"fan fault flashing on the front why is this"
The electronics in the boiler have detected a problem
Either the fan is defective
Or the pressure device that senses the fan is running is defective
Or the electronics are giving a false indication
"can we fix it"
possibly but diagnosis may take you a long time and sourcing spare parts could be a trial for you.
A reliable, certified boiler engineer is probably your best approach
Good luck...
Peccavi, March 2009
