Hi all,
I changed the thermostat on Monday but by Wednesday the water in the rad was very low so it looks like I'm no further. When I look at the realoem diagrams, there's feck all pipes in the circuit so I'll just have to disconnect each one and re-connect then in case one has a bad connection. The one thing I do know is that there's no leak at the connector into the engine block on the underside of the inlet manifold.
I'm wary of touching the pipe into the heater matrix since one pipe collar broke years ago but there was just enough of a stump to clamp the pipe with a jubilee clip.
C