Washer overfills or shows E04; water level too high or water continues to enter even when machine is off.

Safety first: Unplug the washer immediately and close the water taps to stop filling. If water is overflowing, manually bail out excess water.

Step-by-step checks:

• Check if valve is mechanically stuck: With the washer unplugged and taps open, observe if water still flows into the drum. If yes, the inlet valve is stuck open and must be replaced.
• Inspect pressure hose: Remove the top cover. Locate the thin rubber hose running from the bottom of the tub to the pressure sensor. Check for cracks, splits, or disconnections. Remove the hose and blow through it to ensure it is clear. Replace if brittle or damaged.
• Test the pressure sensor: With a multimeter, check the sensor according to the Grundig service manual (often a 3- or 4-wire analog or digital sensor). If readings are out of range or the sensor does not change output with applied pressure (gently blowing into the hose), replace the sensor.
• Inspect wiring and PCB: Ensure the pressure sensor connector is firmly seated on the main PCB and that there are no burnt tracks or components. If the inlet valve and sensor are good but E04 persists, the control board may be faulty and require replacement by a technician.