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Mitsubishi Electric Air Conditioner U8 Error Code
Outdoor fan stopped. Here is what it means and how to clear it, easiest fix first.
The outdoor unit stopped to protect itself because its fan isn't turning at the right speed. Snow, ice or debris against the fan, a failing fan motor or a board fault can cause it.
Some outdoor unit series describe U8 as a fan protection stop, others as abnormal outdoor fan speed.
How to fix Mitsubishi Electric U8
Switch off the power
Switch off the breaker for the system and wait for everything to stop moving.
Clear snow, ice and debris
Wearing gloves, clear snow drifts, leaves and branches from around the outdoor unit and its fan grille. Let ice melt on its own rather than chipping at it, and don't reach through the grille.
Reset the power at the breaker
Switch off the breaker that feeds the air conditioner (some systems have separate breakers for the indoor and outdoor units, so switch off both). Wait about five minutes, switch the power back on and restart the unit to see if the code clears.
When to call a technician
If the fan is clear and U8 returns, a technician needs to test the outdoor fan motor and board.
Parts that commonly cause U8
- outdoor fan motor
- outdoor fan blade
- outdoor control PCB
Order parts by your exact model number so they fit.
Other Mitsubishi Electric air conditioner codes
- Blinking OPERATION lightWall unit's indicator light is flashing
- P1Room air temperature sensor fault
- P2 / P9Indoor coil temperature sensor fault
- P4 / P5Drain sensor or drain pump problem
- PAShut down to prevent a water leak
- P6Freeze or overheat protection
- P8Pipe temperature error
- PbIndoor fan motor error
- FbIndoor control board error
- E0-E5Wall controller communication error
- E6 / E7 / E9Indoor and outdoor units aren't communicating
- U1 / UdHigh pressure or overheat protection
- U2Discharge temperature too high or low refrigerant
- U3 / U4Outdoor temperature sensor fault
- U6 / UP / UFCompressor overcurrent
- U9 / UHPower supply or current sensor problem
- PLRefrigerant circuit abnormal
Frequently asked questions
What does U8 mean on a Mitsubishi Electric air conditioner?
The outdoor unit stopped to protect itself because its fan isn't turning at the right speed. Snow, ice or debris against the fan, a failing fan motor or a board fault can cause it.
Can I fix Mitsubishi Electric U8 myself?
Often. The first steps above are safe checks a homeowner can do. If they don't clear U8, the cause is likely a worn part that needs replacing.
What if U8 keeps coming back?
A code that returns after a reset and the checks above usually means a part is wearing out. Note when U8 appears (which cycle, how often) and have your model number ready; it helps a technician bring the right part on the first visit.
Last reviewed 2026-10-19. Codes and steps can vary by model; check your owner's manual.