P8
Outdoor Unit Malfunction
Mitsubishi Electric · R410A Systems
What does P8 mean?
The outdoor unit has reported a general malfunction. This is a broad error indicating an issue within the outdoor unit that requires further investigation, as a specific fault code for the outdoor unit may not be directly displayed on the indoor remote controller.
Common Causes
- Overheating of the outdoor unit components.
- Refrigerant pressure issues (too high or too low).
- Electrical fault within the outdoor unit.
- Fan motor failure in the outdoor unit.
- Compressor malfunction.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Check the outdoor unit's display or LEDs for more specific fault codes or diagnostic indicators.
- 2
Verify stable power supply to the outdoor unit's main terminals.
- 3
Inspect the outdoor unit PCB for any visible damage, tripped protection devices, or abnormal component temperatures.
Verified technical data. Last updated: March 2026
Related Faults
Source: Mitsubishi Electric R410A Systems