What It Means
Duplicate or redundant outdoor temperature sensor detected.
Trane AC & Heat Pump
Trane AC & Heat Pump Error Code Red 15 Flashes
Troubleshooting guide for the Trane AC & Heat Pump system fault Red 15 Flashes.
ACLogics Fix Trane code Red 15 Flashes See how ACLogics handles it → Fix Red 15 Flashes step-by-step
Possible Causes
- Redundant second outdoor sensor installed.
- Transient control sensing error.
- Control board detection fault.
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
Duplicate outdoor temp sensor detected.
All Recorded Causes
Remove or disconnect any redundant outdoor sensor if two are installed. If only one sensor exists, try resetting power; continued errors may require technician support.
Verify Before Replacing Parts
- Confirm the exact Trane model family and ac and heat pump context before acting on a generic code description.
- Verify the sensor or thermistor reading against the expected range for the current operating condition, keeping in mind that remove or disconnect any redundant outdoor sensor if two are installed.
- Check the sensor harness and board connection before condemning the sensor itself; on Trane units this is also where you'd confirm if only one sensor exists, try resetting power; continued errors may require technician su….
- After the correction, run the system long enough to confirm the ac and heat pump fault does not return under normal load.
Not sure which system this Trane code is on?
ACLogics has guided diagnostics for 36 Trane fault codes and asks the right questions to narrow it down.
