Is this a symptom of  overfiring my month old Quadrafire 4300 ? 
I use a magnetic thermometer on the outside of the single wall stovepipe and keep it reading under 550 at all times, usually at 350-450. (Dealers's suggested temps...)
Should I be concerned about this discoloration?
	
		
			
		
		
	
				
			I use a magnetic thermometer on the outside of the single wall stovepipe and keep it reading under 550 at all times, usually at 350-450. (Dealers's suggested temps...)
Should I be concerned about this discoloration?