There is a reason the flapper fix works the first time in a newer Woodbury build and fails three times in a 1970s Stillwater ranch. It comes down to water and age.
Much of the east metro and St. Croix Valley runs on hard water, and Stillwater and the surrounding communities that pull from wells or blended sources see real mineral content. Over years, that hardness leaves scale on the flush-valve seat, the exact ring your flapper has to seal against. A brand-new flapper pressed against a pitted, scaled seat still leaks, because the sealing surface itself is ruined. That is why a homeowner can go through three flappers in a month and never fix it.
If you are on your third flapper and it is still running, stop buying flappers. The part is not the problem anymore, the seat it seals against is, and that needs a real diagnosis.
Older homes add a second trap: the shutoff valve under the toilet. In pre-1990 east metro houses those stop valves are often original, and when you finally close one to swap a part, it either will not fully shut off or it starts weeping at the packing nut afterward. Now a simple job needs a valve replacement to finish safely. This is exactly the kind of thing we carry the parts for and handle in one visit.
Get an instant number on a common toilet repair, or
book toilet repair online when you are ready.