My Ferroli F30 works well except when the heating is on the pressure in the system goes over 3.5 bar and the P.R.V dumps the excess as it is supposed to do. The starting pressure is 1 bar. I understand from the manuel the normal running pressure is 1.5 to 2 bar. When the system has cooled down the pressure is 1/2 a bar. All the rads are getting hot. Any help would be appreciated.

Jeff Bridgend, May 2009

Problem solved,
The Shrader valve on the expansion vessel had failed.
All the air pressure had been lost. I replaced the valve and repressurised the tank. It all works perfectly now. Tulas you were not far off the mark.
Thanks

Jeff Bridgend, May 2009

expansion vessel goosed or pipework 2 it is blocked

tulsa mclean, May 2009