How to Fix the Auto Fill on a Swimming Pool

While typically long-lived, an auto-fill valve that is part of the automatic water filler on most in-ground residential and commercial swimming pools is a common part that requires replacement. Replacement is not difficult, and the part's operation is easy to understand. The valve in an auto-leveler operates on the same principle as a toilet valve--when water in the tank is lowered, a float drops and opens a valve which permits water to return to the tank (pool) until filled. Just as with toilets, they wear out, and there are two basic designs: horizontal- and vertical-float valves.


Removal and Replacement

Step 1

Locate the automatic water filler to determine which valve style is required. The filler will be positioned near the edge of the pool and has a 7- to 10-inch lid, depending on the design. Older pools typically have the horizontal float system. A brass valve is located on the side of the filler bucket and a 3- to 6-inch brass arm extends to the float. Newer systems use the smaller-diameter bucket and have a vertical Fluidmaster-style float with a sliding float and the valve positioned at the top.

Step 2

Turn off the water at the water source. Ordinarily, the water supply valve is located in the area in a direct line that extends from the filler bucket to a nearby structure--such as along the foundation on the side of a home. But some are placed inline in an enclosed box at ground-level.

Step 3

Remove the defective auto-fill valve/float assembly. For the side-mount brass valves, a wrench is required to unscrew it from the filler bucket. For vertical valve and float assemblies, a wrench may not be needed. Reach down on each side of the vertical filler tube, grasp firmly with both hands and unscrew in a counterclockwise direction.

Step 4

Turn the water supply on for a minute to flush the supply line of debris. Wrap the threads of the new valve with a small amount of Teflon thread tape and replace in the reverse process as removal. Do not use liquid sealers on the vertical valve and do not overtighten either valve.

Step 5

Screw in the brass valve so that the outlet of the valve is oriented down to the bottom of the filler pot. Screw in the Fluidmaster-style vertical valves so that the float and valve arm are oriented toward the center of the filler bucket and do not interfere with the side.

Step 6

Turn the water source back on, depress the float to ensure water fills the bucket and adjust according to the valve installation instructions.

Moss Strohem

Moss Strohem has a background in business and finance, and an avid interest in youth sports, health, nutrition and physiology. He writes both technical information and market commentary as a private consultant and has researched and authored business plans.