Blog>Expert Advice>Toilet keeps running - Common causes and fixes
Last updated: 4 September 2024
Toilet keeps running - Common causes and fixes
Does your toilet keep running after flushing? There are several reasons why this could be happening. Learn how to get to the root of the problem and how to fix a toilet that won't stop running.
Common causes of a running toilet
Water stains in the toilet bowl and the sound of running water after flushing are both signs of a problem. A running toilet can lead to water wastage and expensive water bills. This plumbing problem can also result in a flooded bathroom or overflowing septic tank.
Spotting the signs of a running toilet is easy. Unfortunately, finding the cause of the problem can be a little more tricky.
The most common causes of a running toilet include:
A faulty fill valve - This component controls the water levels in the toilet's tank. The water flow can continue after flushing if the fill valve is faulty and not closing correctly
A leaking flapper - This rubber seal controls water flow from the tank into the toilet bowl. A deteriorated or poorly fitted flapper can allow the toilet to keep running after you flush
Too short/too long chain - There is a chain connecting a toilet's flapper to the flush handle. Toilets can continue to run if the chain is too long or too short as this can stop the flapper from fully sealing
There are several working parts inside a toilet's cistern. Any faulty, wrong sized or poorly installed components can lead to refilling and overflowing problems.
Working out why your toilet won't stop running
Before you can fix a running toilet, you first need to get to the source of the problem.
The following factors will determine the type of repair work you need:
Type of cistern
Type of flusher
Which components are damaged, faulty or in the wrong position
Different toilets work in different ways. For instance, push-button and handle or chain flush toilets use different mechanisms. Due to these differences, it is not always easy to work out exactly why a toilet keeps running after flushing.
Getting to the bottom of this problem can be more difficult than you expect. Without experience, you may cause leaks to get worse or end up damaging important components.
It can also be difficult to gain access to the inside of a toilet's cistern. Finding out why a wall-hung or traditional high-level cistern keeps refilling the toilet can be particularly challenging.
A professional plumber will be able to access your toilet's cistern and correctly diagnose the problem.
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If you want to try a DIY fix before hiring an expert, we recommend following these steps:
Check the fill tube
The fill tube is responsible for refilling the toilet bowl after flushing. It is a small, bendy tube connected to the fill valve and hovering just above the overflow tube.
After flushing, the fill tube squirts water into the overflow tube. If the fill tube is not correctly positioned, the water can miss the overflow tube, and the toilet will continue to run.
This problem has a fairly straightforward fix. Make sure the fill tube is firmly connected to the fill valve and positioned correctly above the overflow tube. This may be all that is needed to stop your toilet from running after flushing.
Check the water level
The majority of toilets have a water level fill marker inside the tank.
Flush your toilet and check to see if the water is rising high enough. If not, the float in the cistern will not reach the correct level to stop the toilet from running.
Typically, this problem can be solved by adjusting the mechanism responsible for sensing the water levels. This may by a ballcock float in older toilets or a syphon in newer models.
Check the float
A clogged float can cause a toilet to keep running after flushing.
Make sure that the float isn't full of water. Carefully remove the float from the cistern and shake it. If you can hear water inside, this part will need to be replaced.
Check the flapper
The toilet flapper creates a seal between the water tank and toilet bowl.
When you flush the toilet, the flapper opens to allow water to refill the system. The flapper then closes to create a seal between the tank and bowl.
Flappers can deteriorate or move over time, so check for signs of damage or misalignment. You may need to reposition the flapper to stop your toilet from running.
A damaged or worn flapper will need to be replaced. Alternatively, adjusting the length of the chain attached to the flapper may be all that is needed to fix the problem.
Flush the toilet after making any adjustments to see if your DIY running toilet repair has been successful.
It takes approximately 10 to 15 seconds for a toilet to refill after flushing. Contact a local plumber if you notice your toilet running for longer.
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How to fix a toilet that keeps running
Adjusting the different components of a toilet isn’t always enough to stop water from running after flushing. If your DIY attempts haven't worked, the fill valve, flapper or syphon may need to be replaced.
Avoid replacing toilet components if you do not have the necessary tools, skills and experience. Instead, we recommend hiring a plumber to fix your running toilet.
An experienced tradesperson can take your toilet apart and check if all the different mechanisms are working correctly.
Deteriorated parts can easily be replaced by an experienced plumber. Investing in professional repairs now will help you to avoid sky-high water bills in the future!
How much does it cost to fix a toilet that keeps running?
Plumbers charge varying fees for toilet repairs. Your final price will be determined by how long the repair work takes and if any replacement parts are needed.
On average, plumbers charge an hourly rate of£50. Or, they may charge a day rate of around £350, Or, they might charge per job.
Running toilets can cause flooding in your home or septic tank. You will likely need the immediate help of an emergency plumber if water is spilling out of your toilet. The average call out fee for an emergency plumber is £100.
Take a look at our plumber cost guide for more information.
Key takeaways
Running toilets are typically caused by faulty, deteriorated or misaligned parts inside the cistern
It is not always easy to determine exactly which component is causing the toilet to keep running
Signs of a running toilet include continuous noise after flushing, water staining on the side of the bowl and increased water bills
You will need to lift the lid off the cistern to check the different components for damage
A faulty flapper or malfunctioning fill valve are common causes of a running toilet
An experienced plumber can find the cause of the problem and stop the toilet from running after flushing
Plumbers charge an average hourly rate of £50
Hiring a high quality local plumber
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See the tradespeople we've checked and recommend for your job
See the tradespeople we've checked and recommend for your job