Humidifier shows F1 and stops producing mist.

Safety: Unplug the humidifier and empty the water tank before inspection.

• Clean float chamber: Remove the tank and locate the float assembly in the base. Lift the float and check that it moves freely. Clean any limescale or slime with a soft brush and mild vinegar solution, then rinse and dry.
• Check float magnet: Ensure the float has its embedded magnet intact. If the float is cracked or waterlogged, replace the float assembly.
• Test reed switch: With the unit unplugged, access the small reed switch under the float chamber (often a glass capsule on a small PCB). If the float moves but the unit still shows F1, the reed switch may be defective and should be replaced.
• Reassemble and test: Refit the tank, fill with clean water, and power on. If F1 persists, the water level detection circuit on the main PCB may be faulty and require replacement.