Update: Person who sold me it was no help, bought a new unit and problems are persisting. It's something to do with the way I'm setting up the unit but I've spent well over 40 hours trying every possible way, keeping the probe under the tub, away from the tub, in the middle of the tape, near the edge of the tape, different types of types of tapes to secure the probe, a total of 4 different probes. The sensor is still wrong every time, it will stay at 85-87 degrees when the heat tape right where it is sitting at 130.