hissing

Hi, ever since I had a new condesing boiler fiited, whenever I run the hot water tap in my kitchen or bathroom I start to hear hissing coming from a cold water pipe. This pipe runs from the attic, straight down through the floor of the airing cupboard and the noise sounds like it's in the pipe...

Hi, I have an issue with my boiler which consists of it making a hissing noise and pressure meter going up when the central heating is on. I haven't tested what happens when the pressure is extremely high as I turn it off before it goes above 3 bars. The central heating is not working but hot...