loud noise from hot shower
After a complete bathroom renovation in a condo:
When turning the shower all the way on hot, there's a very loud noise with vibration in the wall. Sounds like it's right behind the shower head. One person said like a lawn mower, the other like a helicopter in the wall.
It doesn't happen with cold water with the shower nor with hot or cold from the tub.
The shower head is firmly attached, doesn't move.
Diverter is from Moen and now single handle (before two handles) to mix.
Plumber fumbled around for two hours, adjusting the hot water scalding prevention thingie (so now you can't crank up the hot as much anymore).
The sound now only comes every now and then.
So, when the next plumber showed up, it didn't make the noise. He claimed that the valve in the diverter was loose and air could come in.
Someone else's theory is that it's related to the high water pressure and can be easily fixed by removing the water saving from the (new) shower head.
Someone else suggested opening up the wall because the pipes are hitting the stud (for what it's worth, the only pipe is the one from the diverter up to the shower head; no additional pipes).