I have a Ferroli Opimax HE 38C 4 years old,
When I turn ON DHW run's hot and then goes cold
A03 come up, sensor fault ,I have been told that the fact i can reset the boiler and it will start up again and then run hot again and then goes cold that the sensor is operating correct.Could it be the pump not pushing water through at right rate,any idea,I in Dublin and local ferroli engineer has be out a number off times,trying for the last two week to get him back,anyone know anyone in Dublin that knows about theses boilers,

Hego1, October 2011

HI ltd
Thanks for your comments,would the heat exchanger also effect the heating side of the combi,

Hego1, October 2011

hot water heat exchanger is block drain down system shut main water supply to boiler undo it and clean it with spirit of salt,refil system take air from pump and radiators

ltd, October 2011