Air fryer displays E4 and will not heat or complete a cooking cycle.

Safety first: Unplug the air fryer. Heating components can retain heat; allow full cooling before touching.

Steps to address E4:

• 1. Visual inspection of the heater: Remove the basket and look up toward the top of the cooking cavity. Check the exposed heating element for breaks, heavy pitting, or burn marks.
• 2. Access heater connections: Remove the rear or top cover (depending on model) to access the heater terminals and wiring. Look for loose spade connectors, burnt insulation, or discoloration around the terminals.
• 3. Tighten or reseat connectors: If a heater terminal is loose, remove and clean the connector, then firmly reseat it. Replace any connector that is burnt or deformed.
• 4. Continuity test (advanced): With the unit unplugged, disconnect at least one heater lead and measure resistance across the heating element. A typical value is between 10–60 Ω. If the meter reads OL (open), the element is broken and must be replaced. If it reads near 0 Ω and you see evidence of arcing to the chassis, the element is shorted and must be replaced.
• 5. Inspect the control board heater relay: On the main PCB, locate the heater relay or triac. Look for cracked solder joints, burnt spots, or a melted relay case. A failed relay can also trigger E4.
• 6. Replace faulty parts: Replace the heating element assembly if open or shorted. If the heater is good but the relay is visibly damaged or does not click when the unit tries to heat, replace the control board.

Note: If you see any signs of arcing or melted plastic around the heater, discontinue use immediately and have the unit professionally inspected.