Excellent info there RJ, cheers, I've checked the coolant spurt trick

Alternator belt was replaced after snapping driving down M74 in rain you could waterski in, so did it then. Water pump is working fine by looks of it
Will check the other bits of wiring before I bite the bullet and buy a new thermostat(and seal/ housing etc) This not having heat in the car when temp is never above 3oC is murder...
Slightly unrelated but I know you've got the knowledge,

I've got to change my wheel bearings on the front, would it be worthwhile/necessary to change the hubs at the same time? I'm leaning toward if I have the wheels off anyway I might as well but is there anything I should look out for?
Cheers NB