The toilet float controls how much water refills your tank after a flush. When the tank empties, the float drops and opens the fill valve; as water rises, the float lifts and signals the valve to slow or stop.

• Two common styles: a round float ball on a rod (older style) or a vertical float cup that rides on the fill valve (newer style).
• Why it matters: A correctly adjusted float helps prevent constant running, overflow into the overflow tube, and weak flushes from too-low water levels.
• Where to find parts: You’ll see universal floats, fill valves, and repair kits available, so you can replace just the faulty piece or refresh the whole tank. Installation steps vary by design, so always follow the included instructions.

1. Shut off the water: Turn the supply valve clockwise and remove the tank lid.
2. Identify your float: Ball-on-rod or float cup on a fill valve.
3. Free the movement: Make sure the float moves without rubbing the tank wall, refill tube, or lid. Wipe away mineral buildup on the arm, shaft, or guides.
4. Check for waterlogging (ball floats): If the ball has water inside or feels heavy, replacing it can help.
5. Adjust the water level: Use the adjustment screw (fill valve) or clip (float cup). For metal arms, a slight bend may help, but go gently.
6. Restore water and test: Turn the valve on and watch a few cycles.

If binding or running continues, replacing the float or the entire fill valve with a universal kit can be a practical next step. Results can vary by toilet design.

• Constant running or hissing: The valve may not be closing because the float isn’t signaling shutoff correctly.
• Water too high or too low: Overflows into the overflow tube or a weak flush from a low waterline can indicate misadjustment or a worn float.
• Waterlogged float ball: A ball that sinks, feels heavy, or has cracks may not float properly.
• Sticking float cup: A cup that binds on the fill valve shaft can stop at the wrong height.

Quick check: Gently lift the float; if the water stops, the valve is responding but the float may need adjustment or replacement. If nothing changes, the fill valve could be the issue. Also peek at the flapper and chain; a worn flapper can mimic float problems. Inspect and proceed with the component that shows the clearest signs.

1. Turn off water and drain: Close the shutoff valve, flush, and sponge out remaining water.
2. For ball-on-rod designs: Unscrew the old float from the rod. Inspect the rod and pivot for corrosion or binding. Thread on the new float until snug (hand-tight), restore water, and adjust water level with the screw on the fill valve or by repositioning the arm.
3. For float-cup designs: The float is part of the fill valve assembly. Some allow the float to be replaced, but many are designed to be swapped as a complete fill valve. A universal, adjustable-height valve can be a convenient option.

Replacements can vary by model, so follow the instructions in the package and avoid overtightening plastic parts. If the tank still runs, the fill valve or flapper may also need attention.

• Match the style: If you have a ball-on-rod, a replacement float ball and rod may be all you need. For newer setups, a universal fill valve with a float cup is often a straightforward upgrade.
• Look for features: Adjustable height, anti-siphon design, and quiet-fill operation can help fit more tanks and reduce noise.
• Consider a kit: If you’re chasing leaks or a running tank, a repair kit that includes a fill valve and a 2" or 3" flapper can address multiple wear points at once. Check your toilet’s flush valve size before buying.
• Materials matter: Corrosion-resistant plastics or metals can be helpful in hard-water areas.

You’ll find individual floats, rods, valves, and complete kits available. Bringing a photo of your tank’s internals can make selecting the right parts easier.