Thanks. Did not know such a thing existed. Found it online and worked out how to do it. Instructions suck, so anyone else needing to do it, this is how.
Press and hold the Program button. While holding it, tap the time/sensor button but DO NOT release the Program button. A couple of seconds later, the screen will change. Then you tap the time/sensor button one time to move to the temperature calibration screen. Use up/down arrows to change. Move slowly, it has to re-calculate between pushes of the buttons. When done, hit Program button and it returns to normal screen.
Solar powered smart home thanks to Outback Power and Insteon products.