My toilet will make a noise like it is filling up when nobody has used it for hours or the middle of the night. The flapper looks okay, but is this the only thing in there that could be doing this?

Hi Silk and welcome, it's probably the flapper leaking, cheap to buy and not that hard to change, also make sure the chain has the proper tension. Good luck and let us know how it goes.

Hi Silktassel and Welcome to The Plumbing Page. At AskMeHelpDesk.com.
The problem is caused by the ballcock trying to fill while water is seeping out of the tank. The sound you hear is the washer vibrating against the seat of the ballcock. First check there linkage between the flapper and the flush lever. It should have 1/4" of play when your tank is filled. Next feel the flat side of your flapper. Does it have wavey edges? Do your hands come away black? Replace it if it does. And last check the seat itself. Any nicks or rough spots? If so click on back. There are replacement seats that glue right over the old one and are easy to replace. One of the above should take care of your howling. This happened in a new house some years ago. Only at night and in the early morning. They thought the house was haunted and werthank you for rating my reply.e about to move out. I caught it in the powder room toilet. It would vibrate and the pipes in the wall would pick it up and carry it all over the house. Hope this helps