As of late the stove has been professionally cleaned. The damper is set about .5 inches out from the box. I can only get the stove to stay lit between fan speed 4 and 5. If you try to start stove in manual mode with fan speed at 4 or below the stove will stop feeding and put itself out after approximately 20 minutes. Then error 4 and 3 are flashing when you open the cover. The magnetic connections are working fine. When you make contact with the magnets you hear the stove operating normally. I reset the high temp sensor under the control panel as well That did not help. What has failed now? Exhaust fan sensor??