Multicooker shows E4 and refuses to start pressure or high-temperature programs.

Safety first: Disconnect power and allow the cooker to cool. Never add cold water to a very hot dry pot; let it cool first to avoid warping.

Step-by-step checks:

• 1. Confirm pot and contents: Ensure the original Saturn inner pot is installed and contains enough liquid for the selected program (usually at least the minimum level mark).
• 2. Clean contact surfaces: Remove the pot and clean both the bottom of the pot and the heating plate. Remove any carbonized food that can cause hot spots.
• 3. Reset thermal protection: Some Saturn multicookers have an internal manual-reset thermostat on the heating plate. With the unit unplugged and bottom cover removed, look for a small round thermostat with a button. If present, press gently to reset.
• 4. Inspect thermal fuse: Locate the thermal cutoff (small cylindrical component in heat-shrink tubing attached to the heater wiring). If it appears burnt or open (requires meter to test), it must be replaced with the same temperature and current rating.
• 5. Test with water: After cleaning and any reset, add water to the pot and run a low-temperature program. If E4 no longer appears, the issue was likely dry-boil protection. If E4 persists immediately, the thermostat or sensor circuit may be faulty.

Note: Replacing thermal cutoffs and thermostats involves working on mains wiring. If you are not trained, contact a professional technician.