I have a 01 civic and the heater is not blowing warm air. I checked all the fuses, no luck. I had replaced the radio, so i figured I did something...So, I looked behind the radio, everything was fine. It blower works, its just not hot. The antifreeze level is great. To me it seems that there must be some sort of switch that allows coolent to go into the heater coil. Could that be the problem??Help!!! I can hear the sound change while turning the dial from cold to hot, the sound gets lower like the control is working, so Im thinking the control is good.

 

The heater core might need to be replaced, but I doubt that's the problem. Where isn't the heated air blowing, because my '01 won't blow heated air to my feet... weird, I know.

 

I get no hot air whatsoever. The temp guage goes up to normal also.

 

Then I'd say there's either a flow issue (of air) through the heater core, or the heater core isn't receiving radiator fluid.

 

check the flow valve. on the drivers' side firewall youll see a blue 'hose.' thats the heater cable. if you follow it, it will lead you to the flow valve. make sure it's connected and make sure it moves when you adjust the temperature setting.

 

I will try that, skipbarber. We shall see.