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. 1

    Check the outdoor unit's display or LEDs for more specific fault codes or diagnostic indicators.

  2. 2

    Verify stable power supply to the outdoor unit's main terminals.

  3. 3

    Inspect the outdoor unit PCB for any visible damage, tripped protection devices, or abnormal component temperatures.

Browse all codes in this manual (60)
Verified technical data. Last updated: March 2026

Related Faults

Source: Mitsubishi Electric R410A Systems