Remote Controller Signal Receiving Error (Indoor Unit)

What does E4 mean?

The indoor controller board cannot receive any data normally from the remote controller board or from other indoor controller boards for 3 minutes, or cannot receive any signal from the remote controller for 3 minutes. Potential causes include contact failure or miswiring of the remote controller transmission wire, all remote controllers being set as 'sub', exceeding total wiring length (max 200m) or number of connected indoor units (max 16) or remote controllers (max 2), a defective transmitting/receiving circuit, or noise in the transmission wire.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Check remote controller wiring specifications: Total wiring length max 200m (do not use cable >= 0.75mm2), max 16 indoor units, max 2 remote controllers.

2. 4

   Diagnose remote controllers: If 'RC OK' is displayed, turn power off/on; if abnormal again, replace indoor controller board. If 'RC NG' is displayed, replace the remote controller. If 'RC E3' or 'ERC 00-06' is displayed, noise may be causing abnormality.

3. 5

   If the unit is not normal after replacing the indoor controller board in group control, the indoor controller board of address '0' may be abnormal.