Ferroli F30 boiler keep going over pressure, when on centrel heating?

My Ferroli boiler(f30) keeps going over pressure.As it starts at 1bar and warms up it goes up 3.5bar ,pressure valve is then opened.
rob, January 2009


done
ferroli f30 boiler keeps going over pressure

kel, January 2009
expansion vessel lost charge or faulty

cooper, January 2009
link Click here to see other fixes for Ferroli F30.