My infrared thermometer only said 550-600on the pipe air was all the way open but had not been burning very long maybe 30 min and the wood is wet ash, I shut it down and turned on the fan and it stopped turning red then turned red again a little later. Stove top temp was 350 but it is hard to find a good place to measure that on the t5 insert. How hot do those stainless flex liners have to be before they turn red? Was that an over fire?