My toilet was excessively running, so I replaced the fill and flapper. It caused another problem, so I called a plumber. He replaced the flapper again, and the same on another toilet. My main toilet will have a short fill (2 seconds) every 10 minutes. It is loud, keeps me awake and I am worried about a large water bill. Had the plumber back out and he couldn't fix it. Help!!

You need a better plumber.

Sounds like the flaper valve seat is either eroded or might have a bit a grit or something preventing it from seating correctly. Feel around both with your finger.. they should be smooth and not rough.

There are kits to repair eroded flush valve seats.

Hmmmm, I have a similar problem with an old Kohler with a "canister style" in place of a flapper. (like this http://www.us.kohler.com/us/catalog/partsViewer.jsp?swfFile=/webassets/kpna/catalog/swf/1001330_8_p01.swf&productId=425357&installationId=649884)
I've replaced the rubber seals, not fixed... I've run my finger around the brass where the rubber gasket seats... feels very smooth. I've gone over it (lightly) with a green scrubber pad, still no good. Any ideas on that?

Hi Scotferg

So you are still losing water from the tank to the toilet bowl, huh? If so, and you have replaced all the necessary washers then the only other culprit will be the CURTAIN VALVE WASHER or the screws holding the curtain valve in place.

The only fix for this is to see if a local supplier can order these parts or you replace the entire curtain valve... ;) That, or you buy a new toilet!

Questions? Let me know...

Mark