Thermostat shows F5 and schedules or learned behaviors do not operate; device may revert to default temperature settings.

Safety first: Turn off HVAC power before removing the thermostat if you need to handle the device physically.

• Backup settings: If the thermostat is still partially functional and connected to the app, export or note your schedule and configuration.
• Firmware update: Use the Payne app or update mechanism to install the latest firmware, which may correct memory handling issues.
• Factory reset: Perform a full factory reset from the thermostat menu. Re‑enter your system configuration and schedules manually.
• Monitor stability: If F5 recurs after a reset and update, the internal memory chip is likely failing.
• Replace thermostat: Memory components are not field‑serviceable. Replace the Payne smart thermostat to restore reliable schedule storage.