A heater control assembly has a transmission mechanism including a first bevel gear rotatable together with a rotary knob, a second bevel gear engaging with the first bevel gear, a first spur gear rotatable together with the second bevel gear, and a second spur gear engaging with the first spur gear. The lever has one end connected with the cable and the other end which is fixed on the second spur gear so that the lever may swing in accordance with rotation of the second spur gear to pull and push the cable.