What the code means
PC 43: Outdoor compressor lack phase protection
The Carrier 38MURA error display indicates outdoor compressor lack-phase protection.
Troubleshooting code
Carrier Crossover 47000 BTU Up to 15.8 SEER2 Heat Pump Condensing Unit R-410A (208/230-1) PC 43 troubleshooting
Outdoor compressor lack phase protection. Use this page to document the issue and prepare for service. GreenFlow should handle diagnosis for electrical, refrigerant, lockout, or recurring conditions.
Safe checks before calling
- Confirm the thermostat or controller is powered, set correctly, and calling for heating or cooling.
- Check filters, return-air grilles, supply registers, and visible airflow paths that can be reached without opening equipment panels.
- Look for visible outdoor-unit or rooftop obstructions, debris, snow, ice, or blocked clearances from a safe location only.
- Take photos of the displayed code or LED pattern, equipment nameplate, thermostat or controller, and the surrounding equipment area before scheduling service.
When to stop and call GreenFlow
Call GreenFlow if the code repeats, the unit is locked out, heating or cooling is not restored, there is flame, gas, electrical, refrigerant, pressure, compressor, fan-motor, rooftop-access, or warranty-related concern, or any troubleshooting would require opening equipment panels.
Share the visible code, model and serial number if available, photos, current symptoms, and whether the issue affects heating, cooling, or both.
PC 43 questions
What does PC 43 mean on a Carrier Crossover 47000 BTU Up to 15.8 SEER2 Heat Pump Condensing Unit R-410A (208/230-1)?
The Carrier 38MURA error display indicates outdoor compressor lack-phase protection.
What should I safely check before scheduling service?
Confirm thermostat or controller status, check filters and visible airflow restrictions, look for outdoor-unit or rooftop obstructions from a safe location, and take photos of the code or LED pattern and nameplate. Do not open electrical, gas, refrigerant, or rooftop control compartments.
When should GreenFlow handle this code?
Call GreenFlow if the code repeats, the unit is locked out, heating or cooling is not restored, there is flame, gas, electrical, refrigerant, pressure, compressor, fan-motor, rooftop-access, or warranty-related concern, or any troubleshooting would require opening equipment panels.
Need help with this code?
GreenFlow can review the code, photos, equipment access, and symptoms before scheduling the right next step.
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