Skip to main content

How to Fix a Running Toilet

Is a constantly running toilet driving you mad? Don’t call the plumber until you try these simple adjustments.


  • Step 1: Look inside tank Get to know your toilet. Lift the cover of the tank to see what's inside. At the bottom of the water, either a ball or a flapper will be covering a valve that lets water into your toilet bowl when you flush. Flush the toilet to see the valve at work -- the problem may become obvious.
  • Step 2: Check to see if the valve is covered If you see that the ball or flapper is not completely covering the valve, investigate what’s prohibiting it from doing so. The chain or rod that pulls it open might be twisted, bent, or caught on something. Or the flapper or ball itself might be damaged or corroded, keeping it from making a solid seal; you'll need to replace it.
  • TIP: If the valve appears to be covered but the tank never seems to fill, you might have a slow leak. Put a little food coloring in the tank; if it seeps into the bowl, you'll need to replace the flapper or ball.
  • Step 3: Find the float If the valve is completely covered but the water continues running, you need to lower the float. The float is the piece that moves up and down with the water level in the tank. The float will be either a closed cup that encircles a tall tube or a rubber ball at the end of a long metal arm. Find your float.
  • TIP: Lowering the float will lower the water level in the tank and keep it from rising above a safety mechanism called the overflow pipe, which is the open-topped tube sticking up in the tank. Normally, the water level isn't supposed to reach the rim of the pipe, but if it's set too high, water will run through the pipe into the toilet bowl.
  • Step 4: Lower the float Lower the float. If you have a float cup, squeeze the metal clip attached to it and slide the clip down so it's below the water level. If you have a ball float, either tighten the screw at the end of the arm opposite the ball, or bend the arm downward.
  • Step 5: Do a test flush Flush the toilet to test the new water level. If it still rises above the overflow pipe, lower the float some more. If the water gets too low for an adequate flush, just raise the float until you get it just right.
  • TIP: Usually, the water level should reach about an inch below the rim of the overflow pipe.
  • Step 6: Replace parts if necessary Before replacing damaged parts, shut off the water to your toilet by locating the valve in the wall behind it & turning it clockwise. Flush the toilet & remove the part; then take it with you to the store to ensure you buy an exact match. The sound of running water is now a thing of the past -- and you’ll have the lower water bill to prove it!
  • FACT: The average person visits the toilet 2,500 times a year.

You Will Need

  • A faulty toilet
  • Food coloring

Popular Categories