I have burned wood for 25-30 years. 7 years ago I purchased a 52 bay Appalachian catalytic stove. Has been a great stove. Have had typical maintenance, clean/ inspect chimney every other week. Vacuum catalyst 1 to 3 Times a season. However I am on my 3rd set of catalysts in this 7 year time. 2 months ago put in anew set of them stove burned great following cat temps between 1200-1500. Stove temps around 550. The last 2 weeks I have not been able to get stove temps above 450 ish. Cat tempsaround 1000-1200. When the door is open a lot of smoke in the firebox. Outside looking at the chimney crystal clear, no smoke at all. Wood is seasoned and dry.And chimney is clean. Only thing I can think of other than a faulty catalyst issomehow intakes have become plugged. Anybody have a 52 bay Appalachian that can give me a little help? Have tried calling the manufacturer, however they are like talking to a brick wall. Any ideas?