H1 appears on an Argo humidifier and it stops producing mist.

Safety: Turn off and unplug the humidifier before removing the tank.

Steps:

• Refill tank: Remove the water tank, fill it with clean, preferably demineralized water, and reinstall it securely.
• Check float: Inspect the float inside the tank or base. Ensure it moves freely and is not stuck by scale or debris.
• Clean scale: If there is mineral buildup, soak the float area in a mixture of white vinegar and water, then rinse thoroughly.
• Check reed switch: In the base, locate the water level reed switch aligned with the float magnet. Test continuity while moving a magnet near it. Replace the Argo humidifier water level reed switch if it fails.
• Reassemble and test: Refit the tank, restore power, and confirm that H1 clears and mist production resumes.