Daikin mini_split Error Code A0

What does A0 mean?

System protection device (pressure switch or thermal protector) has activated.

Common causes

• High discharge pressure - dirty coil
• Low suction pressure - refrigerant leak
• Compressor overtemperature
• Electrical fault

Diagnostic & testing steps

1. 1. Check for P1 or P4 fault flashing together
2. 2. Inspect outdoor coil for dirt or blockage
3. 3. Measure refrigerant pressure with Daikin-compatible manifold
4. 4. Check refrigerant charge - Daikin uses R-410A or R-32

Tools required

• Daikin manifold gauges
• Leak detector
• Thermometer

OEM parts & part numbers

Refrigerant, High Pressure Switch

Part numbers: 5002430

Safety warning

⚠️ Daikin mini-splits use R-32 in newer models — flammable refrigerant. Special handling required.