We bought our house in July & had the sweep come and inspect & clean the fireplace. Wood burning, located in the basement (walk out). He replaced the cap on the chimney at that time. We have used the fireplace a handful of times since. Last night went to start a fire & the damper wouldn't open. It's a pop up/lock top kind located at the top of the chimney, unsure of the brand/make. Pulled the cord & nothing, tried pulling quick, hard, etc. and it wouldn't pop open. We're thinking it's frozen - we've had rain & snow and yesterday a blizzard (which is continuing today). How can we get this thing to thaw/open? I've tried searching this forum and online for answers, and left a message with our sweep to see if he has ideas, he's SLOW to respond. Ideas?