Faulty Heater Control

[Donmeado]

Hi all. I've noticed on my 2010 5.1 Cali (manual cab heater, not climate) that when the selector is on screen or feet, the temperature control is cold all the way to the las 1 click. I i switch to vents, it works normally. I mentioned it twice now on dealer visits and came back no fault found.

Any ideas? Sensor failure? Cheers, Richard

 

[Donmeado]

Last 1 click that should have been. The last click then goes hot.