Onyx 22mm Brass Magnetic Filter with Valves ONYXFILTER

The Onyx 22mm brass magnetic filter with valves is an in-line central heating filter with a brass body and an internal magnet. It captures black iron oxide and other magnetic debris circulating in the system water before it reaches the boiler and heat emitters. The valves allow the filter to be isolated for servicing without draining the whole system.

• Radiators heating unevenly, with cold spots at the bottom of the panels
• Visible sludge or black iron oxide debris around the filter or in the system water
• Water weeping from the filter body or from the valve connections
• System pressure dropping and needing frequent top-ups
• The magnet no longer holding captured debris effectively

• Confirm the pipework at the intended installation point is 22mm
• Check there is enough clearance to fit and service the filter, including access to the valves
• Confirm the filter will be installed on the heating return in line with the manufacturer's instructions
• Check whether the system needs a chemical flush before the filter is fitted