Hi there: We have a Quadra-Fire Santa Fe, purchased in '08. It has perform without event until now. It starts up as usual and then after 30-50 minutes, it starts to shut itself off. I have cleaned the pot, cleaned everything from pot to anything that collect ash, made sure the ceramic cover on the thermocupler in secure and in contact with each other, vacumn all fans, blew out the vacumn hose, reset all snap discs, removed auger and cleaned tube and checked motor and rebooted the control box by unplugging it. I am at a lost as to what else to do, without replacing everything. Any suggestions? Thanks in advance to the wealth of knowledge out in the web-a-sphere....