I know gas engineers that will, in all dishonesty, claim that multiple parts need fitting when in reality the repair may only require the one part only. We know that car garages do the same; I guess you get good and bad wherever you go. To be honest, it was tempting to charge for the most expensive part that I put in today. In total, I fitted three parts amounting to a handsome parts bill of approximately £200. Charging for those parts would have been wrong.. quite simply because I did not manage to fix the customer’s boiler. I did my level best, consulted tech teams at Baxi (who themselves offered conflicting advice) and eventually, after replacing the spark electrode (the most common fault), the cable (no continuity) and the PCB (spark arching at the PCB instead of at the electrode) I managed to speak to a very knowledgable chap who was able to recognise that the valve hadn’t dropped on the gas valve (just from listening to the sound of the boiler) It was obvious when he said it. If the valve doesn’t drop properly the electrode won’t spark… I checked with a manometer. Indeed the pressure at the inlet valve stayed a constant 18mb. A schoolboy error that cost me £200, 3 visits to the customer’s house and also visits to out of the way merchants and I’m feeling a little stung by own ineptitude. It’s too easy just to lean on tech advice from the manufacturer but we all get a little lazy from time to time.