Where is the heater switch of Audi A6 in 2008?

On the home screen, select: car > air conditioner > icon (below), or

Please press and hold the button on the center console (below) for at least three seconds.

Open it immediately.

You can set the service time and immediately turn on/off the parking heater/ventilation through (the figure below). When this function is turned on, the color bar above the key will light up.