Our pipes make a loud roaring noise when the toilet tank is flushing and re-filling. Our apartment had been empty for a few months when we moved in and initially the noise happened when running the hot tap. After a while this cleared up but then some people moved in upstairs after that apartment had also been empty for a few months. It started again but this time whilst flushing and re-filling.
It is the same noise (sounds a bit like a go-kart engine) so I can't see how it could be un-related but cistern noise solutions don't sound like they would work for this since it was originally related to the boiler.
It seems to be getting worse the more we use the toilet - if anyone has any ideas it would be much appreciated.
Thanks.