Hi,
New to the group but have found posts and tips incredibly helpful over the last few years - thank you all.
I've a BES 920 which has been going OK for a few years. Started mis-behaving so it came time for a good service. I've replaced o-rings, the steam water pump and the solenoid.
First run with empty group-head went well, there didn't appear to be any issues. Pressure better than I've ever had, at 7.5 - 8 bar.
Then a run with coffee and the pressure went up to ~9 bar but there is no water at the group-head.

Any suggestions from the experts here?

Have you tried grinding coarser? You may have simply choked the machine with too fine a grind.

To clarify the run with "empty group head"?
-Did you have water flow? if not, suggests 3-way solenoid issues
-Did you have water flow but 8 bars at the pump? That suggests a blockage somewhere - there should be very low pressure when just flushing

Thanks @nunas and @nisb,
I'll try a coarser grind - seems like a good idea.

I did you have water flow but 8 bars at the pump with empty group-head in place. I'll try again and watch for water flow through the various pipes.
I was wondering if I need to adjust the OPV?