How do I install my Flair 58 portafilter, and how can I tell when it is properly locked in?

My portafilter doesn't feel fully engaged, or I cannot tell.

To install: Start with the portafilter around the 6 o'clock position, and rotate the handle of the portafilter to around 4 o'clock. Do not over-tighten: You will risk damage to the brew head base. It needs only to be snug!

When you are locked in, you won't be able to see the red gasket of the brew head from below. Another tell-tale sign that you are properly locked in: If you are not experiencing a clear water leak between the portafilter and brew head walls, it is sealing as designed.