And was your bd installed on a max caddy? Or on a stove?This furnace must be connected to a chimney certified for use with wood burning heating appliances. A 7-inch chimney and connector must be installed for the Max Caddy if it is used as a wood-oil unit, a wood-electrical-oil unit or if an oil option may be installed in the future. If the furnace is to be used as a wood only unit or a wood-electric, then a 6-inch chimney is recommended. The unit is not to be connected to a chimney flue serving another appliance. If the chimney draft exceeds 0.06 IN.W.C., a barometric draft control should be installed on the smoke pipe. Never install a manual damper. The barometric control must be adjusted so that the maximum draft measured at the furnace outlet does not exceed -0.06 IN.W.C. Please note that a draft exceeding 0.06 IN.W.C. could produce an uncontrollable fire. On the other hand, the minimum draft required is 0.04 IN.W.C. in the evacuation pipe on the wood side, no matter what type of furnace (WOOD, WOOD/ELECTRIC OR WOOD/OIL). The adjustment should in no case be modified to increase combustion.