That's interesting, no tap and it goes to the thermostat as you suggested. I'll look into SLow ("series landrover owners" as a guess?). There is a few things on the old girl that go nowhere, electric wires and cables and it would be great if there is a meet where I could get some opinions.
RE cleaning the core, I'll have to live with a temporary clean/fix and get it done at a later date, and that genuine hose (100mm) is expensive for what it is!
Here is a pic
Attachment 117775

