We have a Lopi Republic 1750 installed in a room with 10' ceilings. There is (supposed to be) black double wall pipe up to the ceiling. there is a small connector from the top of the stove to a 2 ft section of pipe which connects to a long (maybe 6 ft) telescoping section up to the ceiling. My 2 ft section has developed a dulled look to it and where it connects to the long telescoping piece, it is almost scorched looking (if black can look scorched, but I don't know how else to describe it) around the seam and about an inch into the long piece. Is this something to be concerned about? We do not have a flue thermometer, but the stovetop thermometer consistently reads 300 - 600, with a few times getting higher. Thanks!