I have 2006 Blazer. Antifreeze needs to be at right level or no heat. Instead of changing my thermostat for very cold temperatures I use a grill snap on guard that adds plenty of heat to the cab and is adjustable. Gasoline will not burn well if the engine is too cold in severe winter driving. If you are losing at lot of antifreeze use the copper sealer and not the aluminum sealers.
They did'NT make the Trailblazer in 2000 might you be looking for information for a 2000 Blazer.
Heater Airbound? Heater control cable not working? Heater core plugged?
If you are standing in front of the truck with the hood up, it is in the back left corner to the right of the heater resistor.
Check the coolant system to make sure you are not low. An air bubble going through the heater core can make an odd sound.
No it will not, it will just back flush the heater core and clean it out.
this model does not have a heater control valve, it has a specail thermostat that controls flow.
You can but you still won't be able to get it out.
The most common problem causing a 2000 Blazer to stay on heat is a problem with the blend door. Check the blend door and its control circuit to fix the problem.
The heater blend door is not run by vacuum. It is run by an electric actuator.
Corrosion. Check connection at the module for corrosion.
I am having the same problem.. I have already had to replace the intake manifold gasket cause it was leaking, still no heat. We will be flushing out the heater core to see if that's the problem. I may have to replace the heater core, we will see.