How to Adjust a Toilet Float

If the toilet is running and won't stop, the issue may lie with a float valve that is set too high. You can incur an impressive water bill if you don't take care of this problem. Conversely, if the water level is too low, you won't get enough flushing power, and you'll need to fix the float. The good news is that anybody can learn how to adjust a toilet float. Before we get to the troubleshooting, we need to start with the basics.

What Is a Toilet Float Valve?

The float is the component within the toilet tank that actuates the fill valve. You're looking for either a float cup (cylinder) or a ball and arm float. When you flush the toilet, the float lowers, opening the fill valve, and then closes it when the water level reaches the set height.

How to Adjust a Ball and Arm Float

The ball should be easy to identify, and it's connected to the fill valve with a long metal rod (the arm). Where the rod connects to the valve, locate the adjustment screw. Turning this screw will change the water level. The sweet spot should be 1 - 2 inches beneath the top of the overflow tube.

While adjusting, it's helpful to empty the tank. You can probably make the adjustment in the time it takes to flush and fill, but if not, cut off the water supply, then flush, then adjust.

How to Adjust a Float Cup

The float cup is a cylinder-shaped component of the fill valve assembly. To adjust it, you first need to locate the adjustment stem. It usually runs vertically, parallel to the main part of the valve. You do see some models where it's suspended horizontally at the top of the assembly, but that's not as common.

The adjustment stem contains a screw (probably at the top) that can be turned to adjust the water level. Clockwise turning lowers the water level.

It's possible you have a slightly different configuration, and these instructions won't exactly apply, but that's the exception to the rule, and if you look at it long enough, you may figure it out. If not, it's best to try to find a manual for the specific make and model you're working on.

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