E4 error appears shortly after starting a program; cooker may overheat or shut down.

Safety first: Unplug the unit and allow it to cool completely before touching the heating plate.

• Verify pot placement: Ensure the original Lagostina inner pot is correctly seated on the heating plate. Do not operate the cooker without the pot.
• Check food and liquid level: Confirm there is sufficient liquid according to the recipe and manual. Running the cooker nearly dry can trigger E4.
• Clean heating plate: Remove the pot and gently clean the heating plate and center sensor area with a soft cloth. Remove any burnt food or sugar that may cause hot spots.
• Inspect bottom for discoloration: If the plate is heavily discolored or warped, overheating may have damaged the thermal protection components.
• Reset thermal cut-out (if manual type): Some Lagostina models have a manual-reset thermostat on the underside. With the bottom cover removed (unplugged), look for a small round thermostat with a reset button. Press gently to reset.
• Test again: Reassemble, add proper liquid, and run a short program. If E4 returns quickly, the thermal fuse, thermostat, or sensor may need replacement.

Persistent E4 after proper use indicates a failing safety component; seek professional service.