The Thermocouple is the device that monitors the fire after start-up. Once it reaches temperature the thermocouple allows the stove to start feeding on it's own in normal operation mode. If your stove goes out after the initial start-up cycle, more than likely the thermocouple needs to be inspected or replaced.
35″ Thermocouple Replacement for the Specified Models
1 Year Manufacturer Warranty
Quadrafire Thermocouple 812-0210 800/1000/1100i/1200 by QuadraFire