Non-defined error code

What does EF mean?

This code appears when an unrecognized or non-defined error code is received by the system. It often points to communication anomalies, severe noise interference, an incompatible outdoor unit (not an inverter model), or an incorrect remote controller model. This issue prevents the system from accurately diagnosing problems and may indicate fundamental compatibility or communication failures.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Verify that the outdoor unit is an inverter model; replace if necessary.

2. 4

   Check the remote controller model (e.g., if PAR-S01A, replace with an MA remote controller).

3. 5

   If the abnormality persists, replace either the indoor controller board or the outdoor controller circuit board.