Daniel&John's video: Central Heating System Losing Pressure Or Leaking - Fernox Leak Sealer F4 Express Via Radiator

Our boiler has been losing pressure while the heating system is on, we can't find the leak from any pipes or radiators however the central heating system pressure gauge is dropping over time when the heating is on which suggests a small leak. So we're going to try a product made by Fernox called Central Heating Leak Sealer F4 Express and can be applied via the filling loop or directly into the top of a radiator as we have done in this video. We hope our video is useful and solves your problem, fixing the leak will save water and make the heating system more efficient, not only that it should also extend the life of the boiler as well. You will need some basic tools (adjustable spanner/vise grips) , including a radiator valve bleed key, a container for the water and old towels in case of spillage. The leak sealer is available from most DIY stores, but here's a link to it: https://amzn.to/3N2nsuD