I wonder if it is just the 190 stat, my 190 stat always seemed to run a few degrees over the 190 deg, even in the sub freezing weather. It can be warm there (saw temps of 98 deg), I was just there for the 4th of July week - had a great time The temp isn't too bad when playing on the boat and in the water. haha I was actually quite surprised how my temps stayed in the 203 - 206 range for the most part this July with only the electric fan. I was expecting it to vary much more than it did. I was also down there the first week of June and had it all stock - stat, both fans, etc. My temps that week were also 203-206 and nice and stable. Though it wasn't quite as hot as in July. Last year with both fans, 190 stat, and the Big Horn inserts under similar conditions, my temp wouldn't come down below 210 deg. @ 70+ mph until the ambient temp dropped to below 94 deg. This is all still using the shutter system.