The Fernox Express F4 400ml Central Heating Leak Sealer is a high-quality product designed to seal leaks in combi boilers with a tank capacity of 75-150 litres. Made in the United Kingdom, this sealer is suitable for gas and petrol-powered boilers, and has an energy efficiency rating of A+++. The product is easy to use and comes in a sleek white colour, making it a convenient and efficient solution for fixing leaks in your heating system. With a water temperature range of 40°C to 60°C, this sealer is a reliable choice for maintaining the performance of your boiler.
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