E1 n 23 (FJM Indoor) — Heat exchanger out temperature sensor error

What does E1 n 23 mean?

The FJM indoor unit displays E1 n 23, indicating an open or short circuit in the heat exchanger 'out' temperature sensor. This sensor monitors the refrigerant temperature exiting the indoor coil.

• Faulty heat exchanger 'out' sensor
• Loose or damaged sensor wiring
• Issue with the indoor unit's PCB

Click steps to track your progress.

1. 1

   Turn off the power to the FJM indoor unit at the circuit breaker.

2. 2

   Visually inspect the heat exchanger 'out' sensor for damage and check its wiring connection to the indoor unit's PCB.

3. 3

   Ensure the sensor is properly positioned on the heat exchanger coil.

4. 4

   Restore power. If the error persists, contact a qualified technician to test or replace the sensor or PCB.