I can believe it! certainly a manufacturer to avoid.
Recently had no hot water (boiler fire, and flow heats) - classic diverter symptoms. Ferroli attend and "replace" the diverter motor, and then spend an age reprogramming the boiler. The optimax has a installation menu (ts codes), this is not mentioned in the manual but can be programmed by ferroli.
Could PCB setting cause what appears to be a diverter failure.
I suspect that the PCB may "forget" settings deliberately,and unless you are a ferroli engineer and know the settings could lead to a part replacement
Has anyone has experience of the ferroli TS menu settings?