I am a new wood burner. We installed a freestanding stove into a huge hearth in a home we just purchased. Also installed was a stainless liner, cap, and connector to the stove. We've been burning for three weeks and have been really enjoying it. Now the issue- we just noticed this week that the stainless connector (from liner to stove) is turning black and the liner is turning a copper color. It isn't soot. It is some discoloration of the metal. I believe we have been burning good dry wood within the recommended temps. Do I have something to worry about here? Thanks in advance! If I don't here back I'm reluctant to fill it for the night and the dreaded oil heat will have to kick in..... $$$