Fernox Cleaner F3 should ideally circulate through the system for at least one hour, or up to a week. Afterward, it should be drained, and the system flushed and cleaned before adding Fernox Protector F1 or Protector + Filter Fluid, together with a Fernox TF1 Filter, to protect the system from further corrosion and scale formation.
Why do I need to test system water?
A core requirement under BS 7593:2019 is that central heating systems are tested annually, to help maintain system health and to identify and rectify any issues before they cause damage to the system. The Benchmark Commissioning Checklist further supports this practice to evidence the correct servicing and installation of boilers. The onsite Express Inhibitor Test makes compliance with these industry



















