Where about on the circuit board does the spark electrode lead attach, as m?

Where it plugs in will be determined by the length of the lead, the connector on the end of the lead, and the socket connector on the printed circuit board.

The manufacturer / designer will be unlikey to have created multiple places for it to be incorrectly connected i.e. it should ideally be self-evident where it fits. It should also ideally, be impossible to get it wrong without a lot of effort. After all - these things are supposed to be simple enough for heating engineers to fit.

Good luck with the manual...

Peccavi
December 2009

http://www.glow-worm.co.uk/products/pdf/discontinued/boilers/Ultimate60FF.pdf

if you go there you can down load a manual

b
December 2009