E4 appears on the display and the cooker will not start or stops mid‑cycle, often when using pressure or high‑heat modes.

Safety first: If the cooker is under pressure, do not force the lid open. Unplug the unit and allow pressure to drop naturally or use the manual steam release according to the user manual.

• Check lid lock: Open and close the lid several times, ensuring it clicks firmly into the locked position. On models with a mechanical lock pin, verify that the pin moves freely.
• Clean steam valve: Remove the steam release valve and anti‑block shield (if fitted). Wash them thoroughly to remove food particles or starch buildup, then reinstall correctly.
• Inspect sealing ring: Remove the silicone sealing ring from the lid. Check for cracks, deformation, or food stuck in the groove. Clean and reinstall, or replace if damaged.
• Test without food: Add 1–2 cups of water to the inner pot, close the lid, and run a short pressure program. If E4 reappears, the pressure sensor or lid switch may be faulty.
• Service pressure sensor (technician): Access the top cover from inside the lid or upper housing and test/replace the pressure sensor module or lid microswitch as specified for the Binatone model.