LavaTap - Fernox F4 Express Leak Sealer 400ml - Central Heating Leak Sealer Spray for Radiator and Pipe Leak Repair, Stop Leak Solution for Sealed Systems

Fernox F4 Express Leak Sealer is a fast-acting internal leak sealant for minor leaks in central heating systems. Specially designed for sealed and combi systems, this 400ml solution works without the need to drain the system, saving time, water, and labour. It quickly locates and seals hidden micro-leaks in radiators, pipes, joints, and heat exchangers by forming a durable polymer seal wherever air ingress is detected.This leak sealer is suitable for use with all standard central heating system materials and is safe for boilers, pumps, and valves. The air-powered solution can be applied directly into the system via a radiator, filling loop, or TF1 filter using the included universal adapter. With a treatment capacity of up to 130L of water (or 16 radiators), it is an efficient choice for household and light commercial systems.Unlike traditional radiator sealants, Fernox F4 Express is environmentally responsible-it uses compressed air instead of chemical propellants and comes in a recyc