When the shower is on, I can hear a strange noise coming from the pipes. At first I thought it was moaning from a cat outside or maybe some kids but it turns out it''s from the house. The noise sounds like a dull, low moaning. When I turned off the cold water, the noise was still clear. When I turned off the hot water, the noise stopped.
Please help. I hope it's nothing as I'm not prepared to endure the expense!

Thanks

What brand is your shower valve? One handled or two knobs? How old? You have something that's vibrating in the valve but until I know what you have I can't be of much help. Answer me and I'll answer you. Cheers, Tom

I have no idea how old the valve is. There is one toilet valve. The plumbing for the shower is hidden behind tile. It was like that when I bought the house. The house was built in 1886 so it's pretty old. The pipes were probably done in the 70's.
Thanks!

What brand is your shower valve? One handled or two knobs? The brand name is usually found on the knob or handle insert. Let me know. Cheers, Tom