Humidifier or dehumidifier shows U1 and will not operate; often indicates abnormal room temperature.

Steps:

• Check room temperature: Verify the room is within the operating range listed in the Sharp manual (typically 5–35°C). Move the unit to a suitable room if necessary.
• Power reset: Unplug for 10 minutes and restart.
• Sensor check: If the room temperature is normal but U1 persists, inspect the ambient temperature sensor near the intake grille for damage or misplacement. Reposition or replace as needed.

Safety: Unplug the unit before accessing internal sensors.