This past weekend I was at a relatives house and he started up his wood burning fireplace insert, a "Fireplace Xtrordinar" that was installed by a dealer for the insert. After looking at the inside of the insert I made the comment that I thought he might not be burning it hot enough as it appeared, to me, there was a huge build up of creosote on the sides and the glass. As a matter of fact the entire inside looked like it had a thick coating of shinning black tar all over everything. He told me that the dealer told him to expect that. When the stove was burning wood you could not see through the glass at all to even know there was a fire burning. I will attempt to post a photo of the inside of the glass. What do you all think?