GE air conditioner shows E3 and may shut down cooling or fan operation intermittently

Safety: Unplug the unit. If it is a window unit, support it securely before removing any mounting hardware.

Procedure:

• Power cycle: Disconnect power for 5–10 minutes and restore. If E3 returns, proceed with inspection.
• Access condenser section: Remove the unit from the window or sleeve if necessary. Take off the outer cabinet shell (screws on sides/back). This exposes the condenser coil (the warm coil at the rear).
• Locate outdoor sensor: The condenser thermistor is usually clipped to the condenser coil or mounted near the compressor with two small wires leading to the control board.
• Inspect sensor and wiring: Check for broken insulation, corrosion, or a sensor that has come loose from the coil. Reattach with the original clip or metal tape if loose.
• Check connector: Follow the wires to the control board and ensure the plug is fully seated and clean. Reseat it.
• Test sensor: With a multimeter, measure resistance at room temperature and compare to GE specs. Replace the outdoor temperature sensor if readings are open, shorted, or far off spec.
• Board diagnosis: If a known-good sensor is installed and wiring is intact but E3 persists, replace the main control board.

Warning: Do not damage refrigerant lines or the compressor. Refrigerant work must be done by an EPA-certified technician.