I had a bathroom renovation including totally new toilet (using the existing plumbing) with new cistern, pan, etc.
After installation, but not immediately, I started having this vibrating / grinding sound in the pipe after flushing, it happens just as it starts to fill up. When I open the lid, the part with the ball cock seems to visibly vibrate a bit when it makes the noise.
The sound lasts about 3-4 seconds and cistern fills normally so I don't think it's a problem as such but it is quite annoying!
It has only been installed for about a month so not long enough for scale to build up I assume.
I'm curious what could cause this (and if I can investigate/fix it myself without calling the installer back for something as minor as that) especially since it didn't start happening immediately after the installation?
I haven't changed anything else in the plumbing since it was installed.