I replaced flapper because toilet ran constantly with a small leak. It worked beautifully for a couple of months, but now the flapper sticks in the up position so it is running again for a different reason. Please help!
:confused:

Try giving the chain a bit more length so the flapper isn't pulled as far when you flush.

I replaced flapper because toilet ran constantly with a small leak. It worked beautifully for a couple of months, but now the flapper sticks in the up position so it is running again for a different reason. Please help!
:confused:
Sounds like your flapper linkage needs adjusting.
With the flapper seated the linkage wants to have 1/4" of play. Too much play and the flapper doesn't get pulled back enough giving you a short flush. Too tight and it lets water seep past the flapper. I adjust the chain by the link and if it needs fine tuning, I bend the flush lever rod a bit untill I have the desired play in the linkage. One more thing about a flapper. you will see where the old flapper hooks onto the base of the white overflow tube. On a older type with no hooks the flapper has a ring that slips down over the overflow tube to the seat. If your tank has hooks, take a sharp knife or scissors and cut the neoprene ring off on the marks provided and hook the flapper on the hooks. Leaving the ring on will interfere with the flush. The water level in your tank should be 3/8 to 1/2" below the top of the overflow tube when the tank's filled Good luck, Tom