Diagnosis
The machine is failing its automatic pump prime cycle. This is almost always an airlock in the internal water line or a weak water tank sensor connection.
How to Fix It
Remove and firmly re-seat the water tank. Ensure the magnetic sensor pad on the bottom of the tank and the contact in the base are clean and dry. Turn the machine off and on to restart the prime cycle.
If That Didn't Work
Manually prime the system: place a large cup under the group head and steam wand. Turn the steam dial to open, then press and hold the 'Hot Water' button for 10 seconds to purge air from the boiler lines.
Heads Up
Using the machine with an empty or improperly seated tank can damage the pump. Always check the tank is full and clicked fully into place.