Hi, I'm housesitting for a friend for a while and have a problem with their water system. After running any of the Hot taps for a while the pipes in the bathroom start to hum really loudly. The only way to stop it is to turn on the bathroom sink tap for a few seconds. Is this some kind of problem with the pressure? It hasn't always done this but not sure when it started exactly.... Driving me mad as cannot run a bath!!
All help appreciated