cold air coming from vents
we just recently moved into a house "flipped" by a couple, starting in 2004. anyway, they said they replaced pretty much everything, including the furnace (gas heat). i noticed this evening that some of the vents are blowing out cool air, some upstairs AND downstairs. any advice? we know NOTHING about this type of thing. do we need to adjust the thermostat? should we have the furnace looked at? vents are open.