Air fryer beeps and shows E4; fan may run but heater does not engage.

Safety first: Unplug the Severin air fryer and wait for it to cool. Do not attempt to power it on while covers are removed.

• Visual inspection of heater: Remove the top or rear cover to access the heating element. Look for visible breaks, burn marks, or areas where the element has contacted metal parts.
• Check heater resistance: Disconnect the heater leads from the PCB. Measure resistance across the heating element with a multimeter. A very low resistance (near 0 Ω) or visible short to chassis indicates a defective element that must be replaced.
• Inspect wiring harness: Follow the high‑temperature wires from the heater to the control board. Look for melted insulation, pinched sections, or loose spade connectors. Repair or replace damaged wires with high‑temperature rated cable.
• Examine control PCB: Inspect the heater relay or triac area on the PCB for burn marks, cracked solder joints, or bulging components. If the relay contacts are welded or the triac is shorted, replace the main control PCB or the discrete component if you have soldering skills.
• Reassemble and test: After replacing any faulty parts, reassemble the housing fully before testing. Run a short cycle at low temperature to confirm normal operation.

Warning: Heater circuits carry mains voltage. If you are not experienced with electrical repairs, seek professional service.