How to Stop an Overflowing Toilet and Prevent Water Damage

An overflowing toilet can quickly turn into a messy and potentially damaging situation. From water damage to mold growth, the consequences can be serious. It’s crucial to address the problem promptly and take the necessary steps to stop the water flow. In this article, we will guide you through the process of stopping an overflowing toilet, diagnosing the issue, and preventing future occurrences.

How to Stop an Overflowing Toilet and Prevent Water Damage

Stopping the Water Flow

The first step in handling an overflowing toilet is to stop the water from flowing. There are a few methods you can try:

  • Turn off the water supply to the toilet: The water supply valve is usually located behind the toilet on the wall. Tighten the valve to shut off the water flow.
  • Lift the float: If turning off the water supply doesn’t work, remove the lid of the toilet tank and lift the float that’s at the water’s surface. This should stop the flow of water.
  • Shut off the main water supply: If the water continues to flow even after lifting the float, it’s likely a sewage backup. In this case, shut off the main water supply to your house by closing the main valve outside near the street or by your water heater.

Understanding How Your Toilet Works

Before attempting to fix the overflowing toilet, it’s helpful to understand how toilets work. While there may be variations in materials and component shapes, the fundamentals remain the same.

  • Triggering the flush: To initiate a flush, you either push a button or a handle. This action lifts a chain connected to a stopper, exposing the flush valve. Gravity then pushes water down through the valve and into the toilet bowl, washing away its contents.
  • Refilling the tank: As the tank empties, the float bobber connected to the fill valve sinks. This opens the fill valve, allowing water to refill the tank. Once the tank reaches the desired level, the float bobber rises and shuts off the fill valve.
  • Overflow safety feature: Toilets are equipped with an overflow tube inside the tank. If the water level in the tank becomes too high, the overflow tube drains excess water into the bowl. Constant water running or noise from the toilet may indicate a high water level issue.

Troubleshooting an Overflowing Toilet

Once you have successfully stopped the water flow, it’s time to clean up the area and start troubleshooting the issue causing the overflow. Understanding the common failure points can help you diagnose and potentially fix the problem yourself.

  • Checking the float: If the float has come loose, it can lead to an overflow. Remove the tank lid and check if the float is connected to anything. If it’s free-floating, lift the lever to seal off the fill valve, then reconnect the float to the end of the lever.
  • Examining the fill valve seal: A cracked or loose seal can prevent the fill valve from closing properly, causing continuous water flow. If the seal appears to be the issue, it’s best to call a professional plumber for assistance.
  • Inspecting the overflow tube: An incorrect size or alignment of the overflow tube can result in water constantly draining into the bowl. If you suspect the tube is the problem, it’s advisable to seek professional help.

Adjusting the Water Level in the Toilet Tank

An incorrect water level in the toilet tank can lead to frequent overflows. Adjusting the water level is a simple task that can be done by following these steps:

  • For ballcock floats: Older toilets may have a ballcock float attached to the lever. Adjust the height of the ballcock by gently bending the brass lever up or down. Newer plastic models often have an adjustment screw at the top of the fill valve. Turning it counter-clockwise lowers the water level, while turning it clockwise raises the level.
  • For cup floats: Cup floats, also known as concentric valves, have adjustment rods to maintain the correct water level. Locate the cup valve at the top of the fill valve and find the adjustment rod connected to the float. Pinch the float clip to release the float and slide the cup up or down to adjust the water level.

Identifying Toilet Tank Leaks

It’s important to differentiate between an overflowing toilet and a toilet tank leak. Understanding the problem can help you take appropriate action. Common areas where leaks occur include the spud washer, fill valve, and bolt gaskets.

  • Spud washer leaks: The spud washer, located between the tank and the bowl, can deteriorate over time. If the leak worsens during flushing, the spud washer may need repair or replacement.
  • Fill valve leaks: The fill valve tube, running from the toilet into the tank, can develop leaks at various points. If turning off the water supply stops the leak, the fill valve tube is likely the culprit. Fill valve issues can also cause double flushing.
  • Bolt gasket leaks: The two bolts that connect the toilet tank to the rest of the toilet have gaskets that can decay. Slow but steady leaks can occur if the gaskets are damaged.

Calling a Professional Plumber

While some toilet issues can be resolved independently, others require the expertise of a licensed plumber. If you’re uncertain about making repairs yourself or if the problem involves more complex components, it’s best to seek professional help. Plumbers have the knowledge and experience to handle plumbing emergencies efficiently and can ensure that repairs are done correctly.


Preventing Future Toilet Overflows

Once you’ve resolved the immediate issue, it’s essential to take preventive measures to avoid future toilet overflows. Here are some tips:

  • Regular maintenance: Inspect your toilet periodically for any signs of leaks or malfunctions. Addressing issues early can prevent more significant problems later.
  • Educate household members: Teach everyone in your household about proper toilet use, including not flushing items that can clog the system.
  • Avoid excessive toilet paper: Use an appropriate amount of toilet paper to minimize the risk of clogs.
  • Proper disposal: Dispose of feminine hygiene products, wipes, and other non-flushable items in the trash, not in the toilet.
  • Upgrade your toilet: Consider replacing older toilets with newer models that are more efficient and less prone to overflows.


An overflowing toilet can be a stressful situation, but with the right steps, you can stop the water flow, troubleshoot the issue, and prevent future occurrences. Understanding how your toilet works, adjusting the water level, and identifying potential leaks are essential in resolving the problem. While some repairs can be done independently, don’t hesitate to call a professional plumber for more complex issues. By taking preventive measures, you can minimize the risk of future toilet overflows and maintain a functioning and efficient toilet system in your home.

If you’re facing water damage issues, whether from an overflowing toilet or any other source, Elite Restoration Group is your go-to solution. Our expert team specializes in comprehensive water damage restoration services, ensuring a swift and effective recovery for your property.

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