Hi, I have discovered that boiler pressure is towards zero. Top up helps. Later discovery is that there is a weep in an upstairs rad return pipe rotting a cupboard ceiling. I am assuming the two are connected. Temp solution is a bucket. When pressure was at zero again I repressured which blew a pressure join on downstairs UFH manifold. Have now isolated this to fix. Presume no point in draining and recommissioning UFH with the leak elsewhere. Leak upstairs requires cutting ceiling out, which I am reluctant to do. However equally reluctant to have dysfunctional system with no ground UFH. Any thoughts?