18-12-2016, 11:33 PM
Obviously it makes sense to try "cheapest-first", and electrodes can and do wear. But I wanted to provide some facts about how it all works, in the hope of saving confusion about resistance readings.
It seems likely the gas valve is OK from what you say, but I can't comment further. I hope it is - that is what finally wrote off my old boiler (was glad to see the back of it though!).
But it could be the PCB - there are many "functional blocks" on there... The control logic is deciding to shut off the gas because it hasn't received a "flame good" signal, which relies on the electrode (and wiring) being clean and in good condition, plus the electronics dedicated to sensing the ionisation current (usually just a couple of transistors and associated components IME) correctly doing its thing.
But most likely the electrode... Fingers crossed!
It seems likely the gas valve is OK from what you say, but I can't comment further. I hope it is - that is what finally wrote off my old boiler (was glad to see the back of it though!).
But it could be the PCB - there are many "functional blocks" on there... The control logic is deciding to shut off the gas because it hasn't received a "flame good" signal, which relies on the electrode (and wiring) being clean and in good condition, plus the electronics dedicated to sensing the ionisation current (usually just a couple of transistors and associated components IME) correctly doing its thing.
But most likely the electrode... Fingers crossed!
