I just replaced my old temperature probe/sensor. It was reading in excess of 130F and would not let my spa heater run. I looked for an original Pentair TS5T but could only find the Pentair TS5L, I just installed this and initially it appeared to be reading temperature correctly as it showed the same temperature as the water. However, when I fired up my spa to check to see if it would read the higher temps, it continued to read 90F even when the water temp had climbed above 102F and shut off the heater. I attempted to calibrate through the my easytouch menu to the proper temperature but it would keep defaulting back to 90F after exiting the menu. The last one I installed about 6 years ago (TS5T) didn't even need to be calibrated. Do anyone have an idea why this would be the case? Is the TS5L not the compatible? perhaps I ended up with a bad one? Thanks in advance for the help.