Is a pressure drop on my new combi boiler due to a leak? It will go from the high end on the pressure gauge green section to the low end in about a week/week and a half. I have a fancy heated towel rail that, through it's design. can never be totally air free and is a nightmare to bleed even with two auto bleed valves. Can this be the culprit? or is it, as I suspect, always a leak? No sign of water anywhere so it must very small.
TIA
Jb