If the gas burner stops burning, there is a chance that the HI LIMIT safety switch may be tripped. To reset the HI LIMIT press the red button one time. This may reset the burner. The HI LIMIT is set to trip at around 350 degrees but other factors could cause it to trip at a lower temperature.
The HI LIMIT is located inside the service panel on the end of the smoker where the instrument panel is. Once this service panel is removed the HI LIMIT is located on the side wall.