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