I wonder if any one could give me some advice? I am getting a humming noise from the water pipes which seems to be associated with using cold water. The vibration seems worse on a cold pipe which leads/comes from the loft. It happens when the dish washer, washing machine, shower etc is used and lasts for around 15 seconds. Having looked at most of the postings here, am I correct in thinking a change of float valve in the water tank would be the first move?