I'm starting my second year with my Drolet HT2000. I am using wood that has been seasoned 5+ years. I get my stove up to temp, 500+ stovetop 270 or so 18" up the single wall pipe. My secondaries are kicking it good. Everything seems perfect inside. I go outside and there is visible smoke coming from my chimney Everything I read on here states that I should be smoke free. What am I doing wrong???