Dumper - Thanks.
Chuggy - I'm unsure on thermostat, but the heater/fan was definitely throwing some hot air.
The disconnected plug (two pictures north of here), couldn't be anything to do with it, could it?
I'm completely unsure what lights should come on when the key is turned to the primed position (for symbol light check/diagnostic), but I thought at least the Glow Plug warming light should come on. All I get is a battery light, and one other which I can't quite remember right now.