Check that the tank is at least half full with water. If it's not, fill it up.
Insert an empty portafilter into the machine by placing it and turning it to the right.
Put a bowl underneath the portafilter.
Press and hold the two-cups button for at least one second, then release it.
Soon the pump will start and the water will begin to flow out of the portafilter.
This preheats the machine and warms the portafilter.
When the pump audibly stops, remove the portafilter and try it with a towel.