I got an 05 EX. On frosty mornings, I will start my car 15 minutes before I leave for work. When I go out to leave, the winshield is just as frosty as when I started it. I get in my car and there's cold air blowing out of the vents. Yes, I have the defroster on. I put a new thermostat in last week, flushed the coolant and put plenty in. The hoses are nice n warm just a few minutes after I start it, so there's no clog. So what could it be? Engine coolant temp sensor? I'm running out of eliminations.

 

Engine warm but no heat from the heater means either:

- the system is not full (the radiator must stay absolutely full to the top)
- the heater core is clogged
- or the linkage from the hot/cold control on the dash is not moving the air door and opening the water valve like it should.

 

Turn the temperature **** all the way to the red. Haha.