We purchased a used Whitfield Advantage (1994) 4 years ago. Finally got it hooked up. Ran great for 3 days. Not it won't stay lit and smoke fills room. Checked the damper arm and tried to adjust a bit. As soon as I released the set collar it pulled even closer to stove leaving abut 1" between knob and stove. Now it won't budge at all, in or out. Any solutions?