I've been running a solo 30 since thanksgiving and im having a hard time getting more than a 6 hour burn. Apx. 2000 sq. ft. center chimmney cape, 3 zones usually have upstairs and downstairs turned down so when last load of wood goes in just the main living space is calling for heat. The wood is mostly ash and oak and is dry.Do I need to dampen down the draft fan? I know part of the problem is I call it a night way to early but that can only be adjusted on the weekend. anyone having any better luck on longer burn times?