i got a 2nd UTH for the cold side for the winter cuz in the winter it can get to 15*F at times during the winter. i have a thermostat for both and i have a red light 24/7 on a rheostat low setting for the ambrient temp. i havent changed anything in a while. i occasionally adjust the thermostat a lil bit but everything stays right where it should be most of the time