Sewage water drain noise

I have a house that when you fiush the upstairs toilet, you really
hear the sound of the water draining …when your downstairs. The
homeowner doesnt like it. Anybody know why the noise is excessive ?


Hard water? :mrgreen:

If it is a loud humming sound, it is a fill valve on the toilet.

Plastic waste pumbing is much louder than cast iron. Insulating the waste lines should help if it is accessible.