How To Replace a Toilet Fill Valve

  • 01 of 06

    Replacing a Toilet Fill Valve

    The fill valve is the device that controls the flow of fresh water into the tank of your toilet. It is normally mounted on the left side of the toilet tank, with a tailpiece that extends through the bottom of the tank, where it attaches to a supply tube that runs to a fixture shut-off valve. This part is sometimes known as a ballcock, so named after a design that was once the standard. 

    In most homes, the toilet fill valve opens and closes many time each day each time the toilet flushes, and this constant use means that fill valves eventually wear out and require replacement. If the existing fill valve is an older model with a float ball, now is your chance to replace it with a more modern and dependable fill valve with its own integrated float cup.

    You might also consider using this opportunity to also replace the flush valve assembly. These parts also go bad eventually, and if you want to do a maintenance upgrade, you can buy a kit that includes both the fill valve and flush valve assemblies. Be aware, though, that if you go this route, it will require you to temporarily remove the entire tank. 

    Our project, though, will show you how to replace only the fill valve, a relatively easy job that can be done with the toilet tank in place. 

    Tools and Supplies You Will Need

    Continue to 2 of 6 below.
  • 02 of 06

    Turn Off the Water and Empty the Tank

    Bathroom Renovation - Toilet Valve Problem. Phil King/
    1. Turn off the water to the toilet by turning the handle of the fixture shut-off valve fully to the left until it stops turning. Normally, the fill valve will be located on a water supply pipe coming out of the floor or wall near the bottom left side of the toilet tank, near where the water supply tube connects to the tailpiece on the fill valve. 
    2. Flush the toilet to empty the tank, then remove the cover on the tank and use a sponge to mop up any remaining water in the bottom of the tank. Unless you do this, a small amount of water in the tank could spill out when you loosen the fill valve. 
    Continue to 3 of 6 below.
  • 03 of 06

    Remove the Toilet Fill Valve

    Removing the toilet fill valve. Aaron Stickley
    1. To remove the toilet fill valve, first disconnect the water supply tube attached to the bottom of the fill valve tailpiece, using channel-type pliers or an adjustable wrench.
    2. Next, loosen and remove the mounting nut that holds the bottom flange on the fill valve to the bottom surface of the tank. You may need to reach down into the tank from the top and grip the bottom of the fill valve with another set of pliers to keep in from rotating as you loosen the mounting nut. 
    Continue to 4 of 6 below.
  • 04 of 06

    Prepare the New Fill Valve

    Preparing the new fill valve. Aaron Stickley
    1. Slide the rubber washer included with the kit onto the bottom flange on the fill valve tailpiece. This washer will provide an inner seal that prevents leaking around the base of the fill valve.
    2. Adjust the height of the fill valve, if necessary. Different fill valves have different methods of doing this, but with most, it's a simple matter of screwing the stem piece shorter or longer so the overall length of the fill valve will fit inside your toilet tank. Ideally, the top of the fill valve should be slightly taller than the top of the overflow tube, but not so tall that it will prevent the tank lid from closing.
    Continue to 5 of 6 below.
  • 05 of 06

    Install the New Fill Valve

    Installing the new fill valve. Aaron Stickley
    1. Set the fill valve into the toilet tank, inserting the tailpiece through the opening in the bottom of the tank. Make sure the water outlet nipple is facing the overflow tube.
    2. Holding the fill valve with one hand, use the other hand to thread the hard metal washer, then the mounting nut, onto the tailpiece from below the toilet. Tighten the mounting nut so it is hand-tight. 
    3. Use channel-type pliers to tighten the mounting nut slightly further. Make sure not to twist the body of the fill valve inside the tank.
    4. Reconnect the water supply tube to the fill valve. Once again, you can hand -tighten first and then use pliers to tighten a little more.
    Continue to 6 of 6 below.
  • 06 of 06

    Connect and Make Adjustments to the Fill Valve

    Connecting the new toilet fill valve. Aaron Stickley
    1. Attach one end of the rubber fill tubing to the nipple on the top of the fill valve, then attach the plastic adapter onto the other end and clip it to the top of the overflow tube.
    2. Turn on the water supply valve and watch as the toilet tank refills with water. Adjust the water to a level appropriate for your toilet. The tank should fill to a marked water line on the inner walls of the tank.
    3. Inspect the fittings on the bottom of the tailpiece and shut-off valve to make sure there are no leaks. You may need to tighten them slightly more if there is any seepage.