I have a 2007 Hyundai Elantra Limited, with 140,000 miles and I'm not getting ANY Hot air coming from my vents when i turn my heat on. I get air coming out but it's not hot and even when going above 2000 rpm's it never get's hot period. There is absolutely no diff in air temp from the heat running to just the fan running. The air never gets hot period . My coolant system is working properly and I don't smell any coolant to signal a bad heater core. My car has plenty of radiator fluid in it and My thermostat, as far as i know, is working fine, since i changed it not to long ago. I ran some water into the intake hose and out the outtake hose to see if maybe there was a clog but the water ran out signifying no clog?? I hope it's not a bad Heater Core.You wouldn't believe what you have to go through to change the Heater Core in this car....It would probably be easier changing the engine out in my car, lol, then the heater core. Now, when i turn the *** on on the the controls from air to heat, I feel no diff in air, wondering if maybe HVAC controls aren't working right. You know, normally when you switch your AC unit from air to heat you can tell the air is changed from cold to hot and something has switched inside the car where heat is coming from. I'm leaning toward a malfunction in the Heater Control Valve.. It's winter and I need to get it fixed. If it is a prob with the HVAC controls, how complicated is it to fix it compared to changing out the heater core?? I have some days off of work for Christmas next week so It would be a good time to devote to doing a repair that extensive. I miss the good old days when all you had to do to change the heater core out was reach under the dash board, open where it was at and pull it out..

 

Did you at anytime have heat before or is this the first time you tried to turn the heat on?
What temperature did you set it on?

If everything else is as it is suppose to be then it could be the heater core or the blend door controls.
Sorry, don't know how to explain to you how to check it.

 

Since I don't sense any air change in my vents when I switch from AC to heat and everything else seems narrowed out, including Heater core functionality, I'm leaning toward the blend door controls not working. I'm wondering how difficult it would be to replace what needs to be replaced?

 

I need to locate and replace my Heater Control Valve. Trying to find schematics on where it's at from my autozone online repair manual but can't. Where would it be and how do i get to it//

 

On modern cars, the heater control valve is usually a vacuum operated or controlled
If the vacuum fails then the default position would be in the open position where hot coolant would be flowing all the time (unless clogged).

Don't know about the 2007 Elantra