Quick question, I finally got my Lopi Freedom Bay installed (pictures of the install coming eventually) and am now burning it for the second time. During both burns the air tubes at the top of the insert have started to glow a dull red. There is no red glowing on the insert outer shell(I checked with the lights off), just these air tubes. Is this normal or do I have it too hot in there? My thermometer on top of the insert is cruising right around the 690° mark at the moment and the tubes are still dull red. Thanks in advance.