I'm trying to calibrate my solar sensor, as I just don't believe what it's telling me. In the EasyTouch manual, it says to put the EasyTouch into Service mode, press the Filter Pump button, and then go to Settings->Calibration to calibrate the sensors. This works fine when I try to calibrate the water and air temperatures, but when I change the temperature on the solar sensor, it doesn't stick (it just goes back to the temperature it was at before). What am I doing wrong? How do I get the solar calibration to stick?