1. Fernox 58232 F4 Express Central Heating Leak Sealer 265ml

    Model: 58232
    Availability: same day dispatch Same day dispatch if ordered before 1:00 pm
    Price:   £21.99

Fernox F4 Express Leak Sealer F4 is used throughout domestic heating systems for sealing small inaccessible leaks. Quick and convenient solution which works in just 30 seconds - simple to use without any mess. Protects against corrosion and limescale, and can protects up to 10 radiators. Maintains system efficiency and extends boiler life. 


  • Quick and convenient – doses in 30 seconds
  • Simple to use with no mess
  • Added via a radiator adapter or filling loop supplied
  • Saves time and money on draining down and repairing
  • Seeks out and seals most weeps and leaks
  • 100% recyclable can
  • Non-toxic, environmentally friendly formulation