Fernox F4 Express Internal Leak Sealer, 400 ml

Fernox Leak Sealer F4 Express is an internal central heating leak sealer designed to locate and seal small, inaccessible leaks and weeps that can cause system pressure loss.

The 400 ml pressure pack doses a system in less than 30 seconds without requiring a complete drain-down. The supplied universal applicator set allows dosing through a radiator air vent, filling loop or Fernox TF1 system filter.

Key features

• Seals small inaccessible internal leaks and microscopic weeps
• Effective within approximately 1 to 24 hours after application
• Doses in under 30 seconds without draining the system
• Designed not to block pumps, air vents, heat exchangers or other vulnerable components
• Compressed-air propellant is non-flammable and kept separate from the active product
• Universal applicator set included
• Suitable for combination boilers and other pressurised heating systems

System capacity

• Treats up to 130 litres of system water
• Suitable for systems with up to 16 radiators
• Treats up to 250 m² of underfloor heating

Specifications

• Brand: Fernox
• Product code: 62422
• Volume: 400 ml
• Dimensions: 218 x 66 x 95 mm
• Packaged weight: approximately 0.53 kg
• Barcode: 5014551624221

For internal central heating systems only. Follow the manufacturer's dosing and safety instructions. This product is intended for small internal leaks and weeps, not major pipe or component failures. Potable-water chemicals must be used in single-feed indirect cylinders such as Primatic systems.