Oster air fryer shows E5 on the display and will not heat, though the fan may still run.

Safety: Unplug the appliance before removing any covers. Heating components can retain heat for several minutes after use.

E5 typically points to a problem in the heating element circuit.

• Visual inspection: Remove the basket and look up at the heating element. Check for visible breaks, sagging coils, or burn spots.
• Access heater terminals: Remove the rear/bottom cover to access the back of the heating element. Inspect the spade connectors for discoloration, melting, or looseness.
• Tighten or repair connections: If connectors are loose, remove and clean the terminals, then crimp them tighter or replace with high-temperature-rated connectors.
• Test the element: Disconnect at least one heater lead and measure resistance across the element with a multimeter. A typical air fryer element may read between 10–40 Ω. An open circuit (OL) indicates a failed element.
• Replace heating element: If open or visibly damaged, remove the mounting screws or brackets holding the element, disconnect wiring, and install an Oster-compatible heating element assembly. Ensure proper routing of wires away from hot surfaces.
• Check control board relay: If the element tests good but E5 remains and there is no voltage to the element during a cook cycle, the heater relay on the main control board may be defective. Replace the main control board if you are experienced with appliance electronics.