Toilet flapper fine — dual-flush float can still keep it open
Running toilet
On dual-flush toilets, the half-flush float can interact with a good toilet flapper and leave the toilet keeps running. Check float travel before another flapper swap.
A solid toilet flapper can still leave the toilet keeps running when a dual-flush float hangs and holds the seal open. Check float travel and chain/cable links before you buy another flapper.
Dual-flush float interactions with a good toilet flapper
- Shut off the supply and remove the tank lid. Flush each button once so you see half vs full travel.
- Watch the float and flapper together: the half-flush float should rise and fall freely without catching the flapper edge.
- Adjust float height or cable slack per the tank diagram so the toilet flapper can seat fully after either flush.
- If the float arm is bent or the cable frayed, replace the dual-flush kit rather than stacking another flapper on a stuck float.
If water still trickles after a free float and a seated flapper, stop forcing the handle — check the fill valve next, not a third flapper.
More help
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- Related fixes elsewhere: Toilet keeps running — check the flapper first · Check toilet fill valve float height