Hi all, need your expertise to this. My toilet is making a weird honking sound. The sound comes randomly. Sometimes once every minute/few minutes, sometimes loud/soft, sometimes when I on the taps/didn't turn it on. I just did my reno and retained the water tank. Before the reno, there was no such issue. The contractor doesn't have a clue what is wrong. I have uploaded a video to youtube. It is around the 6 - 7 second mark..