It sound like you are playing with a BOMB. I am not one that would normally suggest going to a shop, because I have little or no faith in them, but in this case I think you need help. I would look very hard for input before committing to a repair shop.
There is no way the heater could have INCREASED the air it is taking in. For what ever reason your are gas flow is reduced and thus the need to reduce the quantity of air to maintain a flame.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles