Coffee Appreciation

My steamer wand seems to have stopped working. I only descaled about a month ago, and did a really through job then, so I'm wondering what the problem could be.

Normally once I've pulled a shot and pressed the steam button, the machine starts re-heating and steam starts coming out of the showerhead, which is generally when I start steaming. Now that doesn't seem to be happening at all. It has happened intermittently in the past, but now it doesn't seem to be working at all...

I don't recall ever having steam exit the shower screen. But then I usually leave the portafilter in place when steaming. Is there any steam/water coming from the wand at all?