What is wrong with my Glow worm 60FF boiler?

My Micron boiler has developed a fault ie the preset and burner lit lights keep alternating. The book say "software sequence error" Is this a major fault and is it going to cost me a fortune. It was installed in Dec 2003. I am a pensioner living alone and am afraid that if I just get a name out of the paper I will not know whether they are qouting a fair price or not. Any advice anyone can give me would be very much appreciated. Thank you