Toilet still running. Replaced flapper.
When you say you're toilet is running, I'm assuming you mean that it continues to fill. There's two explanations for that.
It's leaking from the flapper. The water level in the tank drops and the fill valve eventually opens, filling the tank. Despite being advertised as "universal" not all flappers are the same. You might want to try an OEM replacement. Some of the flappers also have a little foam float on the chain. If that's set too high it can pull up the flapper slightly, causing a leak. Move it closer to the flapper and inch or so at a time. It's also possible that the seal where the flapper seats has deteriorated over time. You can replace the overflow tube or Korky makes a little kit to fix it.
The fill valve leaks, causing water to flow continuously. The way to tell is to look at the level of the water in relation to the overflow tube. If the water level is at the top of the overflow tube, it points to the fill valve. You can double check by shutting of the water supply valve and noting the level in the tank. Give it an hour. If the level has stayed the same, the flapper is sealing and replace the fill valve. If it has fallen, replace the flapper.
Remember when I said that not all "universal" flappers are universal. It seems that the 501 is designed for "older" toilets, specifically 3.5 gallon flush toilets made before 1994. That's not to say it won't work.
But before we worry about replacing the flapper, let's figure out where it's leaking from. If you happen to get this message tonight, turn off the water supply to the toilet and note the water level in the tank. Then check in the morning.
We'll take it from there.
Think I clicked and responded and chose the solution all in some kind of reverse order?? Uh......If you did not receive my Thanks....then Thanks! Although I do not know what the actual solution is yet? Tomorrow-27th.
Thank-you for responding!
Thank you for responding! Let you know where I am: 11pm here & I just checked my mail and got your response so I'll be doing this tomorrow.
The Flapper is identical to the previous but obviously bigger since the older Flap' shrunk so much. Little experience; didn't know you were supposed to try replace annually. That's what HD rep said. American Standard/ 6.0 Lpf/ 1.6gpf.
Replaced with identical Fluidmaster 501 Flapper. As you said the "overflow valve" just continues to fill!!! I will do the level check tomorrow as well as check condition of the seal.
Also, very similar to what you mentioned, when I replaced the Flap' and then turned the water back on it appeared to me the chain was too long. When I flushed the chain was so long it did not lift up the Flap'. I tied a knot in it. It worked a few times then went back to running? May have made the chain too short with the knot?? I don't know? From your message I have 3 options to check? I get obsessive with directions when it's not in person, I mean no offense what so ever. As I said I have not done a lot of work with plumbing but I have the time and always wanting to learn more about repairing any/everything in the house. Helps financially as well; rambling..Thanks again!!!
The solution is going to be found at the flapper/drain area...
Check all this: