I have a Vermont Castings Vigilant Wood Burning Stove installed in 1984. Sometimes when running it, the damper sticks. That makes me "manhandle" the damper handle leading to cracking of porcelain and it also pivots up too high. So, in order to reopen the damper so I can add wood, I open the top griddle plate an inch or two and poke the damper with my wrought iron shovel. Sometimes it sticks, sometimes it moves freely. Not being able to see inside the stove (when it's cold) very well, I have no idea why it's hanging up. Any ideas?