Toilet flapper — tighten the handle nut for partial lift

If a toilet keeps running even after a new toilet flapper seats well, look at the trip handle. A loose handle nut inside the tank can leave the flapper partially lifted so the tank never quite stops filling.

Tighten the toilet handle nut that causes a partial flapper lift

1. Remove the tank lid. Flush once and watch: if the flapper never fully drops, or the chain stays slightly taut with the handle at rest, check the handle.
2. Inside the tank, find the plastic or metal nut on the handle shaft. Snug it so the handle returns freely without binding — hand-tight plus a slight turn, not wrench-crush that cracks porcelain.
3. Set chain slack so there is a little play when the flapper is closed (about ½ inch is common) — a tight chain mimics a loose handle lift.
4. Refill and listen for a quiet stop. If the tank still refills on its own with a seated flapper and correct chain, check the fill-valve float next.

Honest stop: do not overtighten tank bolts or the handle nut. Cracked tanks are a replace-the-toilet problem, not a flapper tweak.

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