E4 appears during cooking or immediately after starting, and the cooker stops heating.

Safety first: Unplug the unit and allow it to cool completely before inspecting the heating area.

• Inspect heating plate: Remove the inner pot and check the aluminium heating plate for burnt residue, dents, or foreign objects. Clean gently with a soft cloth; do not scratch the surface.
• Check inner pot flatness: Place the pot on a flat countertop and see if it rocks. A warped pot can cause hot spots and trigger E4. Replace the pot if it is not flat.
• Ensure ventilation: Confirm that the cooker is used on a hard, heat-resistant surface with at least several centimetres of clearance around it so heat can dissipate.
• Test with water only: After cooling, fill the pot with 1–2 litres of water and run a basic program. If E4 still appears, internal overheat protection components may be failing.
• When to replace: Persistent E4 with a good pot and clean plate suggests a faulty thermal fuse/thermostat or heating element. These require disassembly of the base and should be serviced by a professional.