F3 displayed; interior light and fan may behave erratically; temperature control may be unstable.

Safety first: Disconnect mains power before removing the control panel or touching any wiring.

Steps:

• 1. Inspect the control panel: Check for signs of condensation, liquid spills, or cracks in the fascia. Dry any visible moisture with a soft cloth.
• 2. Remove the control panel: On many Liebherr models, the panel is held by clips or screws at the top front. Carefully pry or unscrew and pull forward.
• 3. Check the ribbon cable: Ensure the flat cable between the display/keypad and the main board is fully seated and not kinked or damaged.
• 4. Clean contacts: If accessible, gently clean the connector contacts with isopropyl alcohol and allow to dry completely.
• 5. Visual check of components: Look for burnt or corroded areas on the small interface PCB. If damage is visible, the panel should be replaced.
• 6. Reassemble and test: Refit the panel, restore power, and check if F3 clears. Test all buttons and temperature adjustment.

Note: If the error persists, the user interface module or main control board may need replacement. This is best handled by a Liebherr service technician.