My heater is not working?

Check /replace thermostat
check heater hoses under hood
they should be hot both if you have one hot and one cool flush heater core
1st check /replace thermostat
let me know

Could also be you heater hvac blend door.

This is my check list for no heat hope that help
1- Check coolant level and add if needed
2- Start and warm up the engine, does engine reach operating temp? If not check and suspect thermostat, if it does go to next step
3- Check heater hoses by the firewall both should be hot, if so problem is inside the HVAC box and check doors and actuators, if not check if have any restriction between engine and heater core by the firewall if not isolate and flush heater core

Hi:
What seems to be the problem with the heater?

Joe

Hi:
I'm glad to be here for you, and I hope I can help. To get started, do you mean the blower motor isn't working or it does work but all you get is cold air? Also, when you drive, does your engine temp gauge show that the engine is running at a normal operating temp?

Let me know.

Joe

Because your coolant was changed, you have to make sure that u bleed the system. Air pockets=no heat. Also have your engine coolant temperature sensor checked for faultiness, if bad, replace it.
Let me know the outcome.

One way is to look on top of the coolant inlet cover where the thermostat goes, there is might be a little bleed screw in which you have to slightly open when the car is on and has reached operating temp. With the heater on full blast. The other is to take the coolant cap off before your start your car. Then you do the same thing as the other way and turn your heater on full blast and as the car reaches operating temp. Youll see the coolant bubbling and releasing air as this is happening. Youll notice that the coolant is getting slightly lower and that is when you add a little coolant at a time until you get to the correct level. Usually when it stops bubbling thats when all of the air has been purged. I have to caution you, if you don't really know what your doing you should have someone help you and wear the proper protection equipment so that u don't get scolded or splashed in your eye.