How to Fix / Troubleshooting

Safety first: Unplug before moving the machine. Hot water can cause burns.

E04 usually means the control board does not detect water flow.

Bleed air from system: Fill the water tank completely. Plug in, then run a hot water or rinse cycle (if available) without coffee. Start and stop the cycle a few times to purge air.
Check tank filter: Remove and clean any mesh filter or valve at the bottom of the water tank. Debris here can starve the pump.
Descale: Run a full descaling program to clear lime deposits from the flow meter and thermoblock.
Inspect hoses (if accessible): Look for pinched or sharply bent silicone hoses from the tank to the pump and from the pump to the thermoblock.
Persistent E04: The flow meter (small plastic wheel sensor in the water line) may be stuck or its Hall sensor defective. Replacement of the flow meter assembly is typically required.

Display shows E04 and the pump runs loudly but no water flows through the coffee outlet.

Possible Causes