I have a 2008, LS HHR. When I turned the cabin temp to warm and turn on the blower, the air the blows out stays cool. I know the temp control is working fine because when I turn the temp back down to cool and switch on the A/C it blows icy cold air. My passenger floor board is not wet, so no water leak. The car is not over heating or getting hotter than normal at all, so I know the thermostat is functioning. The head unit underneath the front center councel/dash is warm to the touch, so I know there is warmth being produced, but its just not being blown out for some reason. Has anyone else had this problem or have any suggestions on how to fix this? It's getting colder and it really sucks to drive to work every morning shivering. Thanks all!!

 

Sounds like the heater core is plugged. I have no experience with this on an hhr but I have fixed this issue on other vehicles. There is two smaller hoses going into the firewall and they are close together. Just looked under the hood of my ss and saw them closer to the drivers side. You will have to disconnect both hoses from the engine...you may lose a little coolant. With both hoses disconnected take a garden hose and hold it against one of the hoses and have someone else turn on the water. This will shove water through the heater core and remove the coolant buildup.

 

welcome to the site Bjarvis hope you can get the heat flowing again.

 

Could be the heat flapper door isn't opening....... You said heat can be felt on the unit under the dash, so the heater core wouldn't be plugged.

Also have you checked the coolant level, just to be sure?

 

to the forum BJarvis!

It does sound like the blend door in the dash is stuck in the cool air position, but as has been said here before, check your coolant level too.

 

I would start at the blend door but I still would not rule out the possibility of the temp control switch. The AC button and the temp rotor may work/not work independantly of one another. In other words when you turned back the rotor to cold nothing changed because nothing had changed when you switched it to hot but when you activate the ac button the ac will add extra cooling like it is supposed to do. Hope that makes sense. Myself, I would still start looking inot the blend door in the box.

 

From my past experience with this system I think the blend acuator is located behind the glove box. You can pull the inside box back (after releasing the tabs) and see it. Then move the selector switches and you can see if it move or not. Hope this helps.

BTW Welcome to the site!

 

Just a really dumb suggestion, the selector is not set to defrost right. I have left the defrost on and could not figure out why it was so cold in the car. The A/C is on in defrost with no indicator light to remind you. Like I said, nobody could be as dumb as me.

 

Can't you turn on the a/c then turn up the temperature control, all the way, to see if it warms up the air.

I haven't tried this in the HHR. But in previous GM vehicles, when I did this, I noticed a considerable difference in air temperature blowing out (works really well for clearing "fog" off the windows). If there is no difference in temperature wouldn't that indicate a bad temperature control switch??????

Oh and WELCOME, BJarvis. Sorry your first post is about having a car problem.

 

I have not had this problem on chevys but on the dodges I have had the hvac system lock up and not control tempature to fix the dodges we would have to disconect the battery for a few min. then the system will reboot and start working again. Couldn't hurt to try this on yours.