Remote Controller Signal Receiving Error (Indoor Unit)
Mitsubishi Electric · PUZ-HA30/36NHA4 Outdoor 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.
Common Causes
- Indoor unit fails to receive signals from the remote controller.
- Damaged or disconnected wiring between remote controller and indoor unit.
- Faulty indoor unit communication interface.
- Interference on the remote controller signal.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Check for disconnection or looseness of the indoor unit or remote controller transmission wire.
- 2
Set one of the remote controllers as 'main'.
- 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.
- 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.
- 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.