Blog>Expert Advice>Why is my drain making a gurgling sound?
Last updated: 27 September 2024
Why is my drain making a gurgling sound?
Is your drain making a gurgling sound? Find out what’s causing this plumbing problem, and what to do about it.

Why is my drain gurgling?
A gurgling drain is not your drain's way of talking back at you!
Instead, something is preventing water or air from flowing through your drain.
A blockage slows the water's travel through your drains. This clog creates a vacuum and air bubbles, creating a gurgling sound.

Common drain problems
A gurgling drain is usually due to a minor plumbing issue, but it can also signal a bigger problem with your drains.
Understanding why your drain is gurgling can prevent further plumbing problems.
Things that can lead to a gurgling drain include:
Blocked drains
A blocked drain is usually due to food, grease, minerals, hair, soap, or debris.
The blockage might be in one or several places, depending on where you hear the gurgling sound.
For example, if the gurgling sound comes only from your kitchen sink, the problem is probably with that drain.
Or, gurgling in all drains could signal a problem with the main sewer line.
Find a drain service near you to help with a blocked drain.
Blocked or damaged P-Trap
This is the U-shaped pipe you see under your sink. Your sink cannot function properly without it.
A P-Trap creates a barrier to stop sewer smells from entering your house.
When you hear your drain gurgling, it can be due to a blocked or damaged P-Trap.
It's relatively easy to unblock your P-Trap.
But you may have to replace a damaged P-Trap.

Blocked or damaged vent pipe
Your vent pipe ensures proper air pressure regulation and air circulation. Letting air escape prevents pressure from building up in your pipes.
Leaves, bird nests, rust, corrosion, rodents, and other debris can block your vent pipe.
A gurgling drain is caused by the air being forced to find another way out due to a clog or damaged vent.
Blocked sewer line
The water from your home's plumbing can't drain properly with a blocked sewer line.
Blocked sewer lines can lead to clogs in multiple drains. Blockages can be caused by anything from tree roots to baby wipes.
Even if your sewer line is only partially blocked, this is a serious plumbing problem.
The pressure imbalance that forces air bubbles back through your pipes results in a gurgling sound in your sink, shower, or toilet drains.
How do you fix a gurgling drain?
How you fix your gurgling drain depends on the problem nature of the problem.
You might be able to fix your drain yourself or need the help of a good plumber.
Follow these steps to fix a gurgling drain:
Identify the problem
Listen to where the gurgling sound is coming from
If the sound only comes from one drain, then the clog is only in that drain line
If the sound comes from multiple or all our drains, the clog is probably in your main sewer line
To test, open the tap in your kitchen sink and see if the tap in your bathroom gurgles
If so, a clog in the main sewer line is the likely culprit
Clear your sink drains
Use a plunger to clear any blockages
A drain auger (plumber's snake) is next when a plunger fails
Remove the blockage with tweezers or pliers if hair buildup is high enough up your drain
Try the old baking soda and vinegar solution: Pour a cup of baking soda down your drain, followed by half a cup of vinegar. Pop a cloth or plug over the drain and let foam for 30 to 60 minutes before running hot water down the drain for 2 to 3 minutes
A drain hair catcher might be worth investing in to prevent hair from getting into your drain.
Drain repair cost
The average drain gurgling repair cost depends on the cause and the tools your plumber needs.
For example:
Drain unblocking costs start from £75per project
Drain repair costs are usually between £450 - £750
Main sewer line repair costs start at £180
Drain cleaning starts at £120
CCTV drains surveys cost between £150 - £400
What's the average cost of unblocking a drain?
In this drain unblocking cost guide, we outline the typical cost of unblocking a drain - including drain jetting, rodding and lining prices.
See the tradespeople we've checked and recommend for your job
FAQs
Why is my outside drain bubbling?
Like a gurgling drain, an outside drain bubbling also suggests a blockage in your plumbing system.
Air becomes trapped in the pipes and moves through them, causing a gurgling sound.
Why is my sink gurgling without blockage?
If your gurgling sink has nothing to do with a blocked drain, it's a good idea to call a professional to investigate.
What do plumbers use to unblock drains?
Plumbers use a range of tools and methods to unblock drains, such as:
Plungers to clear simple clogs in sinks, toilets, and drains
A drain auger/plumber’s snake to break down tougher blockages in pipes and drains
Hydrojetting to clear difficult clogs, like tree roots in sewer lines
CCTV drain surveys get to the root of the issue
Biological drain cleaners to break down organic material without damaging pipes

Does pouring boiling water down a drain help unclog it?
Pouring boiling water down a drain might loosen the clog, but it could do damage.
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