While you wait for answers, we may have found some information which could help you.
Click here for Ariston Clas SystemI have an Ariston Genus boiler. Fault showing 30 40 50, I can't find manual?
ariston boiler slow to ignite?
No display on Ariston e-combi approx3yrs old?
Error light blinking (orange colour) on Ariston e-combi boiler?
Why does my boiler remain ON - even when switch is moved to OFF?
Ariston Microgenus 23 MFFI PCB Defect?