A6 won't warm up...

[bluezie]

I have a 2014 3.0 Q, and there is no coolant shut off valve. The coolant runs through the heater matrixes at all times, and the heat output is adjusted by motorized flaps blending hot and cold air.
Sounds like you have a sticking flap in the climatronic. Using VCDS, you can check all the flaps and sensors.

I stand to correct myself, there is a coolant shut off valve on the C7, I was thinking about my C5 which doesn't, so coolant flows through the heater at all times.
That said, the above fault with a stuck flap can still cause slow, or no warm up of cabin temperature.

[LEAR]

Hi,

Error code is B109007 - Defroster flap motor mechanical malfunction passive/sporadic