I got a call tonight from an elderly neighbour we keep an eye on, saying her boiler hadn't come on (and her laptop won't come on either). This is the same one who needed a new CH pump, basic Potterton timer and thermal rad valves sorting that you advised me on previously (and are all now / still working fine). ;-)
I popped over and long-short it looks like there has been some burning on the controller PCB (she said she had heard a small 'bang' earlier but wasn't sure where it had come from).
The fuse had also blown.
So, two questions really. Is there anything running from that board that could start drawing more current than normal that could overload the PCB / relay / tracks like that (and if so what), or is it just one of those things that can happen on those boards please?
If it is just that the board has failed because of bad design (or dry joint / whatever) could someone with a reasonable eye, a soldering iron and some bright, tinned copper wire, repair the PCB and still find the rest of the board functional?
If I can find a replacement controller and she can afford / justify it (over getting a new boiler etc .. 'Warmfront', free / heavily subsidised / ripoff? ... as she is 70+ and registered disabled etc), what are the chances of that one going bang as well?
All I can see hanging off that board is the fan (been replaced twice now I think), the gas control valve, boiler stat and the air pressure switch so I'm not sure if any of those could go low resistance or short (happy to test resistance if anyone can give me a rough idea what they should be please).
All the best and thanks for your time etc.
Cheers, T i m