In message snipped-for-privacy@news.diybanter.com, Jonathan Stuart
> snipped-for-privacy@news.diybanter.com writes-
>
> Before replacing the PCB, can I check the following thoughts with you: >
> How is the pilot light detected? A possibility is that the pilot flame
> changes the spark potential/resistance, which is detected
> electronically.-
>
> The pilot is detected on the pcb. The flame can be thought of as > lossy
> diode between the spark electrode and earth and is sensed down the HT > lead. > - >
> If the pilot is weak/borderline, could this be the cause of the
> problem?-
>
> Yes, if the main boiler coming on is blowing the pilot flame away from > the electrode
> -
>
> How do I adjust the pilot light on the gas valve to increase flame > size? >
> How do I get to the pilot nozzle to inspect/clean it?-
>
>
> There are others here much better qualified to answer that than me > > -- > geoff
Problem solved. Pilot injector nozzle is housed in burner pilo assembly. This was fouled with soot. Removed and cleaned with water an matchstick. Cleaned two v.small holes with v.fine fuse wire. Reassemble and fired up a treat. Toastie
-- Jonathan Stuart