I can hear the pump pumping and water comes out of the wand so the pump is clearly working but nothing comes out of the head. I have checked the solenoid and the last chance for this expensive machine is cleaning out coffee or limescale in the system. I took the head screen above the basket out and it is completely blocked as are the various holes in the piece above the screen. When I stuck some pins in the channels I did manage to get some drips out of the head. But there is no real relationship between the pumping and the drips.
What I was wondering was which cleaners will burn through all this crud. To me the citrus ones all seem to be the same, none seem to be of any greater strength than others and I am not sure whether they are designed to dissolve the coffee or clean out limescale in the boiler. Whenever i have tried them in the past I have always found undissolved crud under the screen after use and what has come through has never seemed particularly dirty to me??
Lastly is there a balance to be drawn between trying to push cleaner through clogged pipes and pumping so much that there is a risk of blowing the pipes/pump/electrics?