How to Adjust a Toilet Fill Valve

A toilet in a private bathroom flushing.
What You'll Need

While toilets are built to regulate the amount of water that they use, it is still sometimes necessary to adjust your toilet fill valve. Whether you are trying to conserve water by reducing the amount you use with each flush, or trying to fix a toilet that does not flush with enough strength to work properly, adjusting the fill valve is something that requires some careful effort. However, there is no reason that you cannot adjust your own without professional help, as it requires no special tools or skills. What follows should give you everything you need to know about how to make this adjustment.

Step 1 - Find the Fill Valve

Before you can do anything, you will need to locate the fill valve in your toilet tank. First, set up a towel flat on the floor. Then, remove the top of the tank to open it up, and lay it down on your towel. You should see a mechanism with a device that floats at the surface of the water somewhere inside. This device can vary between models and appear very different. For example, sometimes there will be a device that floats attached to a metal arm. In other models, the floating device is a cylinder that surrounds a pipe. Either way, the purpose is the same—to detect when enough water has entered your toilet tank and stop the flow. Thus, to change the amount of water used in a flush, your goal is to adjust the mechanism that the floating device is attached to.

Step 2 - Adjust the Height

To adjust your toilet's fill valve, you will first have to decide which direction to adjust it in. No matter what sort of model your toilet is, adjusting the floating device to sit higher will allow your toilet to put more water in the tank before shutting off, so you should do this if you want to increase the water flow when you flush. If, on the other hand, you want to reduce water use, you should adjust the floating device to be lower, so that less water is allowed inside before this valve shuts off the flow.

The specifics are slightly more varied between the different types of toilet fill valves. If your toilet has an arm mechanism that rotates, you should be able to adjust a screw at the point of rotation to adjust the height of the floater. In extreme cases, if the fill valve is damaged or inaccessible, you might be able raise or lower the floater by simply bending the metal arm, in the case that you don’t wish to replace it. On the other hand, if your toilet has a cylindrical floater that surrounds a pipe, there should be a spring that you can press to release the floater so that you can adjust it up or down. Once you have adjusted it, tighten the screw or re-engage the spring device.

Step 3 - Finishing Up

Make sure everything is secure and as it should be before giving your toilet a test flush. It should work as planned, but you may need to adjust further to have the perfect amount of water in each flush.