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.
How to clean a heating system?
Systems should be cleaned when commissioning a new system or installing a new boiler within an existing system. The purpose of cleaning and flushing is to remove mineral oil, harmful flux residues and installation debris which can cause corrosion. Cleaning existing systems removes magnetite (black iron oxide), haematite (red iron oxide) and limescale improving the circulation and reducing fuel wastage
