What was I thinking -- it must have been on sale. Anyway I already had two Hova-Bator Incubators, one old one with built in fan and another ancient one with just the thermo-disk heating element. Both give me decent hatches. So a few years ago I purchase the still air "Little Giant" 9200 with the circuit board, which when set up held the temperature just find. A little later I installed a separately purchased incubator fan. Well the temp went up well over 100 even with the adjustment knob all the way down! Checked all my installation procedures on the fan (like not having it upside down) and couldn't find any problems. Oh well, just use it as is for the season. So this years, pull it out again and re-install the fan. Same problem, temps just skyrocket as soon as the fan is turned on. Maybe some weird problem with the fan itself Take apart an old computer and get the fan out of it. Install -- same problem. Temps are fine until the fan is turned on. Okay, maybe the fan is too close to the heater, so I hang a piece of of Styrofoam between the two, still no difference. It's almost like the fan unit(s) are causing some interference with the heater/circuit board. I'm totally stumped! I just don't understand this. Still getting okay hatches without the fan and just the turner, but I'm sure it would be better with the fan. Anyone have any ideas. Was thinking of just setting the fan on the bottom of the unit in the corner, just to get a little circulation going and not having any eggs close by. PS- My temp readings are correct -- have check with 3 different thermometers that I use in my other units.