The float valve controls the water level in your toilet tank. As water fills the tank, the float rises. When the float reaches a predetermined level, it shuts off the water supply. When your toilet is constantly running or not flushing completely, it is necessary to adjust the float valve. The adjustment depends on whether you have a ball float or a float that rides on the fill valve.
Remove the toilet tank lid and place it on the floor out of your way. Locate the brass adjustment screw below the end of the float ball arm on the top of the fill valve.
Turn the screw counterclockwise with a Phillips-head screwdriver to raise the water level if the toilet is not flushing completely. Turn the screw 1/2-turn at a time. Turn the screw clockwise with the screwdriver to lower the level if the toilet is constantly running.
Flush the toilet and allow the toilet tank to fill. The water should be at the fill line on the back of the toilet tank. Continue making adjustments to the float ball screw as necessary.
Place the toilet tank lid on the toilet once adjustments are complete.
Take the toilet tank lid off the toilet and place it on the floor out of your way.
Locate the level adjustment clip beside the float. The clip is a pinch clip that moves up and down a thin wire.
Pinch the top and bottom of the clip with your fingers. Raise the pinch clip and float to decrease the water level, or lower them to increase the water level. Move the float and pinch clip in 1/2-inch increments.
Flush the toilet and allow the tank to refill. There is a water line on the back of the toilet tank. Continue making adjustments as necessary until the water level is at the water line on the back of the toilet tank.
Place the toilet tank lid on the toilet after all adjustments are complete.
Do not bend the float ball arm to make adjustments. Bending the float ball arm could damage the connection at the top of the fill valve.