Air conditioning system misbehaves

[DOVEL]

Model 3 Long-range AWD.

Upon entering the car after a day it was not driven, the air conditioning system begins heating vigorously, even though the temp control is set to 20 deg-C and the weather outside is quite warm. It doesn't then respond to temp control at all. It returns to normal only after driving for a while, or after sliding the temp control all the way down to the "Low" position. (I can't distinguish between the two causes because both occurred at the same time.)

Please advice, thank you.

 

[mirkop82]

Which model year is your car? I understood that recent ones equipped with the heat pump are slower to blow cold air than older models.
The hot air might just be the cabin air being recirculated

 

[larstobi]

My 2019 Model 3 Long-range AWD (Norway) behaves in a similar way. It doesn't have a heat pump.

 

[Randy-12]

Have you tried resting the car by holding the 2 steering wheel buttons?

 

[Big Earl]

Likely a bad cabin or vent temperature sensor that makes the car think it’s colder inside than it really is. Service should be able to run diagnostics and identify the problem. You might also be able to self-diagnose from the HVAC section of Service Mode, although Tesla will still want to do their own diagnosis before replacing parts.