Why is my espresso only dripping or not flowing at all?

The most common causes are coffee ground too finely, too much coffee in the filter basket, or coffee tamped too firmly. Try using a slightly coarser grind, lowering the coffee dose, and tamping with 30–40 lbs (15–20 kg) of pressure. Also check that the water tank is full and properly inserted, the filter basket is not blocked, and that the machine does not need descaling. (Page 18)