The OFFSET setting is shown as number of degrees (default = 4F). It is similar in nature to the Swing setting, however, it only effects the operation of the second (auxiliary) heating stage of your system.
The auxiliary heat is there for when your system can’t keep up with your target temperature.
You can adjust the value from 0 to 9 which corresponds to 1F to 9F degrees to determine the number of degrees that the room temperature must fall below the set point, before requiring the second heating stage to turn on. This can be used to conserve energy in cases where the second heating stage is costly to operate.
NOTE: While making these adjustments, you have to make the keystrokes in a timely manner, as the thermostat will timeout automatically and exit these screens after 10 seconds without a button press.
If you set the offset at 0, this will disable the 2nd stage completely and provide maximum energy savings while sacrificing comfort.
A higher offset number results in energy savings while a lower offset number provides more comfort.