i have a wood wind stove double doors in front ,,,,with large top,,the doors have draft knobs on them,,when i bought the stove used ,,,,it came with a modi-fyre ,it is a combustion stabilization system,,,do i need this ????and do i close my front vents when in use,,,when i first light the stove it smokes a back draft some times ,,,,i have ss chim,,8 inch ,,3 3 feet stacks and tee and 18 inch going in the house and the 12 inch modi-fyre and 6 inch in to stove let me know