Description

Leak Sealer F4 is suitable to be used throughout a central heating system to seal small leaks and weeps which may cause pressure loss and boiler breakdown. Once dispersed within the system it will be effective 1-24 hours after application. The unique sealing efficiency of this proven product has been specifically developed to prevent blockages or restrictions within the boiler or vulnerable system components such as pumps and safety devices.

  • Quick and convenient – doses in 30 seconds
  • Simple to use with no mess
  • Added via a radiator adapter or filling loop supplied
  • Non-toxic, environmentally friendly formulation
  • 100% recyclable can
  • Seeks out and seals most weeps and leaks
  • Saves time and money on draining down and repairing
  • Does not cause blockages of pumps, air vents, etc
  • Compatible with all Fernox Protectors

Application and Dosage

One aerosol (265ml) will protect an average sized system (100 litres or up to ten single radiators) and is added via a radiator or filling loop. Fernox Leak Sealer F4 Express can be dispensed directly into a radiator air vent or system filling loop using the appropriate special adapter supplied with the product. The whole process takes less than two minutes. In single feed indirect cylinder, e.g. 'Primatic' or similar, potable water chemicals must be used.

Physical Properties


Colour: White
Form: Viscous liquid
Odour: Faint
PH: 5.0 - 7.0
SG: 1.0 @ 20°C

Packaging, Handling and Storage

Fernox Leak Sealer F4 Express is supplied in 265 ml aerosol cans with a universal applicator set. Fernox Leak Sealer F4 Express is classified as non-hazardous, but as with all chemicals: Keep out of reach of children. Do not mix with other chemicals. Do not take internally. In case of contact with eyes or skin, rinse immediately with plenty of water.

Please contact the supplier to check availability of stock