How to Fix a Running Toilet

A constant trickle inside your toilet tank is more than just an annoying sound; it is a drain on your water bill and a sign that your fixture is losing efficiency. When the internal mechanism fails to create a proper seal or shut off the water at the right level, you are essentially pouring money down the drain with every passing hour. Fixing this is a classic weekend win that requires very few tools and no professional training. By focusing on the two main culprits—the flapper and the float—you can usually restore silence and water efficiency in less than an hour. A job well done means a tank that fills quickly, shuts off completely, and stays quiet until the next flush.

1. Check water level first. Remove the tank lid and look at the water level compared to the overflow tube. If water is spilling into the open top of the tube, the float is set too high.
2. Lower the float setting. Locate the adjustment screw on the fill valve or slide the adjustment clip on the float arm downward. This lowers the shut-off point and prevents water from entering the overflow tube.
3. Loosen the flapper chain. Ensure the chain connecting the flush handle to the flapper has a slight amount of slack. If the chain is too tight, it will pull the flapper open just enough to cause a constant leak.
4. Examine the flapper seal. Turn off the water supply valve behind the toilet and flush to drain the tank. Reach in and inspect the rubber flapper for mineral buildup, warping, or dry rot.
5. Replace the faulty flapper. Wipe the rim of the flush valve seat with a cloth to remove mineral deposits that prevent a watertight seal. If the flapper is damaged, unhook it from the pins and snap a new one into place.
6. Verify the seal holds. Turn the water supply back on and allow the tank to refill completely. Listen for the water to stop running and check for any movement in the bowl.