I wanted to get the board's opinion before I call a plumber. If I can avoid that expense, I will ! Here is my problem : our pipes make a very loud noise, like a humming that gets progressively louder. We hear the noise sometimes several times a day,sometimes in the middle of the night, and it's loud enough to wake me up (altough it doesn't bother my husband). Some days we don't hear it, though. My husband says the noise is caused by a pressure adjustment in the city's pipes, but I'm really worried. Has anyone ever had this problem ? Thanks for all your help !