LG air fryer shows E4 and will not start a cooking cycle.

Safety first: Disconnect power and wait for the unit to cool. Heating components can retain heat.

Steps to troubleshoot E4:

• Visual inspection: Remove the rear or top cover to access the heating element assembly. Look for broken coils, burn marks, or discolored terminals.
• Check connections: Ensure all spade connectors on the heater are tight. Gently tug each connector; if loose, remove, clean the terminal, and crimp the connector for a snug fit.
• Test the heater: Disconnect at least one heater lead and measure resistance across the element with a multimeter. A typical air fryer heater may read between 10–60 Ω. If it reads OL (open), the element is failed.
• Inspect wiring: Follow the heater wires back to the main PCB. Look for burnt insulation or broken conductors. Replace any damaged wiring with high-temperature rated wire of the same gauge.
• Replace the heater: If the element is open or visibly damaged, replace it with an LG-compatible heating element assembly. Transfer any brackets or shields from the old unit.

Note: If the heater tests good but E4 persists, the relay or triac on the main control board may be defective and require professional service.