My combi boiler keeps losing pressure. On sunday it dropped to zero, but prior to that it kept dropping despite topping up to 1 bar with the filling loop, and then when heating was on it went right up to 2.5 or even 3 bar. So on sunday engineer came out and said expansion tank had no air in it, and pumped it up so gauge showed 1 bar, then heating went on, pressure rose to 1.5-2 bar ish and it was fine, engineer went on his way.
Then last night the pressure starting dropping again, got up this morning and it was on zero again - argh!!!!!!!!!!!!!!!!!!
Engineer coming out again tomorrow, but it is showing the same symptom ie top it up and then put heating on = high pressure (he said yesterday that expansuion tank won't work with no air in it hence high pressure on gauge).
So, what causes the expansion tank to lose the air? I'm really worried it is gonna need parts and with Christmas round the corner and a house full of guests I'm getting more than a bit worried.
Also, what would happen if the heating came on when pressure gauge showed zero?
Then last night the pressure starting dropping again, got up this morning and it was on zero again - argh!!!!!!!!!!!!!!!!!!
Engineer coming out again tomorrow, but it is showing the same symptom ie top it up and then put heating on = high pressure (he said yesterday that expansuion tank won't work with no air in it hence high pressure on gauge).
So, what causes the expansion tank to lose the air? I'm really worried it is gonna need parts and with Christmas round the corner and a house full of guests I'm getting more than a bit worried.
Also, what would happen if the heating came on when pressure gauge showed zero?