Sounds like there is a dying cow in my plumbing

[bernadette71]

I am stumped. When I turn the water on in my tub or the washer runs, after a minute or so there is a med to loud humming coming from my water heater or in the wall behind it (seems louder in the wall behind it). I had a plumber apprentice come out and he said it was water hammer, I didn't think so. He replaced the vales on washer and the guts in one toilet, It is still happening. Any suggestions. He says he's stumped. It seems to do it when hot water is being used.

 

[plumbitright]

If you have a check valve in your systems sometimes they can flutter causing a humming like sound. Depending on the type of hot water heater there is sometimes a check valve right in the cold water dip tube (the tube that directs the cold water to the bottom of the tank,) that could be also causing the humming sound.