Hi- new to group. I have a Vermont Castings Model 2100 WInterwarm- love it!! I am having trouble this year with the damper not shutting when it is hot. It works fine when it is cold, but as soon as I get it hot (when I want to close the damper!) it won't. Per the manual I tried cleaning the nut, luricated with "high Heat Pam" and it opens and shuts better when cold, but still not when hot. Any suggestions? Thanks! Tonya, Winchester, VA