Adjust the Float

Lower the tank float so the fill valve shuts off at the correct water level, stopping the overflow that keeps the toilet running.

Steps

1. Remove the tank lid and flush to observe the water level as the tank refills
2. If water rises above the top of the overflow tube, the float is set too high
3. For a ball float on an arm, bend the arm slightly downward or turn the adjustment screw
4. For a float cup on the fill valve shaft, pinch the clip and slide the cup down about half an inch
5. Flush again and verify the water stops roughly 1 inch below the overflow tube

Tips

• This is the single most common cause of a running toilet
• No tools required for most float cup adjustments
• If the water level is correct and the toilet still runs, the problem is likely the flapper or fill valve instead