Diagnosis
Schedule corruption or conflict. This occurs when schedules are changed from multiple sources (device, app, website) or after a power interruption that causes memory issues.
How to Fix It
Set the schedule from one source only. Use either the thermostat interface OR the Total Connect Comfort app/website. Do not mix. To reset, on the thermostat, press Menu > Schedule. Select Clear Schedule for both Wake and Leave periods. Re-enter your complete weekly schedule directly on the thermostat. Ensure you press DONE after each day and period. Finally, confirm the System Mode (Menu > Preferences > System) is set to Heat, Cool, or Auto—not OFF or EM Heat.
If That Didn't Work
A weak or missing C-wire (common wire) can cause memory loss during short power cycles. Remove the thermostat from its base and verify a wire is connected to the terminal labeled 'C'. If no C-wire is present, the thermostat relies on power-stealing, which can be unstable and corrupt settings. Installing a C-wire or a Honeywell C-wire adapter is the solution.
Heads Up
If you use the 'Hold' function (pressing Temperature to temporarily override), ensure you understand the hold type. A 'Temporary Hold' reverts to schedule at the next programmed change. A 'Permanent Hold' cancels the schedule until you manually select 'Run Schedule'.