creda t622cw?

my creda continually knocks out the green dot thermostat ,i have cleaned and checked everything ,replace with new and a couple of months later blows again , i have the green dot thermo on left looking from back could this be wrong or is it overuse anh high temp settings including lack of draining the water holder , i have also checked the long armed micro switch although i could not see a white pop up that operates it , if i connect the two orange leads i get heat so i suspect all is working so green spot termo out again any ideas please