Just changing the stat again. When i seperated the stat (on the car) i was worried i was going to get my hands burnt by the hot water, but to my suprise the water inside the stat housing was cold?

Ive poured water down the end of the stat housing that goes to the rad, its filled up the rad and then obviously raised the water level in the header tank.

Just going to test this stat in hot water and then refit it, if it still doesnt want to play ball, i dont know what to do