System Diagnosis
Low-pressure cut-out fault. (Code 79 on some controls.) The system’s low-pressure switch opened.
Trane | AC and Heat Pump
Error Code Red 7 Flashes
Troubleshooting guide for the Trane AC and Heat Pump system fault Red 7 Flashes.
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.
Potential Causes & Solutions
- Check that the air filter is clean and indoor airflow is not obstructed.
- If coils are iced, allow them to thaw.
- If the error continues after reset, there may be a refrigerant leak or bad pressure switch; contact a qualified technician.
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