DavecUK
To answer your questions: no the pump does not run if I unplug the wire to the fill sensor and yes the pump is still hot even with the service boiler off.
I had already emailed Paolo with M&V at the same time I posted in this forum. He said that the sound in the video is not the pump and said the pump might be frozen from being direct plumbed and sitting so long without use by the previous owner.
He told me to remove the pump and open it to free up the gears/magnet.
I was able to remove and disassemble the pump. I spun the two gears and they moved freely. I removed the magnet from the shaft and reinstalled. The magnet was also able to spin freely by hand.
I reassembled everything and reinstalled the pump. I turned on the machine and after two minutes, I received the same error message and red screen (“FillingUp Time-out”)
The pump is still very hot to the touch (this is before either of the boilers even begin to heat up)- the heat is originating from the square magnetic portion of the pump motor.
Do I have a bad magnet?