Ian, I couldn't agree more, unfortunately finding a competent engineer isn't always easy. Just out of curiosity why does the flame sensor need a good earth?
Just a 4mm wire between the neutral and earth bus bars plus a belt and braces wire from the earth bus to the ground spike. I'll get some more wire and put in common earth's on all the major items this evening. Sorry no picture.
Well it turns out Ian was very nearly right; I bought one of those socket checking plugs and tried it in the boilers socket, sure enough it went beep beep but not for reversed polarity but for an earth error, to cut a long story short the earth wasn't bonded to the neutral so was floating...
There has been some electrical work done so reverse polarity is defiantly a possible. While it briefly runs it does give heat to rads or water, he's checked the gas pressure and that the boiler is setup for LPG. He's "not a fan" of Vokera which is whilst I was a bit dubious about the PCB - that...
I'll mention that but he did run a series of electrical checks - is it the sort of thing where you can just try reversing the polarity and trying or will that fry the pcb or for that mater if that is the problem is the PCB already fried?
I have a Vokera easy heat 25Ci LPG that alarms out after a minute or so, engineer has investigated and decided the flame sensor was at fault so fitted a new one but the fault remains. In the minute or so the boiler is on it repeatedly fires up then stops before eventually faulting out after...