Fix leaks and boost your central heating system with Fernox Leak Sealer F4, the top choice for sealing small, hard-to-reach leaks and weeps. Prevent pressure loss and boiler breakdowns without draining your system, ensuring efficiency and longevity.

Optimize your heating with this industry-leading internal leak sealer, designed for quick, reliable repairs:

• Fast Leak Repair: Seals pinhole leaks and weeps in 1-24 hours, restoring system pressure and preventing boiler issues.
• Advanced Polymer Technology: Targets oxygen ingress, forming a robust polymer seal for lasting leak protection.
• No Drain-Down Needed: Saves time by sealing leaks internally, avoiding costly system drainage.
• Safe for All Components: Proven to avoid blockages in boilers, pumps, and safety devices, ensuring smooth operation.
• Universal Compatibility: Works with all central heating systems, including aluminium, for versatile use.

Key Features of Leak Sealer F4

• Rapid Action: Effective in as little as 1 hour, fully sealing within 24 hours.
• Non-Invasive Fix: Eliminates the need for invasive repairs, reducing maintenance costs.
• Boosts System Longevity: Prevents pressure loss, protecting boilers and extending system life.
• Eco-Friendly Formula: Non-hazardous, environmentally conscious solution.

How to Apply Fernox Leak Sealer F4

Add Leak Sealer F4 via a radiator, towel rail, or filling loop. Pair with Fernox Cleaner F3 to clear debris and Fernox Protector F1 for corrosion and limescale protection. Regular maintenance keeps your system at peak performance.

Why Choose Fernox Leak Sealer F4?

• Top-Rated Efficiency: Quickly seals leaks without affecting system performance, ideal for homeowners and professionals.
• Cost-Effective: Minimizes repair costs and downtime with no-drain application.
• Safe & Reliable: No risk of blockages, ensuring worry-free heating.
• Fernox Leak Sealer F4, central heating leak repair, boiler leak sealer, pinhole leak fix, heating system maintenance.