What setting do you have the ESU set at? If the ESU is set to 105, yeah it wont go on if it is that hot..think of it like a thermostat... but that is also too hot for your bp if thats what you are using this for. What were your digi temps running at? Sounds like something (digi temp gauge or ESU) may not be working right. Also, cool side should be between 78-80.. warm side 90, but no higher than 95, if you have a bp.