Magnetic dirt removal in hydronic heating and cooling systems is a hot topic these days. Check out this short video, showing how the Caleffi 5465 Series DIRTMAG works.
See how Hurst Mechanical is keeping boilers clean in Belmont, Michigan in this case study.
To learn more about magnetic dirt removal technology and magnetite, that nasty "boiler ink" that experienced hydronic service technicians know well, check out Caleffi's May 2015 Magnetic Separation in Commercial Hydronic Systems Coffee with Caleffi webinar.