problems with chaff combi 80?

If the bolier lights but the electrodes keep sparking, and you have replaced the flame sensing probe, check the following:
A decent earth, Test from earth point on boiler to a known good earth supply
Polarity is correct between L&N
Readings should be
L to E ~240v
L to N ~240v
N to E 0-15 vac

If these are correct, visually inspect the flame sensing lead, otherwise it's pcb

Carefree
July 2010