Multicooker displays E4 and does not start pressure cooking; may occur immediately after pressing Start.

Safety first: Ensure the cooker is completely depressurized and unplugged before inspection. Never attempt to open the lid under pressure.

Steps to check:

• Clean pressure pathways: Remove the steam release valve and anti-block shield (if fitted) from the lid. Clean all small holes and channels with a soft brush and warm soapy water. Rinse and dry thoroughly.
• Inspect the pressure sensor port: On many Siemens models, a small tube or channel from the lid or inner top plate leads to the pressure sensor. Ensure it is not clogged with starch or food residue.
• Check sensor connector (advanced): With the unit unplugged and top or bottom cover removed (depending on model), locate the pressure sensor module (often a small rectangular device with a hose or port). Confirm the connector is firmly seated on the PCB and that wires are not damaged.
• Visual inspection: Look for corrosion or moisture around the sensor. If the sensor housing is cracked or corroded, replacement is required.
• Reassemble and test: Refit all parts, ensuring the steam valve and anti-block shield are correctly installed. Run a water-only pressure test to confirm normal operation.

When to call a technician: If E4 persists after cleaning and reseating connectors, the pressure sensor or main PCB likely needs replacement by a qualified technician.