While you wait for answers, we may have found some information which could help you.
Success
Message
2 amp fuse blown?
DHW running hot then cold?
DHW Run's hot and then goes cold?
c/h hotwater?
shower in bathroom keeps going hot then cold then hot etc?
High pressure on my Optima Ferolli 901 central heating?
Can't get hot water but central heating is working fine, any ideas??
how can i fix this ?
ferolli modena 102?
Ferroli Boiler Optimax HE 31C?
falling presher?
what part do ineed?