your flapper is leaking water into the bowl. once the tank gets low enough, the valve opens and refills it. then the process starts over again. turn off the shut off valve, add some food coloring tot eh water in teh tank. wait an hour, if the bowl water starts to turn colors, then the flapper is bad or getting a bad seal.

if you use those toilet cleaner "mints" that go in the tank, remove them and toss them in teh garbage. they are bad about causing flapper issues.

He's right.

Several flapper options in the stores. I like the "Bull's eye" flapper.

davidandkasie... I wish you had not told them about those hockey puck bowl cleaners. Those things make me a lot of money. Not only do I get simple service calls to replace flappers that went bad prematurely, I charge an extra $35 when I find the blue ones in the tank. That charge is my compensation for having that blue die on my hands for the next three or four days...LOL.

yep, a friend called out a plumber on Saturday cause her toilet would not stop running. turned out to be the cleaner disc had broken a chunk off and held the flapper open partially. she paid 100.00 for the guy to pull the disc out and toss it in teh garbage. then she got mad at ME cause i never told her about this.

Thanks everyone. I think the flapper might not be seated properly (is that the term?). It now seems to have healed itself. We don't use those toilet bowl cleaner things. But we've been having a major issue with grit from the well. I think some grit in the toilet bowl (they need to be shopvaced out) might be the culprit. Thanks again.

I had the same problem, but it wasnt the flapper. It was the plastic refil tube. It had a crack.

mine was a string that was inside (was a new toilet). The string was stopping the flapper from closing properly...thanks to all of you for the ideas so I knew where to look :)