Boiler stopped heating yesterday, no radiators or hot water. Chugging noise. I texted gas engineer who said likely to be frozen compressor pipe, - it has been -7 overnight last few nights and not above zero in daytime - to look for external white pipes to outside drain and warm it, not with boiling water. The youtube videos I watched were of substantial white pipes, where the thing I think I have is a small copper pipe way up in wall venting into air (as boiler is in loft). Created ice rink with my overenthusiastic warming various pipes. Thought I'd defrosted copper pipe too, but did also get water into it (which might be the problem). Still not working.
In meantime I've been several times into loft (which scares me). Have tried repressuring boiler and resetting it. (which surprisingly is at 0 as it was serviced fairly recently) but while I can hear the rush of water when I turn knob, the pressure gauge doesn't move at all. I'm moving the second white key as far to the right as it will go, which admittedly isn't as far as I remember before. Could this be frozen? Or would the impact of a still frozen pipe elsewhere bring the pressure to zero?
Noticed another massive white pipe out of the boiler, which also is cold, wondering if this is what I'm meant to be gently heating too? As you can tell after a day in the cold, with gas engineers rushed off their feet and not picking up, I'm getting in a tizzy.
Final query, as its now pretty cold in the house, I'm keen for water pipes not to freeze if possible. Have one cold tap on as minimal a flow as possible through night, is this likely to make any difference, or what else might I do?
My get up and go has gone after a day motivating myself onto that scary wobbly loft ladder and working in the cold. Any suggestions very welcome, though I think I'm going to be very persistent with the gas engineers tomorrow.