Why Is My Toilet Gurgling? Common Causes and What to Do

A gurgling toilet can be an early warning that air and wastewater are struggling to move through your drainage system. You may hear bubbling after flushing, when using a nearby sink or even when no one is using the toilet.

Sometimes the cause is a minor blockage close to the toilet. However, persistent gurgling—particularly when several fixtures are affected—can indicate a blockage deeper within the property’s drainage system.

What Causes a Toilet to Gurgle?

A drainage system needs water and air to move freely. When a pipe is partially blocked, air can become trapped and escape through the toilet bowl, creating bubbles or gurgling sounds.

Common causes include:

A partially blocked toilet

Excessive toilet paper or an unsuitable item may restrict the toilet outlet without blocking it completely. Water may still drain, but more slowly than normal.

A blockage deeper in the drain

Waste, wet wipes, grease and other debris can create an obstruction further along the drainage pipe. Air displaced by wastewater may then return through the toilet.

A blocked drainage vent

Drainage vents allow air to enter the system and help wastewater flow correctly. A blocked or damaged vent can create pressure changes that cause toilets and plugholes to gurgle.

A blocked shared drain or sewer

If several toilets, sinks or showers are affected, the problem may be within a shared pipe or main sewer rather than the individual toilet.

Tree roots or damaged pipework

Tree roots can enter underground drains through cracks or loose joints. Older pipes may also become misaligned, cracked or collapsed, restricting the flow of wastewater.

What Other Warning Signs Should You Check?

Gurgling alone may not reveal the full extent of the problem. Look for other drainage warning signs, including:

• Toilet water rising unusually high after flushing
• Water draining slowly from sinks or showers
• Unpleasant sewage smells
• Water returning through another plughole
• An outside drain overflowing
• Bubbles appearing when a nearby tap is used
• The toilet taking longer to empty
• The same problem repeatedly returning

If water is backing up into your property, stop using the affected fixtures and contact a drainage professional.

What Should You Do If the Toilet Water Is Rising?

Do not continue flushing. Repeated flushing could cause the toilet to overflow.

Wait for the water level to fall and keep children and pets away from the area. If the water remains high or contains sewage, avoid contact and arrange professional assistance.

How to Plunge a Toilet Safely

A plunger may clear a minor blockage located close to the toilet.

Use a toilet plunger with a flange designed to fit inside the toilet outlet:

1. Put on waterproof gloves.
2. Ensure there is enough water to cover the rubber part of the plunger.
3. Position the plunger firmly over the outlet.
4. Begin with gentle pressure to remove trapped air.
5. Use several steady plunging movements.
6. Remove the plunger and allow time for the water level to settle.
7. Test with a small amount of water before flushing normally.

Avoid excessive force, as this could damage the toilet seal or push a solid object deeper into the pipe.

Stop if the water level rises or the blockage does not improve.

What Should Never Be Flushed Down a Toilet?

To reduce the risk of future blockages, only flush toilet paper and human waste.

Do not flush:

• Wet wipes, including those described as flushable
• Sanitary products
• Nappies
• Cotton buds
• Dental floss
• Paper towels
• Kitchen roll
• Cleaning cloths
• Food waste
• Cooking oil or grease
• Cat litter

These materials may not break down and can collect inside the drainage system.

Should You Use Chemical Drain Cleaner?

Chemical drain cleaners are generally unsuitable for toilets. They may damage components, remain trapped in the bowl or create a hazard for anyone attempting to clear the blockage.

Never mix cleaning products. Combining bleach, acids, ammonia or drain cleaners can produce dangerous fumes.

If chemicals have already been used, tell the drainage engineer before they start work.

Why Does My Toilet Gurgle When the Sink or Shower Drains?

This can indicate that the fixtures share part of the same drainage pipe.

When water passes an obstruction, trapped air may be pushed towards the toilet. The air then escapes through the bowl and produces a gurgling sound.

If several fixtures are slow, noisy or producing unpleasant smells, the problem is likely to be deeper than the individual toilet.

Why Does the Problem Keep Returning?

A blockage that repeatedly returns may be caused by:

• Wet wipes or other solid waste
• An obstruction deeper inside the pipe
• Tree-root intrusion
• A cracked or collapsed drain
• Misaligned pipe joints
• Poor drainage fall
• A blocked vent
• A problem within a shared drain

A CCTV drain survey can inspect the inside of the pipe and identify the precise cause without unnecessary excavation.

When Should You Contact Better Drains?

Arrange professional assistance if:

• Plunging has not resolved the problem
• The toilet water continues to rise
• Sewage is backing up
• Several fixtures are affected
• An outside drain is overflowing
• Gurgling repeatedly returns
• You notice persistent sewage smells
• You suspect roots or damaged pipework
• An object may be trapped inside the toilet

Professional drain-clearance equipment can safely remove deeper obstructions. If pipe damage is suspected, a CCTV inspection can establish whether cleaning, relining or repair is required.

How Can You Prevent a Gurgling Toilet?

You can reduce the risk of future drainage problems by:

• Only flushing toilet paper
• Using smaller amounts of toilet paper when necessary
• Keeping wipes and sanitary products out of the toilet
• Investigating slow drainage promptly
• Avoiding chemical drain cleaners
• Arranging an inspection if the problem repeatedly returns
• Keeping outside drain covers clear of leaves and debris

Need Help With a Gurgling or Blocked Toilet?

A gurgling toilet may be the first sign of a developing blockage. Acting early can help prevent wastewater from backing up or overflowing.

Better Drains can identify and clear toilet and drainage blockages using professional equipment. Contact our team if the problem persists or affects multiple parts of your property.

Frequently Asked Questions

Is a gurgling toilet serious?

Occasional gurgling may result from a local obstruction. Persistent noises, rising water or several affected drains can indicate a more serious blockage.

Why does my toilet bubble when I use the sink?

The toilet and sink may share a drainage pipe. A blockage can displace trapped air, which escapes through the toilet bowl as bubbles.

Can I use a plunger on a gurgling toilet?

Yes, a toilet plunger may clear a minor blockage near the outlet. Stop if the water level rises or there is no improvement.

Why is my toilet water rising after flushing?

Water rises when it cannot pass through the outlet quickly enough. Stop flushing, as another flush may cause an overflow.

Do I need a CCTV drain survey?

A survey may be recommended when the problem repeatedly returns or when roots, pipe movement or structural damage are suspected.