Thermostat displays E11 and indicates an internal memory or configuration error; settings may not save.

Safety: No high‑voltage work is required. Do not open the thermostat casing.

• Soft reset: Use the menu to perform a soft reboot of the thermostat if available.
• Factory reset: Back up or note your schedules and settings, then perform a full factory reset from the settings menu. Reconfigure the thermostat and check if E11 clears.
• Firmware update: Connect the thermostat to Wi‑Fi and use the Bosch app to check for and install any available firmware updates, which may correct memory handling issues.
• Stable power: Ensure the thermostat has a solid 24 V supply (no E08/E09 issues) to prevent further write interruptions.
• Replace if recurring: If E11 returns frequently after resets and updates, the internal memory is likely failing and the thermostat should be replaced.