In message , Bob Smith
writes
Anyway, the main question is, do the above sound like there is a problem
with the controller board or the ignition board?

Difficult to say definitely, but it sounds to me more like the sequence
board. It doesn't keep sparking does it ? it could be the HT lead

No, it only sparks after the gas valve goes clunk. Is the sequence board
the ignition board?


Yes (I tend to mix the terms)

It should spark at the same time as the pilot valve opens

You should have a look at your manual, it will show you what is controlled
by which board

Is your ignition pcb a red / black module which fits on the gas valve with
something like S4565TF 2006 written on it ?

It is a green circuit board inside a blue plastic box, with a rubber seal
around the lid. The circuit board has a perpendicular bit on it that fits
over 4 spade connectors on the gas valve.

OK Sit EFD 503 or similar

It has an interconnection diagram on the box - which should show you
what its interface is, from which you should be able to make an educated
guess

--
geoff