After a long period of operation, the following items of the air conditioner should be inspected:
• Abnormal heating of the power cord and plug, and even a smell.
• Abnormal noise or vibration.
• Water leakage from the indoor unit.
• Electrified metal cabinet.
Turn off the air conditioner if any of these problems occur.
It is advisable to carry out a detailed inspection of the air conditioner after five years, even if none of the above has taken place.