet, it makes a gurgling noise or causes the water to bubble.

The blockage could be in one of four places:

1. The Toilet Itself

If your toilet is blocked, you can probably see it. There’s shredded toilet paper—and other things—floating in the water.

2. The Toilet’s Drain

This often happens when you or members of your family flush things down the toilet that they shouldn’t, like feminine protection products or cotton swabs.

3. The Main Sewer Drain

The main sewer drain is where all the drains in your house lead—from the kitchen, bathroom, laundry room, and more. It carries waste and water away from your property to the city sewer system.

Blocks in main sewer lines are most often caused by things outside your control, like:

  • Roots growing through the pipes underground
  • Segments of pipe separating from one another
  • A pipe growing a “belly” because of shifting or settling ground

4. The Vent Stack

When a plumbing appliance malfunctions, most people look underground, but in this case, looking up may lead you to the answer. The vent stack is on your roof, and it doesn’t just dispel smelly sewer odors from your home; it’s also equalizes the air pressure in your pipes, so water and waste can move through them freely.

Sometimes the vent pipe gets clogged by leaves or even a deceased animal, which causes negative air pressure and a bubbling toilet.

4 Solutions to a Gurgling Toilet

The answer to a gurgling, bubbling toilet depends on the source of the problem. Find it by doing the following:

1. Take a Plunger to Your Toilet

Before you plunge, seal off nearby drains, so the air in your pipes doesn’t escape that way. You want it to escape through your toilet when you plunge, bringing up with it any clog that’s there. You can use duct tape to seal off sinks, the tub, etc.

A plunger can usually take care of light-to-moderate clogs.

2. Snake the Drain

If you plunge the toilet and don’t bring up a clog or the problem continues, try snaking your drain through the toilet bowl. A drain snake (auger) is something every homeowner should have in their plumbing toolbox. A standard snake can reach 5 to 15 feet into your drain and clear many of the clogs a plunger can’t.

If more power is needed, you can rent a motorized auger, which can reach 100 feet or more. To use a motorized snake, you’ll need to remove your toilet from its base. If you don’t feel comfortable doing so, call a plumber. They know when a drain-cleaning solution needs to be escalated and can minimize risks to your toilet and your home’s plumbing.

3. Call Your Neighbors

It sounds like an odd thing to do for a plumbing problem, but if one or more of your neighbors also has a gurgling or bubbling toilet, the problem is likely in the sewer main. That’s the responsibility of the city sewer authority. Give them a call, and they should come out to do an inspection. Any problem they find with their pipe will be repaired on their dime.

4. Call a Plumber

The solutions above may solve your problem, but if the clog is large or located deep within your plumbing, you likely won’t be able to DIY your way out of it. That’s where a licensed, experienced plumber can step in. Besides being able to easily clean drains, he or she has specialized tools, like a camera that can inspect from tens to hundreds of feet into your pipes. He can use a powerful auger to chop through tree roots, if necessary. In severe cases, it might be necessary to remove part or all of your sewer pipe. A reputable plumbing company can take care of sewer line repair and line replacement. And depending on the slope of your roof, a plumber may be able to climb up and clean out a clogged vent stack.

Keep Your Toilet Quiet by Preventing Problems

There are several simple things you can do to help keep your pipes clear and your toilet in working order:

  • Only flush water, waste, and toilet paper – Click here for a list of nine things you should never flush down the toilet.
  • Protect your vent stack from foreign objects – Cover it with hardware cloth secured with a hose clamp to keep out leaves, animals, and other debris.
  • Get your plumbing inspected regularly – An annual inspection like C&W Plumbing’s 14-Point Inspection can keep potential problems at bay and make sure all systems are go.