I'm new to advanced wood burning but I've been reading this forum for the last month and everyone here is great. I now know what a secondary burn is. hehe. So anyway, I have a new Lennox Montecito and I get brown deposits on the glass covering maybe 4 - 5" at the left side. Hopefully my attached photo shows this, or you can see it in my signature picture. I've used a variety of woods, all seem dry to me. I only see smoke during the startup. The brown stuff cleans off with a rag dipped in ash (thanks to this forum). I've tried leaving the air all the way open and closing it to 1/2 but it didn't make much difference on the glass. From various threads here, I'd guess either my fire isn't hot enough, I have a leak on the left side, or I'm being too picky expecting perfectly clear glass. Can I get your thoughts on this please? Oh and this thing is amazing how much heat it puts out.