02 Stratus--no heat at idle

Blower does not push hot air until car is put in gear. I've tried starting the car, placing it in neutral w/ the e-brake on and seems to get somewhat warm, but not what it should be. Doesn't matter how long it warms up, even at normal operating temp does not push hot until I shift it in gear. Any ideas?

sounds like possibly one of the vacuum lines behind the HVAC control unit has a leak in it somewhere.