Many thanks for information on this website.I fixed my boiler problem in 10 minutes after finding the answer here. My 21 year old potterton neaterheat 16/22 was playing up intermittently. The pilot lit but it did not always fire up to main jets. After reading various answers on this site I decided to look for dry joints on the PCB. Five minutes later the PCB was pulled out, 3 suspect dry joints were resoldered. Pcb replaced and bingo! it's worked perfectly ever since, cheers.
