Honeywell RTH2310 - Getting Started; Initial Setup Steps

2. Tighten the screw and install the coverplate.
3. Turn power back on at the heating/cooling system.
System Setup
1. Press both and buttons simultaneously for 3 seconds to enter or exit the setup menu.
2. To advance to the next function, briefly press both and buttons simultaneously.
3. To change the setting, press the or button.