E4 appears on the display and the unit shuts down shortly after starting a cook cycle.

Safety first: Unplug the appliance and wait for all internal parts to cool. Heating components can remain hot even when the unit is off.

• Visual inspection: Remove the basket and look up at the heating element. Check for obvious breaks, warping, or burn marks on the coil.
• Check heater connections: Remove the rear or top cover (depending on model). Locate the two heater terminals and ensure the push‑on connectors are tight and not oxidized or burnt. Reseat any loose connectors.
• Test heater continuity: With a multimeter, measure resistance across the heater terminals. A typical element will show a finite resistance (often 10–40 ohms). Infinite resistance indicates a failed open element that must be replaced.
• Inspect wiring harness: Follow the heater wires back to the control board. Look for melted insulation or signs of arcing. Replace any damaged harness sections with high‑temperature wire.
• Relay/board fault: If the heater tests good but E4 persists and there is no voltage reaching the heater during operation, the heater relay or control PCB is likely faulty. Board replacement is usually required.