F4 - Discharge Temperature Sensor Error

What does F4 mean?

This error points to a malfunction in the discharge temperature sensor. The system is unable to get accurate temperature readings from this sensor, leading to a shutdown. The ODU main board LED will display this code.

• Poor contact between the temperature sensor and the main board terminal
• Temperature sensor is abnormal
• Detecting circuit is abnormal

Click steps to track your progress.

1. 1

   Check if the discharge temperature sensor is correctly inserted into the socket on the main board.

2. 2

   Inspect the terminal connection between the main board and the sensor for looseness or foreign objects. Tighten or clean if necessary.

3. 3

   Disconnect the sensor and measure its resistance (refer to Appendix 1 for temperature-resistance relation).

4. 4

   Replace the temperature sensor if it is found to be abnormal.

5. 5

   Inspect the detecting circuit for any abnormalities.

6. 6

   Replace the outdoor main board if the problem persists.