We are having a problem with our new Napoleon Fireplace NZ6000. The glass fogs then burns on. We have to scrape it off with a razorblade.
Your wood probably is not dry enough, or your dampering it down to much. Not familiar with that model and assuming it's a wood burning fireplace that is.
yes your wood is wet try leaving the door crack opened a little when you start it up after it get going you can close it up.