I recently fitted a new ballcock to the cold water feeder tank in the loft since doing this when we turn the hot water tap on we get a vibrating noise. I've been in the loft and the noise seems to be coming from the pipe that feeds the cold feeder tank which then feeds the hot cylinder in the airing cupboard. The system we have in our bungalow is gravity fed.

B .S, October 2013

It could be the ballcock is bouncing up and down when incoming water creates waves on top of the water,try adjusting the screw on the ballcock to alter the water height

toptrish, October 2013

check to see first if the vibration only happens when using a certain tap ie kitchen tap only causes vibration. then it would be that the tap that is causing the noise is need of replacing. if it happens when u use any tap the problem may be the ballcock u changed. replace this item. the noise travels through the water so u may hear it in the walls or loft but it will be associated with one of these problems

kash, October 2013