Display shows E5 and the unit will not heat; fan may run but no temperature increase.

Safety first: Unplug the air fryer and allow it to cool completely. The heating element and surrounding metal can remain hot for a long time.

Step-by-step checks:

• Visual inspection of element: Remove the basket and pan. Look up at the heating element in the top of the cooking chamber. Check for visible breaks, burn spots, or sagging coils.
• Access heater terminals: Remove the top or rear cover (depending on model) to access the two terminals of the heating element. Inspect for burnt connectors or melted insulation on the wires.
• Continuity test (advanced): With the unit unplugged, use a multimeter to check resistance across the heating element terminals. A good element will show a finite resistance (often 10–40Ω). If it reads open (OL), the element is defective.
• Check thermal fuse: Many GoWISE USA air fryers include a non-resettable thermal fuse in series with the heater. Locate the small cylindrical fuse wrapped in heat-resistant sleeving near the element. Test for continuity; if open, it must be replaced with the exact temperature and current rating.
• Control board relay: If the element and fuse test good, but there is still no heat, the heater relay on the main control board may have failed. Look for signs of burning or pitting on the relay contacts (if visible).

When to stop: If you are not comfortable testing live circuits or replacing high-wattage components, contact a professional technician. Never bypass a thermal fuse for testing or operation.