Smart thermostat shows incorrect time or 'Time Sync Err'; schedules run at wrong times.

Safety first: No mains work is required; this is a configuration/low‑voltage issue.

• Check internet: Ensure the thermostat is online (no 'No Signal' or Wi‑Fi error). Fix connectivity first if needed.
• Set time manually: In the thermostat settings, manually set the correct time and date, and verify the correct time zone and daylight saving settings.
• Enable auto‑sync: If there is an option to sync time with the server or network, enable it and force a sync.
• Firmware update: Apply any available firmware updates via the app or thermostat menu, as timekeeping bugs are often fixed in updates.
• If time drifts rapidly: The internal real‑time clock circuit on the PCB may be failing. Replacement of the thermostat is usually required.