Display shows E5 and the unit shuts down or refuses to brew, sometimes after a loud pump noise.

Safety first: Unplug the coffee maker before inspection. Allow it to cool if it has been running repeatedly.

User checks:

• Fill and reseat reservoir: Ensure the reservoir is full and properly installed. Try a brew cycle with plain water.
• Descale: Run a 1:1 vinegar and water solution through the machine to clear scale from the pump and inlet line. Let the solution sit for 20 minutes if flow is weak, then run again.
• Avoid dry running: Never run the machine without water in the reservoir; this can trigger E5 and damage the pump.

If E5 continues:

• The vibration pump may be failing or the control board may be shutting it down due to overcurrent. Replacement of the pump or main control PCB is typically required and should be done by a technician.