A magnetic filter is a device that helps collect the sludge that can build up in a central heating system.
Much of the sludge is made up of rust particles that have corroded and come away from inside pipes or radiators. A magnetic filter is made up of a giant magnet that attracts these particles and then filters them out of the system. This helps prevent blockages and keeps the water flowing through the central heating system.
Why would my heating system need a magnetic filter?
The iron and steel components in central heating systems are vulnerable to corrosion and rusting. This produces a sludge which can block different parts of the system, principally the boiler heat exchanger, pump or the radiators.
Old, cast iron pipes were usually a few centimetres in diameter but more new pipework tends to be narrower, making blockages even more likely.