I am only able to get two temperature settings from the temp thumbwheel when in heating mode: full heat or no heat. At a setting of 16c, I hear a relay clicking followed by no heat. At 16.5c, I hear the relay clicking again followed by full heat (max). I have cleaned my temperature sensor inside the car. I believe the one outside is in working order since the computer temp reading is accurate. There does not seem to be any vacuum leaks since I am able to get heat to the footwells, etc.