What P6 means
Freeze protection (during cooling) or overheat protection (during heating) operated.
Also shown as: 6 blinks, depending on the model.
Likely causes
- Dirty air filter
- Blocked airflow
- Fan problem
- Refrigerant problem
Safe first checks
- Turn the system off and clean the indoor air filter.
- Make sure furniture or curtains aren't blocking the indoor unit.
When to stop
If P6 returns with a clean filter, call an HVAC technician.
Checked against: Mitsubishi Electric, Mr. Slim indoor/outdoor unit malfunction-diagnosis check codes (2024-11-18). Codes can differ by model and year, so confirm with your owner's manual.