This is (I think) the fourth season burning with the F602 N; I had one year of the old 602 before that. It's always burned hot, but I've had some issues controlling it the last couple of weeks. It now likes to burn HOT, with the cooktop touching 900'--this isn't quite as hot as it seems (the cooktop is routinely 200' > than the rest of the stove), but just off that it's still 700-750' for a while. Just at rear exit it's never more than 500'. This seems to happen regardless of how much/when I turn down the air. I've tried turning it down in increments, keeping it just above a smolder. Eventually it still heats up. The other problem with this is that once I have the air all the way down, it burns real hot for a while, and then seems to coal early (too little air), with the firebox still fairly full. I then need to turn the air back up to get it to burn down. Overall, I'm actually getting pretty long burn times (3-4 hours). I rebuilt the stove earlier in the year, and am worried about a leak. Can't find one though. Went around with a little smoke, and didn't see any uptake around the seams or door. Secondaries are firing better than they have in the past, and I'm getting fairly lazy flames even when it's hot. So I'm wondering if this is actually how it's supposed to behave. I have a 25-30' chimney straight up, and I'm finally burning super dry 3yr oak for the first time, mixed with bricks (it acts the same with all wood though). While it just started the last couple of weeks, that's the first time since the rebuild that I haven't had any shite wood mixed in.