Have you used the product for a long time?
Have you checked if there is anything stuck between door and case?
○ Detailed answer
▶ Open the door and check if there is anything stuck between the door and case.
▶ Please check whether ventilation opening is clear.
▶ Please check that the product is not installed in an enclosed area.
(Make sure to have 10 centimeter distance between the wall and the product for ventilation.)