Why does my Falcon 9915L809355 boiler keep turning off. It happens anytime ?

ferroli falcon?
FER falcon?
intermittant faults tend to point to PCB
normally dry soldered joints on PCB or relay switches on PCB have become caked in carbon/sooting from arcing
if your handy you can try [after identifying first] resoldering the dry joints
or cleaning the dirty relays
alternatively you could just purchase a new PCB

manwithnoname
May 2012