Adjust the fill valve float to lower the water level

When the tank water level is too high, water constantly spills into the overflow tube and the fill valve never shuts off. Adjusting the float so the valve closes at the correct level stops the running.

Steps

1. Remove the tank lid and flush the toilet. Watch where the water level settles relative to the overflow tube.
2. The water should stop 1/2 to 1 inch below the top of the overflow tube. If it reaches or exceeds the tube, the float is set too high.
3. For a ball float (ball on an arm), turn the adjustment screw on the arm clockwise to lower the ball, or gently bend the arm downward.
4. For a float cup (cylinder riding the valve shaft), pinch the spring clip and slide the float down the shaft about 1/2 inch.
5. Flush again and verify the water stops at the correct level.

Tips

• Mark the ideal water level on the inside of the tank with a pencil for future reference
• If the fill valve hisses or trickles after adjusting, the valve diaphragm may need cleaning or the valve needs replacing