While you wait for answers, we may have found some information which could help you.
Click here for Ariston Combi Boiler Watererror code e02 wont work when pressurised?
gas boiler keeps going to reset?
No display on Ariston e-combi approx3yrs old?
boiler keeps going out?
Ariston Microgenus 23 MFFI PCB Defect?
Why does my boiler remain ON - even when switch is moved to OFF?