Error 71 (7 Green, 1 Red Flash) — Discharge thermistor error

What does 71 mean?

The hydraulic unit's green LED flashes seven times and the red LED flashes once. This indicates an issue with the discharge thermistor, which measures the temperature of the refrigerant discharged from the compressor.

• Faulty discharge thermistor.
• Loose or damaged wiring connected to the thermistor.
• Incorrect thermistor reading due to system operating conditions.

Click steps to track your progress.

1. 1

   Perform a full power reset of the heat pump system by turning off the main breaker for 60 seconds and then turning it back on.

2. 2

   Ensure the outdoor unit is not obstructed, allowing proper airflow around components.

3. 3

   Check the ambient temperature; extreme conditions can sometimes trigger sensor-related errors.

4. 4

   If accessible (with power off), inspect the thermistor connections for any visible damage or looseness.

5. 5

   If the error continues, contact a qualified technician to test or replace the discharge thermistor.