Safety: Disconnect power and close water taps.

Inspect pressure hose: Remove the top cover. Locate the pressure switch (round device with small hose). Check the hose for splits, kinks, or blockages. Blow gently through it (disconnected) to ensure it is clear.
Clean air chamber: At the tub end, the hose connects to an air chamber. Detach and clean out soap residue or sludge that can trap air and cause false readings.
Test the pressure switch: With a multimeter, check continuity across the switch terminals while gently blowing into the pressure port. Contacts should change state as pressure increases. If not, replace the switch.
Check inlet valve: Turn water taps off and run a cycle. If water still enters, the inlet valve is mechanically stuck open and must be replaced.
Inspect wiring: Verify the harness from pressure switch to PCB is intact and firmly connected.

Persistent E04 after these checks usually indicates a defective pressure switch or control board; replace the switch first as it is more common.

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

Possible Causes