Hi I have a polypipe multizone underfloor heating system (Gas) that stopped working a few weeks ago. It had been making some screeching noises and my hunch in that the Grundfos pump has died as the screeching has stopped - along with the heating! I may be wrong of course. The LED's on the side of the pump are not lit. Pics of control units attached. Hot water and radiators are fine. Its just the underfloor that has stopped. I took out the central pump screw and the spindle is turning freely so I don't think its blocked. It's cool to the touch also so I'm wondering of its a fuse ? Any help would be appreciated.