I just got my Brewer's Edge Temp controller II. I'm using it with a fairly new chest freezer and a thermowell in a glass carboy. I have set the temp to 66 degrees with a differential of 2. However, it seems to keep getting the beer pretty significantly below the 64 degrees that differential should allow. I woke up this morning and it was at 62 degrees.
I also noticed that the chest freezer's light was on, even when the temp probe was reading 64.
Does this seem like the product might be defective? Or perhaps I've missed a critical configuration step? All I have done is set the SP (set point) and DiF (Differential).
I'm not worried about the beer really - just was expecting this to give a little tighter control.