2003 bmw 325i, the air is working, but two of the vents are blowing hot air. the other two are fine. what could it be?

what are blend doors? sorry i have no knowledge when it comes to cars.

Tom is correct check you stratification wheel and make sure it is on the blue dots. If thats ok and your a/c system is full of freon then you should check you water valve. This vehicle does not use a mixer flap in the air box to control the temperature it uses a water valve on the driver side near the air box, If that valve is stuck open then you will have heat coming in the passenger compartment even when the a/c is on. Hope this helps.

I have the same problem. The center vents are putting hot air after a while? Is there a temp sensor/thermal stat some where that may not working properly? HELP!!!!