Heater not working

Check and test the thermostat and heater control valve if both okay could be one of the following-air mix/blend/mode door problems, vacuum and actuators to include the HVAC control module

Heres a guide on replacing a blend door actuator. Not vehicle specific, but it will give you an idea of whats involved

https://www.2carpros.com/articles/replace-blend-door-motor

Attached below you will find the diagrams to replace the blend door actuator fro your vehicle

Heater Core "” Plugged

WARNING: The heater core inlet hose will become too hot to handle if the system is working correctly.

Check to see that the engine coolant is at the correct level.
Start the engine and turn on the heater.
When the engine coolant reaches operating temperature, feel the heater core inlet and outlet hose to see if they are hot.
If the inlet hose is not hot:

the thermostat is not working correctly.
If the outlet hose is not hot:

the heater core may have an air pocket.
The heater core may be restricted or plugged.
If both are hot, the temperature blend door in the heater plenum may be broken or stuck.

If the blower motor is cutting out, check the wiring to the motor to make sure it is tight, clean, and not damaged. If it is good, check to see if it gets continuous power while moving the wiring around. If it does, chances are the motor is going bad.

Check coolant level
Is the car reaching operating temp
Check heater core hoses if both are hot,
if yes then suspect and check the blend door actuator
if not the heater core need to be flushed again as a 1st step
these are the steps
Warning: never remove the pressure relief cap under any conditions while the engine is operating. Failure to follow these instructions could result in damage to the cooling system or engine and/or personal injury. To avoid having scalding hot coolant or steam blow out of the cooling system or degas bottle, use extreme care when removing the pressure relief cap from a hot cooling system or degas bottle. Wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly until pressure begins to release. Step back while the pressure is released from the cooling system. When certain all pressure has been released, press down on the pressure cap (still with a cloth), turn and remove pressure relief cap.
Engine cool
lower the coolant level
Locate the two hoses running to the heater core
disconnect them at the engine side leaving hoses connected to heater core throw the firewall
use garden water hose and compressed air if possible
run the water and follow by air throw one side and out the other and vice versa
do that two to three times watching what leaving the heater core you are looking for the good flow and clear water to run throw
reconnect hoses
top off coolant system
good luck
let me know

Check the heater core, heater control valve and the air blend door-

This is the Check list for no heat
if you go through it, it should show when is the problem
I would assume its a heater core that need to be isolated and flushed

Check coolant level
Is the car reaching operating temp (if not or engine taking long time to reach operating temp suspect and replace thermostat )
Check heater core hoses if both are hot,
If both hoses hot and not enough heat inside suspect blend door actuator
If one hose hot and the other warm or cold the heater core need to be flushed (very common)
as a 1st step
these are the steps
Warning: never remove the pressure relief cap under any conditions while the engine is operating. Failure to follow these instructions could result in damage to the cooling system or engine and/or personal injury. To avoid having scalding hot coolant or steam blow out of the cooling system or degas bottle, use extreme care when removing the pressure relief cap from a hot cooling system or degas bottle. Wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it slowly until pressure begins to release. Step back while the pressure is released from the cooling system. When certain all pressure has been released, press down on the pressure cap (still with a cloth), turn and remove pressure relief cap.
Engine cool
lower the coolant level
Locate the two hoses running to the heater core
disconnect them at the engine side leaving hoses connected to heater core throw the firewall
make sure you pinch and close the bypass hose between the two heater hoses
use garden water hose and compressed air if possible
run the water and follow by air throw one side and out the other and vice versa
do that two to three times watching what leaving the heater core you are looking for the good flow and clear water to run throw
reconnect hoses
top off coolant system
good luck
let me know

Hi
The smell and window icing tell me heater core leaking. If coolant is low that would cause your overheating. Assume it is cold where you live. Do you see white smoke a water comming from tail pipe? Doea oil look normal or a little like chocolate malt? Yes to either question head gasket failure.
Let me know
Merry Christmas

O.K. Heater core leaking will not cause car to overheat It will if coolant is run low.
If headgaskets are faulty and leaking that will cause car to overheat.
Over heating at low speeds can be caused if cooling fans are not operating. Verify they are operating.

Replace the thermostat and inspect and test the heater control valve and also the heater core.