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Carrier Air Conditioner F0 / P1 Error Code
Ductless overcurrent or voltage protection on Carrier air conditioners.
CarrierAll Carrier air conditioner codes
The outdoor unit stopped because current rose too far (F0) or supply voltage went too high or too low (P1). Carrier's causes for both start with the power supply and include a refrigerant blockage or leak, wiring, the board and, for F0, the compressor.
Compatible models
Both codes appear in the 40MAQ and 40MHH high-wall ductless service manuals.
Also shown as
The 40MAQ manual also lists P0 and P4. They point to the inverter module and compressor drive, and they're technician-only.
Difficulty
Start with the safe checks below; a worn part may need replacing.
Not sure you are reading the code right? See how to read Carrier air conditioner codes.
How to fix Carrier F0 / P1
Check for a power problem
Think about whether there's been a storm, an outage or flickering lights. Look for a tripped breaker for the outdoor unit and reset it once.
Clear the outdoor coil
With the breaker off, remove leaves and debris from the outdoor unit so it isn't straining. A dirty coil makes the compressor draw more current.
Wait and restart
Leave the power off for at least 20 minutes, then turn it back on.
When to call a technician
Stop and book service if the breaker trips again or the code returns on a normal day. Inverter and compressor faults involve high-voltage parts that hold a charge after power is cut.
Parts linked to F0 / P1
These are the parts most often behind this code. Tap one to see what it does and the signs it is failing.
Order parts by your full model number so they fit.
Frequently asked questions
Which Carrier models show the F0 / P1 code?
Both codes appear in the 40MAQ and 40MHH high-wall ductless service manuals.
Can I fix Carrier F0 / P1 myself?
Often. The first steps above are safe checks a homeowner can do. If they don't clear F0 / P1, the cause is likely a worn part that needs replacing.
Other Carrier air conditioner codes
- Solid / 1 / 2Status light showing normal operation
- 16Lost communication with the Infinity control
- 25Model plug missing or wrong
- 31 / 84High-pressure switch tripped or locked out
- 32 / 83Low-pressure or discharge temperature trip
- 45Outdoor control board fault
- 46Brown-out: supply voltage too low
- 47No 230-volt power reaching the outdoor unit
- 53 / 55 / 56Outdoor air or coil sensor fault
- 71 / 72 / 81 / 82Compressor thermal cutout or lockout
- 73 / 74Contactor stuck closed or not closing
- E1Ductless indoor and outdoor units not talking
- ECRefrigerant leak detected
- E3 / F5Ductless fan speed out of range
- E4 / E5 / F1 / F2 / F3Ductless temperature sensor open or shorted
- P3Too cold outside to heat
- P5Multi-zone mode conflict
- CL / dFFilter reminder or defrost in progress
Last reviewed 2026-10-22. Codes and steps can vary by model; check your owner's manual.