Why does the espresso drip so slowly, or not at all, out of the portafilter in my espresso machine?
Check the following possibilities:
Is the portafilter fully inserted into the brew head?
Verify that the portafilter basket holes or brew head screen holes aren’t clogged.
Is coffee too finely ground, the portafilter basket too full, or the coffee tamped too hard?
Does the machine need priming?
Is there water in the tank?
Check to see if the steam button is engaged.