I have my baro set at .02 and take my reading right at the exhaust outlet, when it gets warm and muggy out I will have to turn up the 24/7 blower setting or I will get an out fire. My exhaust temp when I last checked in early nov was around 240 if I remember right. I am trying to run the unit cooler as well this yr, 150F instead of 180 like last year. The way I figure it you extract more heat from the exhaust the cooler the water is, its not a linear relationship, the down side to this is I think I'm getting a little less BTU's out than before, but my coal is burned nicely (last year I ran with 1/2" or so of ash at the end of the grate, now I have maybe 1.5"). I've been supplementing with wood inside recently and its been helping with the boiler load quite a bit, 16F here this morning.