i have a king 5500m modle pellet stove. it worked awsome for three years but this year i been having problems with black soot on the glass a real lazy flame an my exaust blower seams to surge. i cleaned both fans and chimlybut the problem never went away i also changed the door gasket and window gasket i realy love the stove just cant get it running great.if any body has an idea of what it could be please let me know your thoughts