Experience the reliability and efficiency of the Fernox F4 Express Leak Sealer, a 400ml aerosol designed for use with central heating systems. This product is ideal for those seeking to maintain their boiler's performance while ensuring eco-friendliness. With its A+++ to E rating, the Fernox F4 Express is a responsible choice for homeowners conscious of energy consumption. Crafted with a durable metal tank lining, this sealer is suitable for gas or petrol-powered boilers and storage tank water heaters. The ease of use and effectiveness of this leak sealer make it an essential addition to your heating system maintenance routine. The model number 68455068 assures you of the product's authenticity and quality.