I replaced the outside tap the other day and since then I get an "drone" noise occuring intermitently when I turn the taps on. It seems to be coming from the pipework under the sink - when I hold the mixer head at the kitchen sink I can feel a vibration and the noise decreases. It only does it for about 5-10 seconds and then goes away again.
Anybody got a clue about what it could be?
Thanks!