pott.profile 30e pilot problems

mypotterton profile 30e is playing up.its a system boiler, the stat is on, programmer on, fan kicks in, but there is no spark in the pilot electrode. Should this boiler have a permanant pilot or just one should click on when the boiler is started up? Any ideas what i need to replace?

Pilot is lit on demand.

Undo the screw which drops the metalwork withthe pbc and fan switch on it. Identify the micrpswitch on the air pressure switch.
Using a neon screwdriver, seeif the orange wire connection on the microswitch goes live a little after the fan comes on. If not, its a corgi job to diagnose the problem.

If it does go live, it probably needs a new pcb, in which case let me know.