Air fryer powers on but quickly shows E4 and will not heat.

Safety first: Unplug from mains. Wait until the unit is completely cool. Opening the case may void warranty; if under warranty, contact Salter support.

• Confirm no simple reset: Some models have a manual reset thermostat accessible through a small hole on the back or bottom. Check the user manual; if present, press gently with a non‑conductive tool to reset.
• Access heater assembly: Remove the outer housing screws and carefully lift the shell to expose the top heater and fan assembly. Note wire positions or take photos for reference.
• Test thermal fuse: Locate the small cylindrical or capsule‑shaped thermal fuse attached to the heater bracket. Using a multimeter, check for continuity. If open, it must be replaced; it cannot be reset.
• Inspect bimetal thermostat: If your model uses a bimetal thermostat in series with the heater, test for continuity at room temperature. If open and not resettable, replace it with the same temperature rating.
• Check heater wiring: Inspect all spade terminals and high‑temperature wires for burning or loose connections. Tighten or replace any damaged connectors.
• Clean to prevent recurrence: Before reassembly, clean heavy grease from the heater and surrounding metal to improve heat dissipation.
• Reassemble and test: After replacing the thermal fuse/thermostat, reassemble the housing, ensuring no wires are pinched. Test at a moderate temperature and monitor for normal cycling.