Hello, so my 1995 325IS BMW started blowing significally hot air out of the bottom vents whenever the a/c or air gets turned on. My question is, generally, does the whole a/c unit have to be replaced when this happens, or could it be a minor fix? The heat is only present whenever the air system is turned on. The top a/c & air work fine but the bottom throws out some uncomfortable heat. If the whole unit has to be replaced, I'm assuming it's rather expensive.
What do you guys think?

(the water pump was recently changed a couple of months ago if that could have anything to do with it).

Thanks

bump

maybe the inlet to the vents came loose and now you getting engine heat into the car! not sure how you could fix that though. sowwy!

if its pumping out heat, chance is the heater valves are broke..
no heat out the windshield vent ?
face vents may be set to cold anyway ?

heater valve is located in the engine bay, against the firewall near the fuse box, easy change, just need to bleed the system well afterwards