We have underfloor heating installed with heatmiser UH8-RF and Grundfos UPM3 Flex As pump and Honeywll 272848 motorized valve. It was working fine for nearly year and now it has started blowing surge fuse 5am 250v,(Fuse-2) in UH8-RF. Enire system is new and not sure why it is keep blowing surge fuse...
