A leaking fill valve allows too much water to seep into the tank. Eventually, the excess water pours into the overflow pipe, causing a costly problem. There are few repair options for leaking fill valves, so replacement is usually the best solution. Filler valves come in three styles, and installation is the same for all. Older toilets usually have a ball valve mechanism with a metal arm and a large float. An alternative valve has a smaller, cup-shaped float that moves up and down in the fill pipe. The other type is pressure sensitive, almost flat, and is installed near the bottom of the tank. You have a choice of which type of fill valve to install.
Turn the water supply valve clockwise to shut off the water supply to the toilet. Install the valve directly under the bottom of the tank.
Push down on the flush lever and hold it down while the tank empties. Holding the lever down will keep the drain valve open, allowing as much water as possible to drain from the tank.
Sponge the remaining water out of the tank and wring out the excess into a bucket or nearby sink. To remove the water more quickly, use a wet/dry vacuum to suck up the remaining water.
Loosen the nut on the bottom of the tank where the water supply line enters. This nut is a coupling that connects the supply line to the fill valve.
Remove the old filler valve by pulling it up and out of the tank. If you are replacing the old unit with a cup-shaped fill valve, measure the height of the overflow tube with a tape measure. The pipe is in the center of the tank, and the flapper valve is attached to it. Unscrew the tower of the cup-shaped filling valve until it is about 2.5 cm higher than the overflow pipe.
Insert the replacement part for the filling valve into the opening at the bottom of the toilet tank. Secure the fill valve and water line by tightening the nut – a new nut and washer are usually part of the new fill valve kit. Hand tighten the nut and then turn it about 1/4 turn with the adjustable wrench. Over tightening may damage the porcelain toilet.
The pipe has a small slot that holds the line in place.
Reconnect the water supply line, turn the water supply valve counterclockwise, and allow the toilet tank to fill with water.
Adjust the water level in the tank. The method you use for this adjustment depends on the type of fill valve you replaced. For ball valves, adjust the metal float arm by screwing it on or off where it attaches to the fill valve. This will shorten or lengthen the rod so that the float sits higher or lower. For floats with buckets, use a spring clamp to position the float on the tower. Pressure sensitive fill valves have a small knob that you turn left or right to adjust the water level. The maximum water level should be about 2.5 cm below the top of the overflow tube.