I have a 2003 Blazer and my heat is temperamental. It blows hotter than blazes for a bit then turns warm. It's never overheated since I have owned it. No leaks, but I get airflow from the front vents no matter what position I have it on.

I plan on replacing the thermostat as a first step.

Any ideas what else it could be?

I'm in Minnesota and winter isn't too far off.

 

hvac switch or one of the 4 pods. or line to the pods. here any hissing noises? check for a search for hvac - lots of pics and posts

 

Thank you Joe! Another avenue to check out! And no, I don't really hear a hissing, I will have my son listen (I have hearing loss). Would it be in the cabin or engine?

 

have a full read of my thread, it's pretty detailed..just lacks pictures....

someone might correct me who knows more but have a read...

https://blazerforum.com/forum/2nd-ge...hissing-95272/

also yes ---- make sure you try a new thermostat - that did it for me once !!
that is all it needed when mine would have work!!!!

 

Thanks again Joe! Looking at it and replacing thermo this weekend!

 

also here is a good link


https://blazerforum.com/forum/2nd-ge...no-heat-14749/