Washer overfills or shows E04 shortly after starting; may attempt to drain immediately

Safety first: Unplug the washer and turn off water supply. If the drum is overfilled, manually drain via the pump filter before proceeding.

Steps to check and address E04:

• Inspect the pressure hose: Remove the top cover. Locate the thin pressure hose running from the drum/air chamber to the pressure switch. Check for kinks, cracks, or disconnections.
• Clean the pressure chamber: At the drum side, the air chamber can clog with detergent residue. Carefully remove the hose and flush the chamber and hose with hot water to clear soap scum.
• Check the inlet valve: With water supply on and machine unplugged, see if water continues to trickle into the drum. If so, the inlet valve is mechanically stuck open and must be replaced.
• Test the pressure switch: With power disconnected, remove the pressure switch connector and test continuity while gently blowing into the pressure hose. The switch should click and change state. If not, replace the water level sensor/pressure switch.

When to call a technician: If hose, chamber, valve, and switch are all good, the control module may be misreading the signal and should be checked by a Siemens service engineer.