While you wait for answers, we may have found some information which could help you.
Click here for Warning Hot WaterFerroli DOMIcompact F 30 D?
Ferroli domicondens he26 C fires up but doesn't appear to rectify ?
F40 fault?
ferroli plus 31c has a code b2 any ideas?
Connections on Ferroli F24 Gas Valve?
Ferroli Optimax HE31c a26 problem?