I have a 2007 TSX, blowing cold air, replaced thermostat with new premixed Prestone, still blowing cold air, core is not leaking and not coding, parking it on these cold rainy days, it's a losing battle, help please, I'm at my wits end.

 

Check whether heater hoses are getting hot. If not, heat control valve is stuck closed, air trapped in the heater core hasn't been circulated out, or a heater core blockage exists.

good luck

 

Possibly blend door is not working.