High-pitched squealing or whistling noise when brewing or steaming.

Safety first: Unplug and allow the machine to cool before cleaning nozzles.

Steps:

• Clean nozzles: Remove the coffee outlet spout and steam wand tip (if present). Soak in hot water and clean with a fine brush or needle.
• Descale: Run a descaling cycle focusing on both coffee and steam circuits.
• Check pressure valve (advanced): Inspect the pressure relief valve for scale or damage. Replace if it does not open smoothly.