How to Fix a Running Toilet

Stop your toilet from running constantly by checking and replacing a few cheap parts inside the tank.

1. Remove the tank lid and check the flapper

   The flapper is the rubber seal at the bottom of the tank. If it looks warped, cracked, or doesn't sit flush, it's letting water leak into the bowl. Flappers cost a couple bucks at any hardware store.

2. Test the flapper by pressing down on it with your finger

   If the running stops when you press it down, the flapper needs to be replaced. Unhook the old one from the overflow tube, take it to the store to match the size, and snap the new one on.

3. Check the fill valve and water level

   The water level should sit about 1 inch below the top of the overflow tube. If it's too high, water spills into the tube and the toilet runs endlessly. Adjust the float arm or the screw on top of the fill valve to lower the water level.

4. Inspect the fill tube connection

   The small rubber tube running from the fill valve to the overflow tube should be clipped to the top of the overflow tube, not shoved inside it. If it's inserted too far down, it can create a siphon that keeps the tank draining.

5. Replace the fill valve if adjustments don't work

   Turn off the water supply valve behind the toilet, flush to empty the tank, and swap in a universal fill valve kit. They're under ten dollars and come with instructions.