HI, I HAVE THE TRICITY BENDIX SIE545P (PYROLYTIC) COOKER AND RECENTLY THE CATALYST FELL OUT AND SMASHED, SINCE THEN THE COOKER JUST GETS HOTTER AND HOTTER NO MATTER WHAT THE HEAT SETTING. IS THIS THE THERMOSTAT OR IS THE BROKEN CATALYST THE FAULT?.......OR IS IT KNACKERED!!!!!!