Hi
Know exactly how frustrated you might feel. Had the same problem. First of all fan was replaced, but every time cover put back on it light would flash again. Then a new circuit board was added (almost £200). This was then found to be faulty! A new board has since been added. So far no problems, but apparently combi boilers don't have as long a shelf-life as older ones. Hope this helps somehow, also check for any small plastic parts which need replaced due to melting.
Jeannie
March 2010