Thermostat displays E13 and indicates an internal memory or configuration error; may lose schedules or settings

Safety: No high-voltage work is required, but turn OFF power to the HVAC system before removing the thermostat.

• Power cycle: Turn OFF the HVAC breaker for 2–3 minutes, then turn it back ON. Allow the thermostat to fully reboot and check if E13 clears.
• Factory reset: If the code persists, perform a factory reset from the thermostat's advanced settings menu. This will erase schedules and custom settings, so note them beforehand.
• Firmware update: If supported, connect the thermostat to Wi‑Fi and check for a firmware update through the Ruud app or thermostat menu. Apply any available updates and reboot.
• Replacement: If E13 remains after reset and update, the internal memory hardware is likely defective. Replace the thermostat.