What It Means
High-pressure switch tripped.
Carrier Air Conditioner
Carrier Air Conditioner Error Code 31
Troubleshooting guide for the Carrier Air Conditioner system fault 31.
Possible Causes
- Low outdoor airflow from dirty coil or fan issue.
- Refrigerant overcharge.
- Restriction in refrigerant circuit.
Not sure which one it is — or if it's none of these? Try ACLogics today.
Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
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Full Diagnosis
High Pressure Switch Open. High-pressure switch trip; can accumulate over multiple cycles.
All Recorded Causes
Check refrigerant charge level. Inspect outdoor fan operation and coil for airflow restrictions or debris. Verify refrigerant charge is within specification. Clean condenser coil if dirty.
Verify Before Replacing Parts
- Confirm the exact Carrier model family and air conditioners context before acting on a generic code description.
- Verify airflow first, then confirm operating pressures and temperature relationship before adjusting charge, since check refrigerant charge level.
- Look for restrictions, iced coils, or dirty heat-transfer surfaces that can mimic a charge problem, and separately confirm inspect outdoor fan operation and coil for airflow restrictions or debris.
- After the correction, run the system long enough to confirm the air conditioners fault does not return under normal load.
Still unsure about this fault?
ACLogics walks you through Carrier Air Conditioner diagnostics step-by-step — so you confirm the cause before swapping parts.
