Error Code P8 in Air Conditioning

The P8 error code is associated with anomalies in the outdoor unit of air conditioning systems. Its exact meaning varies depending on the brand of the equipment. Below is a detailed guide with interpretations and recommended steps to resolve this error for different manufacturers.

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Interpretations of the P8 Code by Brand

Orient and York:

• Meaning: Overcurrent protection in the outdoor unit.

Sharp, Carrier, Mr. Cool, GREE:

• Meaning: Overtemperature or high temperature in the compressor controller, the IPM (Intelligent Power Module), or the PFC (Power Factor Correction).

PIONEER and TCL:

• Meaning: Detection of overtemperature or out-of-range temperature in the outdoor unit.

TRANE and MIDEA:

• Meaning: Typhoon protection.
• Actions: This is a preventive measure to avoid equipment damage during severe weather conditions.

Daikin:

• Meaning: Protection against freezing of the heat exchanger during automatic refrigerant charging.
• Potential Causes:
  • Low ambient temperatures.
  • Inadequate refrigerant flow.
• Actions:
  1. Close the refrigerant cylinder to stop the flow.
  2. Restart the charging process from the beginning.

Mitsubishi:

• Meaning: Compressor-related issues, overheating, phase inversion, or thermistor failure.
• Actions:
  1. Check and correct the wiring between the indoor and outdoor units.
  2. Identify and resolve phase inversion issues or protective device failures.
  3. Measure the resistance of the thermistor in the outdoor coil; if defective, replace the control board.

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General Procedure to Resolve the P8 Error

1. Clean the outdoor unit:
   • Ensure the heat exchanger has unobstructed airflow, free of dust or dirt buildup.
2. Inspect the outdoor unit’s fan:
   • Confirm the fan operates correctly and is not blocked or damaged.
3. Diagnose the PCB board:
   Inverter systems have a PCB board divided into three parts:
   • Main board
   • Filter board
   • Control board
   Steps to check for faults in the control board:
   • Turn off the equipment’s power supply.
   • Open the outdoor unit and access the control panel.
   • Remove the control board, discharge its static electricity, and clean it properly.
   • Check the IPM circuit, which can overheat if heat transfer to the heat sink is inadequate due to a lack of thermal adhesive.
   • Apply new thermal adhesive between the IPM circuit and the heat sink, securing them properly.
   • If the issue persists, replace the IPM circuit or the entire control board if necessary.