I have a 2010 La Cimbali M21 Junior which I have owned since new.

Over the weekend it malfunctioned and there is no group head pressure. When I press the "on" button, there is a click but no resultant pump noise or water flow. I expect it is either the solenoid (hopefully) or the pump. Does anyone have any ideas what the problem may be and if my guess is likely correct, how best to determine whether it is the solenoid or pump?

By way of back ground its alway been run with rainwater so no scale bulid-up. It does get back-flushed, but I have to admit probably not regularly enough.

Thanks