FO isn't nice I am afraid, it means internal error which is usually a PCB failed.
Call them for fixed price repair, can sometimes be cheaper than local engineers 08457 256206.
Bunslinger
September 2009
It means F**K OFF!
HA HA HA sorry I just couldn't help it ....
J
September 2009
look in your installation book this is a fault code should tell what code means. What boiler have you got ? if you have not got book Ring boiler manufacturer!
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.