Sentinel Leak Sealer Features and Benefits Compatible with other Sentinel products. Manufactured under a quality system conforming to ISO9001. Will not cause blockages within the system.
Had 3 small leaks in my central heating combi system the worst of which was a small corrosion pinhole in a vertical radiator and 2 minor leaks from radiator valves. applied the sealant via my mag filter housing. The leaks were all fixed after the first time the boiler was put on line.
Can't speak for long term fixes but after 2 weeks everything is holding up.
Would recommend