First it stayed on the temp I set it on during the calibration no matter what. I reset the probe to factory default and then it read 8.7 F. I calibrated it one more time to my tanks temp using a glass thermometer for the target temp. I tested it by putting it in colder RO water and the temperature went UP! Anybody have any idea what is wrong? Any advice is greatly appreciated as this set up has been a PITA and I can never get a response from the company.