a question if you don't mind JC. When you change from an old style gravity fed system to a new combi boiler how great is the risk of older pipes springing leaks?
Sorry yes. it should be Weissman. Got fuddled as I'm reading a book on the demise of Weimar republic.
Can endorse Vaillant, we've had ours in since 2004, just had a single repair to, I think, a diverter valve and that's it.