Iron oxide sludge builds up within your hydronic heating panels will reduce the amount of heat energy output from your panels, which in turn means the boiler will have to run longer to raise the room temperature. The longer it runs the more energy it consumes and the higher your running costs.
The thermal image of the radiator panel is showing an inefficient panel. The blue area means it’s cold and should be hot. The only reason it is cold is that it will be full of sludge, the image should show an even orange over the whole panel.
A Hydronic Boiler Magnetic Filter reduces your running costs by ensuring it’s running at full efficiency with no sludge.