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April 29, 2024

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Why does my toilet keep running and what can I do about it

If you find yourself constantly hearing the sound of running water from your toilet, you're not alone. A running toilet is a common plumbing issue that can lead to wasted water and higher bills if left unaddressed. At Sewer Surgeon, we understand the frustration that comes with a perpetually running toilet, which is why we're here to provide you with insights into why it happens and what you can do to fix it.

Why Does My Toilet Keep Running?

There are several potential reasons why your toilet might be running continuously. Understanding these causes can help you diagnose the problem more effectively and determine the appropriate course of action. Here are some common reasons why toilets keep running:

1. Faulty Flapper Valve

The flapper valve is responsible for sealing the flush valve opening and preventing water from continuously flowing into the bowl. If the flapper is worn out or damaged, it may not seal properly, allowing water to leak into the bowl and causing the toilet to run.

2. Issues with the Float

The float, also known as the ballcock or fill valve, regulates the water level in the toilet tank. If the float is set too high, it can cause the tank to overfill and trigger the toilet to run continuously. Similarly, if the float is damaged or malfunctioning, it may not shut off the water supply properly.

3. Worn Out Seals

The toilet tank contains various seals and gaskets that help maintain a watertight seal. Over time, these seals can deteriorate or become damaged, leading to leaks and a running toilet.

4. Broken Fill Valve

The fill valve is responsible for refilling the toilet tank after each flush. If the fill valve is broken or malfunctioning, it may continuously allow water to flow into the tank, causing the toilet to run.

5. Improperly Adjusted Chain

The chain that connects the flush handle to the flapper valve can become tangled or improperly adjusted, preventing the flapper from sealing properly and causing the toilet to run.

What Can I Do About It?

Fortunately, many running toilet issues can be resolved with some basic troubleshooting and repairs. Here are some steps you can take to fix a running toilet:

  • Check the Flapper Valve

Inspect the flapper valve for signs of wear or damage. If the flapper is warped, torn, or covered in mineral deposits, it may need to be replaced. Ensure that the flapper is properly seated over the flush valve opening and creates a tight seal when closed.

  • Adjust the Float

Adjusting the float in your toilet tank is a simple yet effective way to address a running toilet. If the water level is too high, it can lead to continuous water flow into the overflow tube, causing the toilet to run constantly. To adjust the float, locate the float adjustment screw, which is typically located on top of the fill valve. Turn the screw clockwise to lower the float and decrease the water level, or counterclockwise to raise the float and increase the water level. Ensure that the float is positioned at the recommended level, usually indicated by a marked line on the fill valve or specified in the manufacturer's instructions. By properly adjusting the float, you can prevent excess water from entering the tank, thereby resolving the issue of a running toilet and conserving water usage in your home.

  • Inspect and Replace Seals

Inspecting and replacing seals in your toilet tank is crucial for maintaining its proper functionality and preventing water wastage due to leaks. Begin by examining the seals and gaskets inside the tank for any signs of wear, deterioration, or damage. Common areas to inspect include the flush valve seal, tank-to-bowl gasket, and inlet valve seal. Look for visible cracks, tears, or areas where the seals appear worn out or degraded.

If you notice any signs of damage or wear, it's essential to replace the affected seals promptly. Start by turning off the water supply to the toilet and flushing to drain the tank completely. Once the tank is empty, remove the bolts securing the tank to the bowl and carefully lift the tank off the bowl to access the seals underneath.

Inspect the flush valve seal, which is located at the bottom of the tank and creates a watertight seal between the tank and the toilet bowl during flushing. If the flush valve seal appears worn, cracked, or distorted, it's best to replace it with a new one to prevent water leakage.

Next, check the tank-to-bowl gasket, which seals the connection between the toilet tank and the bowl. Look for any signs of damage or deterioration, such as flattened or compressed areas, which can compromise the seal. If the gasket is damaged, remove it and install a new one to ensure a proper seal between the tank and bowl.

Finally, inspect the inlet valve seal, also known as the fill valve seal, which is located at the base of the fill valve inside the tank. This seal prevents water from leaking out of the tank through the fill valve. If the seal appears worn or damaged, replace it with a new one to maintain a watertight seal and prevent water wastage.

After replacing any worn-out seals, carefully reassemble the toilet tank, ensuring that all bolts and connections are tightened securely. Turn the water supply back on and allow the tank to fill completely. Check for any signs of leaks around the seals and connections, and make adjustments as needed to ensure a watertight seal.

Regularly inspecting and replacing seals in your toilet tank is essential for preventing water leaks and maintaining efficient water usage. By taking proactive measures to address seal issues, you can prolong the lifespan of your toilet and avoid costly water damage repairs in the future.

  • Replace the Fill Valve

If the fill valve is malfunctioning, consider replacing it with a new one. Fill valves are relatively inexpensive and easy to install, and replacing a faulty fill valve can often solve the problem of a running toilet.

  • Adjust the Chain

Ensure that the chain connecting the flush handle to the flapper valve is properly adjusted. The chain should have some slack to allow the flapper to close fully when the toilet is not in use.


A running toilet is not only a nuisance but also a waste of water and money. By understanding the common causes of toilet running issues and following these troubleshooting tips, you can effectively diagnose and fix the problem. However, if you're unsure about how to proceed or if the problem persists, don't hesitate to contact the experts at Sewer Surgeon for professional assistance. Let us help you put an end to your toilet troubles and ensure efficient and reliable plumbing in your home.

Frequently Asked Questions

Q, How do I know if my toilet is running?

If you hear the sound of running water in your toilet when it's not in use, or if you notice water constantly trickling into the bowl, your toilet is likely running.

Q. Can a running toilet cause water damage?

Yes, a running toilet can lead to water damage if left untreated. Continuous water flow can oversaturate the floor around the toilet, damage flooring materials, and even cause structural issues over time.

Q. Why does my toilet keep running after I flush it?

A toilet may continue running after flushing due to issues such as a faulty flapper valve, a malfunctioning fill valve, or improper adjustment of the float.

Q. Will a running toilet increase my water bill?

Yes, a running toilet can significantly increase your water bill by wasting large amounts of water over time. Addressing the issue promptly can help prevent unnecessary expenses.

Q. Can I fix a running toilet myself, or do I need a plumber?

Many running toilet issues can be resolved with DIY repairs, such as adjusting the float or replacing the flapper valve. However, if you're unsure or the problem persists, it's best to consult a plumber for professional assistance.