How to Fix a Running Toilet

Is your toilet running? No, we don’t mean it’s out for a jog! A running toilet refers to a common plumbing issue where water continues to flow into the toilet bowl even when it’s not being used. This not only wastes water but also leads to higher water bills. However, don’t worry! In this comprehensive guide, we’ll walk you through the steps to fix a running toilet on your own. No need to call a plumber just yet!

Understanding the Anatomy of a Toilet

Before diving into the troubleshooting steps, let’s familiarize ourselves with the key components of a toilet. Understanding how everything works together will help you diagnose and fix the problem more effectively. Here are the main parts:

  1. Fill Valve: This valve controls the water supply to the toilet tank.
  2. Flush Valve: The flush valve, also known as the flapper valve, releases water from the tank into the bowl during a flush.
  3. Overflow Tube: Located in the center of the tank, the overflow tube prevents the tank from overflowing by directing excess water into the bowl.
  4. Float: The float regulates the water level in the tank by signaling the fill valve when to stop filling.
  5. Handle and Chain: The handle triggers the flush mechanism, which lifts the flapper valve via a chain.

Troubleshooting a Running Toilet

Now that you’re familiar with the toilet’s components, let’s diagnose the issue and fix your running toilet. Follow these step-by-step instructions:

Step 1: Identify the Problem

The first step is to determine the cause of the running toilet. It could be due to:

  1. A flapper valve that doesn’t seal properly.
  2. A fill valve that doesn’t shut off completely.
  3. A faulty float that doesn’t control the water level correctly.
  4. A leaking flush handle.

Step 2: Turn Off the Water

Before starting any repairs, turn off the water supply to the toilet. Locate the shut-off valve near the base of the toilet and turn it clockwise until it’s fully closed. This prevents any further water from entering the tank.

Step 3: Adjust the Flapper Valve

The most common cause of a running toilet is a faulty flapper valve. To fix it:

  1. Remove the toilet tank lid and locate the flapper valve.
  2. Check if the flapper valve is worn out or misaligned.
  3. If it’s misaligned, reposition it so that it fully covers the flush valve opening.
  4. If it’s worn out, replace it with a new flapper valve, ensuring it matches your toilet model.
  5. Make sure the chain connecting the flapper valve to the flush handle has enough slack but isn’t overly loose.

Step 4: Check and Adjust the Fill Valve

If adjusting the flapper valve didn’t solve the problem, the fill valve might be the culprit. Follow these steps:

  1. Locate the fill valve, usually on the left side of the tank.
  2. Check if the fill valve is fully closing. If it continues to let water flow, it needs adjustment or replacement.
  3. Adjust the fill valve according to the manufacturer’s instructions, usually by turning an adjustment screw or knob.
  4. Test the water level by flushing and observing if it stops at the appropriate level. Make further adjustments if needed.

Step 5: Inspect the Float

If the fill valve adjustment didn’t work, the float might be causing the issue. Perform the following:

  1. Examine the float to ensure it moves freely and isn’t stuck in a raised position.
  2. If it’s stuck, clean it and the area around it to remove any debris or mineral deposits.
  3. If the float is damaged or doesn’t function properly, consider replacing it with a compatible float assembly.

Step 6: Check the Flush Handle

If the toilet is still running, it’s time to examine the flush handle:

  1. Test the handle to see if it returns to its original position after flushing. If it doesn’t, it may need adjustment or replacement.
  2. Look for any loose connections or broken parts between the handle and the flapper valve chain.
  3. Tighten or replace any faulty components as necessary.


Congratulations! You’ve successfully fixed your running toilet without the need for professional assistance. By understanding the key components and following the troubleshooting steps outlined in this guide, you were able to diagnose and resolve the issue. Remember to turn on the water supply again and test your toilet to ensure it’s working properly.




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