E1 n 28 (FJM Indoor) — Heat exchanger in temperature sensor detached

What does E1 n 28 mean?

The FJM indoor unit displays E1 n 28, indicating that the heat exchanger 'in' temperature sensor has become disconnected or detached from its position. This prevents accurate temperature readings.

• Loose sensor connection or mounting
• Damaged sensor wire

Click steps to track your progress.

1. 1

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

2. 2

   Locate the heat exchanger 'in' sensor on the indoor coil and ensure it is firmly connected and properly seated.

3. 3

   Check the sensor's wiring for any signs of damage or disconnections.

4. 4

   Restore power and check if the error clears. If not, contact a qualified technician.