E03 is displayed and no water flows through the coffee spout even though the pump can be heard briefly.

Safety first: Unplug the machine and allow it to cool.

• Check water tank and filter: Remove and refill the tank with fresh water. If your Ariete model uses an internal water filter cartridge, remove it temporarily and test without it in case it is clogged.
• Run a descaling cycle: Fill the tank with a descaling solution approved for coffee machines (follow Ariete instructions). Start a descaling program or run repeated hot water cycles to dissolve limescale that may be blocking the flow meter.
• Inspect hoses (if accessible): On some models you can see the clear silicone hoses from the tank to the pump. Look for kinks or air locks. Straighten any bends and gently tap the hose to move trapped air.
• Reset error: After descaling and checking hoses, unplug the machine for 5 minutes, then reconnect and test.
• If E03 persists: The flow meter assembly may need to be removed, cleaned, or replaced. This involves opening the housing and disconnecting hoses; contact a professional technician to avoid leaks or electrical hazards.