This is the second time in two years my chiller has "gone bonkers". I was reading the temp and it was @ 54 deg C. No freaking way! The failure was the thermocouple that is inserted into the chiller (2nd time). It is a good thing I can repair and know how to. The replacement TC's are very cheap and available on Ebay. The replacement procedure is very easy. Disassemble and replace, no soldering just a small screwdriver to connect it to the display/controller. 1/4 hp chiller.
The caustic nature of the nutes eats the coating away then into the T/C. Here is a picture of where it made contact. The next T/C's I look for will be incased in stainless (I hope).