E9 error code appears and the unit stops heating intermittently.

Safety first: Unplug the air fryer and wait for it to cool. Internal components are connected to mains voltage; do not touch live circuits.

• Access main PCB: Remove the rear or bottom cover to expose the main control PCB. Identify the heater relay or triac (often a rectangular relay or a triac mounted with a heatsink).
• Inspect for heat damage: Look for discoloration, melted plastic, or burnt PCB traces around the relay or triac. If present, the board should be replaced.
• Check solder joints: Examine the underside of the PCB for cracked or dull solder joints on the relay pins. Reflowing solder should only be done by someone experienced with electronics.
• Functional test: If you are qualified, you can test whether the relay clicks when the unit calls for heat. Lack of clicking or intermittent operation indicates a failing relay or driver circuit.
• Replace main PCB: For most users, the practical repair is to replace the entire main control PCB with a compatible Hisense part rather than attempting component-level repair.