Indoor unit shows E6; unit may not start or may run briefly then stop; often associated with communication loss between indoor and outdoor units.

Safety first: Turn OFF the breaker before removing any covers. Incorrect wiring can cause electric shock or damage electronics.

• Step 1 – Inspect communication wiring: Open the indoor and outdoor terminal covers. Verify that the multi‑core communication cable is firmly connected and that terminal numbers (e.g., 1‑2‑3) match exactly between indoor and outdoor units. Tighten any loose screws.
• Step 2 – Check for damaged cable: Look along the cable route for cuts, rodent damage, or crushed sections. Replace the cable if any damage is visible.
• Step 3 – Confirm polarity and wiring order: Ensure that the same colored wire goes to the same terminal number on both ends. Incorrect polarity can cause E6.
• Step 4 – Power cycle: After correcting wiring, turn the breaker OFF for 5–10 minutes, then ON again and test operation.
• Step 5 – If E6 persists: Either the indoor or outdoor PCB may be defective. A technician should check communication signals with a meter and may need to replace the faulty board.