It sounds like it locked up with calcium, it is too old to have the swollen rotor issue, that only occured in pumps made for a few weeks in April/May. Usually in this case the rotor has to be drilled out, you can try pulling really hard to extract it but they usually are broken in the process of getting them out. These pumps need to be cleaned every 6 months at a minimum and if the calcium or KH is very high or kalkwasser is being added near the pump they can lock up in 3 months or so. I would suggest sending it in but I must get the pump by August 17 to get it repaired before I leave for Germany.