Update: Boiler has been off now since Friday - yesterday, I checked the pressure and it was back at zero.
But did find after pressuring it to 1bar there is a small water leak (no more than a few drops - 5mil) of water coming from the boiler itself when I switched it on. It appears to drip down...
Only further info - have tried numerous times today to get boiler to work.
Trying HW only causes lockout as the pilot light does not come on.
Trying CH only (full) runs for 5-10mins, heat in rads but pressure climbs to over 2.5 bar, locks out. Adjusting the temp at all during this causes...
I have a ravenheat CSI 85 (T) 780 series combi boiler. Its the bane of my existence!
Came home yesterday to find boiler locked out. Normally, resetting our boiler is pretty simple - switch everything off, ensure pressure is between 1 - 1.5bar (usually requires a top up of pressure or a drain...