Hi, ive recently become gas safe registered and have come across my first s..t boiler job!! Im having problems with an ariston microgenus 24, it has a01 fault code. when there is a demand pump runs, fan runs, air pressure switch ok, no spark from electrode. Pcb was replaced and no electrodes are sparking but boiler still doesnt light!! There is power to the gas valve, and the gas valve was replaced 3 months ago!! Any ideas greatly appreciated!!!