I had a reoccurring issue over the past years with my house making a strange screeching noise every time someone flushes the toilet. I've brought in 4 different plumbers to diagnose the issue in the past and both of them failed to do so. The moment Jon arrive, he knew exactly what was wrong within 10mins. He told me I had a broken water main intake valve. (Which explains why my water main in the house has bursted multiple times in the past years!!) Jon replaced it and saved all my household water pipes from exploding!! I couldn't be more thankful for such a professional and well certified plumber!