Hi Guys - I have a unit without air-con, it has two controls on the dash - one for each side of the cabin - blue at one end for cold, grading to solid red the other, with the TEMP markings 18, 20, 22, 24, 26 on each. Usually when these are set on a temp marking, you can hear a valve kicking in/out. Now there is no sound, even if set on MIN the heat is on MAX.
Could this be the sensor in the sunroof complex, or is the valve that's died??