I’d like to use the ITC-308 to keep some condition beer from freezing. I have the beer in my garage as it gets very cold there in the winter. So I’m trying to use the ITC-308 just to keep it from freezing, basically in the 35f-40f range. I have a heating mat wrapped around the carboy and nothing plugged into the cooling plug. I’ve tried different configurations of the target and differential settings, but can’t quite get it to stay in the 35-40 range - it’s always above 40. How might I accomplish this?