Press the SELECT and SET buttons simultaneously for 3 seconds and release. You will see F for Fahrenheit or C for Celcius. Press and release the SET button and you will see 12 CLOC. Press and release the SET button and you will see the first stage differerntial. It is adjustable with the arrows from 1-3 degrees in .5 degree increments. When you are finished press the SET button and you will see the second stage differential. It is adjustable from 1-6 degrees in .5 degree increments. Press the SET button and you will see the second stage delay. It is adjustable with the arrows from 10-40 minutes in 5 minute increments. When you are finished you can either press the SET button until you reach the main screen or leave the thermostat and it will return to the main screen in approximately 20 seconds.