Our system filters and additives collection includes leak sealer, anti-freeze, corrosion inhibitor and more. Find products from top brands including Sentinel, Everbuild and MagnaClean to ensure you can do the job safely and efficiently. Our system filters capture contaminants before they reach the boiler, keeping them in better condition and making them last longer. Our additives improve the efficiency of both old and new central heating systems. Expect top-quality products and brands every time you shop with Trade Supplies Online.