There's your problem. Yes, it's too high. I have one that I had problems with, but in the opposite direction. TOO cool. Talked to a few others and it appeared that this was common to this particular brand. Bumped it up above the 99.5 pre-set, to 102.5 on the thermostat, and the thermometers I have inside then registered right where I needed it to be, and after that I started having better hatches. You might try bumping the Incuview down a couple of degrees, doing a couple of tenths of a point at a time, letting it stabilize, and then testing with the thermometer inside to see where it registers at, to bring it down to the ideal of 99.5.