Good morning all, I have been having some issues intermitently with my own boiler, if left off sometimes over night the pressure gauge drops just below the .5 bar mark, the boiler then wont fire up. Commence the topping up via filling loop into green zone around 1 bar (cold) and once boiler gets up to working temp it goes into red, over pressurising and dripping out the PRV, if i bleed rads to take pressure down back to around 2 bar (hot) then it’s fine...until its been off then pressure drops on the gauge at least, below .5 bar, this happens most evenings now, but again, as soon as you too it up the pressure is too high unless tou have the radiator temp set really low (40’s) then it maintains for a week or more no probs, as soon as you turn rads up it over pressurises and drips out the PRV again? Faulty pressure gauge perhaps? Or the pressure vessel needs topping up? Any help very much appreciated Oh and no leaks are apparent anywhere I have looked everywhere and most pipes are as good as exposed in my cellar ceiling as its not boarded yet.