22mm Magnetic Filter For Water Underfloor Heating Systems Supplying the UK since 2001 with the luxury of Underfloor Heating into Every Room of your Home The magnetic system filter is a uniquely versatile central heating filter that has been designed to combat the problems caused by magnetic system sludge and non-ferrous debris. The unique design means that it can be fitted in almost limitless orientations to suit any installation. Featuring a high power, bi-directional 11,000 gauss magnet, a stainless steel mesh filter and a large bore drain plug means that servicing the filter is both quick and simple.