System Diagnosis
Liquid line pressure sensor fault (open or shorted).
Trane | AC and Heat Pump
Error Code Red 12 Flashes
Troubleshooting guide for the Trane AC and Heat Pump system fault Red 12 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 the wiring to the pressure transducer.
- Replace the sensor if confirmed bad; a technician should verify system pressures and operation.
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