I know this doesnt relate to your problem but in case anyone else is struggling over their baxi combi boiler as i have done since yesteday here is my solution: my boiler wouldnt light; it was sparking but there was no gas coming through. The pcb was not sending electricity to the gas valve to open it and the manual said replace pcb which are about £80 cheapest i could find anyway. I asked my local tv repair guy if he'd look at the board but he said he couldnt do them. I toyed with the idea of replacing all the components but there were to many. So for the second time i look closley at the solder on the back of the board and found one scorched terminal which was loose (I think they call it a dry joint) I thought I'd try and resolder it first before replacing the component. I reinstalled the pcb and fired up the boiler successfully! saved £80 thank you. good luck
originxxx, November 2004