grundfos magna1 pump not circulating, no central heating...

Anyone have any experience with the Grundfos pumps, specifically MAGNA1 40-60F?

The Grundfos Eye is showing two opposite red indicator lights flashing, which indicates alarm, the pump is stopped

Isolating and opening, the mechanism is turning freely, so I assume nothing clogging up the mechanism (impeller?). What looks a little odd is how there looks like 5mm of wear on the central mechanism (the rotor?) towards the end (see pic)

It's been in for 3 1/2 years, No central heating at the moment...

I should have said, when the heating is switched on, the green spinny circle light on the "grundfos eye" comes on briefly, before turning to the flashing red

After a lot of searching round and phone calls (not many places have it on the shelf) I picked up a Magna1 40-80F at a very good price and swapped the pumps over all is ok now. The 40-60F looks really undersized for the 70 Rads on the system compared to the 40-80... it's possible the smaller pump was jammed (I wasn't there when it was opened - they were not looking at the right thing) but it's been a long day of driving that will be for another day to look at