Hello,
We have a townhouse that we've lived in for about 1 and 1/2 years. Over the past few weeks, there's been a very loud vibration coming from the wall that supplies water for both the upstairs bathroom and the downstairs bathroom. You can actually feel the shower head vibrating. It's extremely loud and will fade in and out. It is random, and will occur when no water has been used. It seems to be increasing daily and happening during the day, and in the middle of the night. When it occurred the other day for a long period, we went to the basement to see if we could isolate a pipe. When we grabbed the hot water pipe in the basement, you could also feel the vibration in your hand. What could be causing this, especially when no one is using any water and nothing is running (hot water tank, water softener, etc.) This is driving us nuts! It's soulds like the whole house is vibrating. Thanks!

Sounds like water passing over a worn rubber washer.

I'm guessing it's likely a worn out flapper valve in a toilet that is causing a toilet to refill periodically past a worn out angle stop or gate valve.

In most areas of Florida, there is constant water pressure of about 60 pounds, when I moved to atlanta 6 years ago I discovered what a prv was. It is a pressure reducing valve. The average pressure in the atlanta metro area is 146 psi. by code it must be under 85 psi. however, of the calls I have serviced with your symptoms I have by far found a toilet that was leaking through a bad flapper or a flapper chain too tight or the small tube going into the overflow was too far down the overflow and causing the tank to syphon out. Next time this happens go take the lid off each toilet and see which one is refilling at the high water level. The float is vibrating on the water and it is refilling as fast as it is draining and stuck on 'almost full'. The washer at the top of the fill valve is fluttering. I usually simply replace it with a fluidmaster 400 and maybe replace the flapper and make sure I have no syphonage.

Hello,
We have a townhouse that we've lived in for about 1 and 1/2 years. Over the past few weeks, there's been a very loud vibration coming from the wall that supplies water for both the upstairs bathroom and the downstairs bathroom. You can actually feel the shower head vibrating. It's extremely loud and will fade in and out. It is random, and will occur when no water has been used. It seems to be increasing daily and happening during the day, and in the middle of the night. When it occured the other day for a long period, we went to the basement to see if we could isolate a pipe. When we grabbed the hot water pipe in the basement, you could also feel the vibration in your hand. What could be causing this, especially when no one is using any water and nothing is running (hot water tank, water softener, etc.) This is driving us nuts! It's soulds like the whole house is vibrating. Thanks!
Check the hot water heater ,possible hot water heater pressure release valve get a plumber,for safety reasons

Excellent solution!

When we grabbed the hot water pipe in the basement, you could also feel the vibration in your hand. What could be causing this
Could this be a faulty heat trap nipple on the hot water inlet? Regards, Tom