While you wait for answers, we may have found some information which could help you.
Click here for Boiler 28 PressureAriston Microgenus 23 MFFI PCB Defect?
error code e02 wont work when pressurised?
ariston boiler slow to ignite?
No display on Ariston e-combi approx3yrs old?
Error light blinking (orange colour) on Ariston e-combi boiler?
boiler keeps going out?