im not exactly sure what is wrong with my heater but there is something wrong, my ac works fine in hot and cold, but my heater never works, even when the **** is pushed all the way to the heat side it still blows out cold air, does any one know what may be wrong?

 

have you tried bleeding the system?
try a flush too

 

could be the heater coil. Most cars when the heater coil goes bad it'll blow cool air.

 

sounds like a stuck heater control valve. its by your firewall, there is one 4/5" pipe goes in from engine block and another 4/5" goes out into your heater core. this valve gets regulated by vaccum and pressures that your engine creates. you might have to check and replace the entire unit if needed. also try flushing your coolant sys too