The coffee has an acid taste
Try this solution
After descaling, rinse the appliance as described in descaling guide
Potential cause:
Inadequate rinsing after descaling.
Do you need descaler? Delonghi's EcoDecalk has been specifically designed with your machine in mind. Using this descaler regularly will prolong the lifespan of your machine and keep it running at optimal performance.
De'Longhi Coffee Machine Descaler EcoDecalk 500ml Best Value Pack (delonghi.com)
1. Before descaling
Important!
Before use, read the instructions and the labelling on the descaler pack.
You should use De'Longhi descaler only. Using unsuitable descaler and/or performing descaling incorrectly may result in faults not covered by the manufacturer's guarantee.
2. Fill the tank with the descaler solution
3. Dilute the descaler solution by filling the tank with water to the level specified on the descaler pack
4. Press the ON/OFF button
5. Make sure the filter holder is not attached and position a recipient under the hot water spout and boiler outlet
6. Wait until the OK light comes on
7. Turn the mode selector dial to the following position
and deliver around 1/4 of the solution in the tank.
8. At intervals, turn the steam dial to the following position:
and deliver water from the cappuccino maker.
Then turn the dial to the I position to stop the flow and let the solution work for 5 minutes.
Repeat the above mentioned process 3 more times until the tank is empty.
9. Rinse the water tank and fill it to MAX with clean water (without descaler)
10. Turn the mode selector dial to the following position
and deliver water until the tank is empty.
11. Rinse the water tank once more and fill it to MAX with clean water (without descaler)
12. Turn the mode selector dial to the following position once more
and deliver water until the tank is empty.
The machine is now ready for use.