I've noticed lately that when I shut the ol reg buck down for the night burn my flue temps just go nuts like up to 500-650* like a rocket and stay there for a while . Maybe a half hour to an hour then slowly creep back down and I don't get the burn time out of it at all. I only put like 3-4 splits in the stove and it does this . I'm thinking air leak from somewhere or something any thoughts would be appreciated thanks.