Luxaire AC shows E5; unit may not respond to thermostat commands or may shut down unexpectedly.

Safety: Turn off power to both indoor and outdoor units before touching any wiring.

• Inspect communication wiring: Locate the low‑voltage terminal strip on the Luxaire air handler and condenser. Verify the communication wires (often labeled C, Y, R, Data, etc. depending on model) are landed on the correct terminals and firmly tightened.
• Check for cable damage: Follow the thermostat/communication cable between units. Look for rodent damage, UV‑cracked insulation, or splices that have come loose. Replace damaged cable with the same gauge multi‑conductor thermostat wire.
• Verify thermostat connections: Confirm that R, C, Y, G, and O/B (if heat pump) are correctly wired at the thermostat and match the Luxaire wiring diagram on the air handler door.
• Power cycle both units: Turn off breakers for indoor and outdoor units for 5 minutes, then restore power. Some Luxaire systems will re‑establish communication and clear E5 automatically.
• If E5 persists: The indoor or outdoor control board may be defective. Replacement and re‑programming should be done by a qualified technician familiar with Luxaire controls.