Why does my toilet squeal?

Recently, because of a cracked stack pipe, the toilet pipe was changed from a 4" pipe to the more modern 3" standard pipe. (The house is historic.). Since this change, my toilet now thumps when you flush it and squeals a high pitch for about 60 seconds or so. I'm told the thumping is normal after this type of work. Not so sure on either. Any idea what could be causing these noises?

  2 answers
  • Benwa Benwa on Sep 18, 2017

    Close the supply valve a little , the water pressure is too high. The thumping is coming when the water shuts off in the toilet. Water hammer.

    Might think about installing a PRV pressure reducing valve at your water source.


    Just an old retired plumber/ pipe-fitter thinking out loud.

  • Maxie Maxie on Sep 18, 2017

    .ound like they (the plumbers) changed the ballcock to a fast closing valve, You need a shock stop now installed change back to change back to ballcock with a float ball slow closing.