IT IS AN ILLEGAL OFFENCE AND ***VERY*** DANGEROUS TO LINK OUT OVERHEAT THERMOSTATS ON THESE APPLIANCES!!!!
Change your thermocouple, might be on it's way out. Also check that the thermocouple is tightened properly...
Additionally.... To change these components, you are breaking into the appliances' combustion chamber... This should only ever be done by a CORGI Registered engineer as failing to reseal this case correctly could be a fatal manouvre!
ccMods, July 2006