Well, after 7 years of almost daily use, it appears that the pump has failed on my Andreja Premium espresso machine.
The machine uses a 52W, ULKA EAX5 vibe pump – and as it turns out, this is a fairly commonly used pump in espresso machines. I also found prices varied wildly. The dealer where I purchased the machine originally sells the replacement pump for $95. I found a replacement on Ebay for $39.99.
So, removed the casing from the machine and hooked the water supply back up, and this time I tested things out with the cover off. This allowed me to see the water flow. Everything worked fine. Maybe I kinked a hose as I put the machine back together?
I carefully put everything back together – making sure no hoses were kinked, and tested the machine again – everything was 100%. This morning, the timer kicked in and turned the machine on at 6:00 AM, and at 7:00, I pulled a double shot with no issues. I think that the shot was up there with some of the best that I’ve done!
Something I came across, that might be useful in future, is this page describing the process of repairing the ULKA pump itself – with lots of photos and additional comments from other readers. I still have the old pump just in case. They certainly aren’t that complex!