Chevrolet Repair: Heater problem, chevy blazer, control doors

Question
I have a 1996 Chevy Blazer with 60k miles. I have noticed that the air conditioner works perfectly, but the heater doesn't heat at all. What could be wrong, and what can I do to fix it?

Answer
Hello Jimmy,
Make sure coolant is actually flowing through the heater core. often that quick connect on the intake manifold gets plugged where coolant will barely pass through.
Replace that with a regular hose nipple, and a clamped on hose.

The heater core could also be plugged.

A third possibility is the coolant is flowing fine through the heater core, but the air control doors are not working properly. See if all of the air doors move when directed.

Van