While you wait for answers, we may have found some information which could help you.
Click here for Heating Radiator Pressure
Replace a diverter valve?
How turn off heating in Ferolli Optimax 31c?
ferroli plus 31c has a code b2 any ideas?
F40 fault?
Ferolli Optimax HE 31C expansion vessel change?
Hi how to increase the water pressure on ferroli optimax 25C?