Turn off the toilet's water supply valve located behind the toilet by rotating it clockwise.
Remove the tank lid carefully and place it on a flat, safe surface to avoid breakage.
Flush the toilet to drain most of the water from the tank.
Use a sponge to soak up any remaining water in the tank for a dry workspace.
Inspect the rubber flapper at the bottom of the tank for warping, cracks, or buildup.
If the flapper is damaged or worn, unhook it from the pegs and replace it with a new one.
Check the chain connecting the flapper to the flush handle; adjust it to have slight slack.
Inspect the float height and adjust it so the water stops about an inch below the overflow tube.
If the fill valve is noisy or doesn’t shut off, consider replacing it with a new one.
Use an adjustable wrench to remove the old fill valve and install the new one per instructions.
Reconnect the water supply line to the new fill valve and tighten securely.
Turn the water supply valve back on slowly and let the tank fill.
Watch the tank fill and ensure the water stops at the correct level.
Flush the toilet and observe if the flapper seals properly after the flush.
Listen for any continuous water flow indicating the issue persists.
Make final adjustments to the float or chain if necessary.
Ensure all parts are secure and functioning correctly.
Replace the tank lid carefully once the toilet is working properly.
