F8
Input Circuit Fault
Mitsubishi Electric · R410A Systems
What does F8 mean?
A general fault has occurred in the input power circuit of the outdoor unit. This could be due to issues with rectifiers, filters, or other input components responsible for converting AC to DC power.
Repair Steps
- 1
Measure the incoming AC voltage at the outdoor unit's main power terminals.
- 2
Check the fuses or circuit breakers in the input power path to the outdoor unit for continuity.
- 3
Inspect for visible damage on the input power components (e.g., rectifier bridge, capacitors) on the outdoor unit PCB.
Verified technical data. Last updated: March 2026
Source: Mitsubishi Electric R410A Systems