Toilet Bubbling When Flushed? Check This Quick Fix Guide

Is your toilet gurgling, glugging, or bubbling after flushing? That strange sound is never a good sign. Toilet bubbling indicates potential plumbing problems lurking beneath the surface.

But don't panic yet. Oftentimes, a bubbling toilet simply needs a few easy DIY repairs. With some basic troubleshooting, you can stop the annoying gurgles and get your toilet functioning properly again.

Why Is My Toilet Bubbling? Common Causes

First, let's examine some of the most common culprits behind a toilet that bubbles and gurgles after flushing:

Clogged Drain Pipes

When waste and water can't flow freely through the drain pipes, backups and blockages occur. This prevents the toilet from draining properly after flushing. Trapped air and water get forced back up the pipe, causing bubbles, gurgles, and glugs.

Partial clogs from excess toilet paper, debris, and solid waste are often the problem. But full blockages caused by tree roots, collapsed pipes, or stubborn clogs can also lead to bubbling. A drain clog deeper in the main sewer line can back up into the toilet as well.

Clogs around the toilet bend are especially problematic, as are accumulations in the trapway. Hair, grease, toys, paper, wipes, and other debris can clump together and get lodged in drain pipes under the toilet.

Damaged or Faulty Flush Valve

Problems with the flush valve can interfere with the siphoning action needed for a smooth flush. This allows water to back up and bubble back into the bowl.

A worn-out flapper that doesn't seal properly after flushing is a common culprit. Mineral buildup, debris, leaks, and other issues with flush valve parts can also cause water flow problems and bubbling.

Specifically, if the flapper chain is too tight or loose, the flapper may not seat correctly on the flush valve opening. This break in the seal causes water to continuously run from the tank to the bowl, creating bubbles.

Vent Pipe Obstructions

As the toilet flushes, the drain pipe needs air intake through vent pipes. If vents get blocked, air and waste get trapped, unable to drain properly.

Nests, leaves, debris, and ice are common vent pipe cloggers. A blocked vent forces sewer gas backwards, causing gurgles, bubbles, and sometimes a sewage smell .

Vent pipe issues tend to cause bubbling and gurgling with all drains in the house, not just the toilet. Bathtubs, showers, and sinks will be affected too if vent blockages are the cause.

Improper Toilet Installation

An improperly installed toilet can become a bubbling nightmare. If the waste pipe is too long or has curves, it reduces flush power and hinders drainage.

Incorrect toilet/flange height is another issue. The base of the toilet must sit flush on the finished floor for proper functioning.

Using the wrong toilet size or model for your drain line diameter can also impede flushing and cause bubbles.

Low Water Pressure

Inadequate home water pressure leads to a weaker flush and poor siphon creation. The lowered force allows water to bubble back into the bowl rather than fully draining.

Old galvanized supply lines or undersized pipes restrict water flow to the toilet tank, reducing pressure. Partial supply valve clogs have this effect too.

Quick DIY Fixes for a Bubbling Toilet

Before calling a plumber, try these fast fixes you can easily do yourself:

Plunge the Toilet

Grab a plunger and give a few vigorous pumps. This simple plunge can dislodge minor clogs and debris causing the bubbling. Remember to seal the plunger and give a few quick pumps rather than prolonged pushing.

Plunge a few times, then flush to see if the bubbling stops. You may need to repeat the plunging process 2-3 times to clear the clog fully.

Check the Flapper

An out-of-whack flapper is an easy thing to fix. Start by checking for debris, damage, or mineral buildup on the flapper. Clean or replace if needed. Adjust the flapper chain, so it has enough slack but still seals fully.

While you have the tank lid off, check the flush valve seat as well. Debris or misalignment here can allow water to leak through.

Listen for Location

Pay attention to where the bubbling is coming from. Bubbles mainly in the bowl indicate a problem with the flush valve. Gurgles near the toilet base point to a partial drain clog.

Listen closely as you flush to pinpoint the location. Diagnosing the issue based on bubbling location will help you fix it.

Adjust the Fill Valve

If water levels are too high, inadequate siphoning can cause bubbles. Lower the float on the fill valve until the water level drops. This helps the flush fully siphon and prevents backup.

The ideal water level is about 1 inch below the toilet rim. If in doubt, start lower and increase gradually until flushing improves.

Check Supply Valve

Turn off the toilet supply valve and inspect it for clogs or limescale. Clean out any debris with a small brush or toothpick. This ensures strong water flow to refill the tank.

Inspect Water Lines

Check for kinks, corrosion, or leaks in the supply line that runs from the valve to the toilet tank. Replace old, degraded lines to improve water supply.

Resolving Persistent Bubbling with Repairs

For toilets that keep bubbling after flushing despite quick fixes, some repairs are needed:

Snake the Drain

A clog downstream in the main drain line can cause bubbling. Use a closet auger to snake the toilet drain. Insert about 3 feet past the toilet bend.

For deeper clogs, a longer "sink snake" will reach 6-10 feet into the drain. Rotate and remove the auger to pull out any obstructions.

Check the Vent

Inspect vent pipes on the roof and clear any blockages. Remove nests, plants, debris with a wire brush. A hydrojetter can clear hardcore clogs.

Make sure vent screens are clear of debris as well. Unblocking vents resolves many bubbling toilet issues.

Replace Flush Valve Parts

If adjustments don't stop the bubbling, worn-out flush valve parts likely need replacing. This requires shutting off water, disconnecting supply lines, and removing the tank to access the inner valves.

Replacing a faulty flapper, fill valve, tank bolts, seals, and the flush valve assembly can improve flushing power and prevent bubbles.

Upgrade Toilet Model

For a toilet chronically plagued by bubbles despite repairs, installing a newer high-efficiency model is the best solution.

Newer pressure-assisted toilets provide a stronger flush and resistance to clogs and bubbling.