Display shows F3; unit stops and may beep repeatedly.

Safety: Switch off and unplug the unit.

Steps:

• Reinsert tank: Remove the water tank and reinstall it firmly until it is flush with the cabinet. Ensure no foreign objects are in the tank cavity.
• Check tank body: Inspect the tank for cracks or broken tabs that actuate the internal switch. Replace the tank if the actuator tab is missing.
• Inspect switch: With the tank removed, locate the tank detection lever or micro‑switch inside the cavity. Manually press it and listen for a click. If it feels loose or does not click, the switch may be faulty.
• Electrical test (technician): Test the micro‑switch for continuity when pressed. Replace the tank detection switch if defective.