Anthony Curren
First if pressure gauge on boiler does not drop then leak is on cold or hot water systems. If you turn off water supply and drain then any leak or noise is from boiler heating circuit. If you have water tank turn off hot water at tank if leak stops fault is hot water pipes. If you have combi boiler then turn of water supply to combi if leak stops leak is on hot water feed from boiler to taps. If none of the above stops leak leak is on cold water supply.
