Yes, all Fernox internal leak sealers, such as Fernox Leak Sealer F4, are safe for use with combination and other low water content boilers.
They will not block valves or vents. Leak Sealer F4 Express is recommended for all pressurised systems as this can be added in 30 seconds via a radiator, filling loop or Fernox TF1 Filter, without the need to drain the system.
Citrate action is a term used to describe the powerful chelating effect that the citrate ion has on metal ions. This strong binding effect means that corrosion debris is lifted and transported out of the system during a system clean.
One bottle of Fernox Protector F1 or Protector + Filter Fluid will treat a typical system of ten single panel radiators – double panel radiators, count as two radiators. If the calculated dose rate is in between pack sizes, dose to the higher figure.
No, overdosing is not detrimental to the system. It is important to ensure that sufficient Protector is present in the system. There is a test kit and a postal testing service to check the Protector concentration. Refer to Protector Test Kit product data sheet for further guidance.
