E4 error appears when starting a pressure program; cooker does not build pressure.

Safety: Ensure the cooker is unplugged and fully depressurized before opening or servicing.

Steps:

• Check lid closure: Make sure the lid is aligned with the markings and fully locked. On Russell Hobbs pressure multicookers, the lid must engage the locking pin and microswitch.
• Inspect lid switch: With the unit unplugged, open and close the lid while listening for a faint click from the lid microswitch. If there is no click or the lid feels loose, the lid lock switch assembly may be misaligned or faulty.
• Clean pressure sensor path: Remove the steam release valve and anti‑block shield (if fitted). Clean any food residue from the valve, lid channels, and the small pressure port leading to the sensor. Use a soft brush and warm soapy water, then dry thoroughly.
• Check silicone hose (if present): Some models use a small silicone tube from the lid port to a pressure sensor on the PCB. Inspect for cracks, blockages, or disconnection.
• Test again: Reassemble all parts correctly, ensuring the float valve moves freely. Run a water‑only pressure test. If E4 persists, the pressure sensor or control PCB likely needs replacement.

Note: Replacing the lid switch or pressure sensor requires opening the housing; if unsure, contact a technician.