Fernox F4 Central Heating Leak Sealer (LSI) 500ml

500ml Fernox F4 central heating leak sealer (LSI).

• Ideal for reducing pressure loss from sealed central heating systems.
• Seals most weeps and small, internal, inaccessible leaks.
• Saves time and money on draining down and repairing.
• Does not cause blockages of pump, air vents etc.

Compatible with all metals and materials commonly used in central heating systems.

Product Uses:

• Leak Sealer F4 works best in warm / hot circulating water and once evenly dispersed will usually be effective within 1 - 24 hours.
• The sealing efficiency of Leak Sealer F4 has been intentionally limited to prevent blockage of safety devices, pumps, etc.
• For long term protection against corrosion the system should also be treated with a Fernox Protector F1.