No this is problem is happening because the expansion vessel with in the boiler is flat or the diaphragm is burst. To test remove the shredder cap from the expansion vessel located at the back of the boiler, push on the pin. If water comes out then the diaphragm within the vessel is burst (new expansion vessel required) if nothing comes out then the vessel is flat (use a bicycle pump with a guage and pressureise to 1bar.)
Simon, March 2009
