Mine is completely stuck. Won't budge. Then I remembered that I checked it this summer and couldn't get it open and would 'get back to it later'. Well, forgot and now I have a problem. Resorted to drilling 1" hole and clearing it with a reversed shop vac. Drafted better right away. Plugged the hole with a 1" nipple with a cap on one end. I'll have to get a new cover next summer during shutdown. Poor maintenance on my part. Cleaned out the firebox, but put off the chimney and forgot.