Cold air blowing from heater vents

If its not a defective thermostat-could be one of the following -air mix/blend/mode doors and a vacuum/actuators-HVAC control module

This guide can help

https://www.2carpros.com/articles/car-heater-not-working

Honestly Sir-it really depends what needs to be repaired and also the labor cost varies with location-the best thing is to shop around-could be just as simple vacuum hose disconnected or a binding door its hard to say-they have to go behind the dash to get at it.

To give your feedback contact the webmaster@2carpros. Com or click on the button of the main page contact us-Thank You and have a nice day

Here are a few suggestions:

-make sure your level of coolant is good, and the system bled for air.
-The blend door actuator may be out.
-The blend door may be broken.

When you turn the switch from cold to heat, do you hear the blend door moving inside the panel?

Here, check this website, it'll give you an idea of what could be your problem:

heatertreater. Net/Mercury%20Sable%2096-07. Htm

Great suggestions
Also we find it
Very common for the heater core to be clogged and need to be flushed
Isolate and flush heater core
Need to know how let me know

It is quite likely that the heater core is clogged. It generally gets full of debris that doesn't settle in the radiator.

Drain the system, and have a qualified repair technician remove the heater core. It is located inside the car under the dash, and can be cumbersome to remove. Make sure they put plenty of towels down to absorb radiator fluid as this stuff reeks and is difficult to remove from carpet.

Flushing out the heater core manually, assures free flow of water, reinstall then check for leaks. Refill with the proper 60/40 mix of antifreeze to "distilled" water, and leave the radiator cap or expansion tank cover off, while you run the engine to purge the system of air. Once the engine reaches an optimal temperature of 180 degrees, close the cover, and check for heat.

If the car doesn't have heat at this time, then either you were sold a defective thermostat or the heater door isn't opening up properly. In which case the vaccuum lines may be broken.

Hi:
It sounds like the heater core may be plugged. Feel both heater core hoses to see if they are both hot with the engine running and the heater on.

Let me know what you find.

Joe

If the knob going round and round
have to start by checking the knob and switch 1st
check heater hoses if both hot
problem is on the inside

good luck

Sounds like the heater blend door actuator dorman part number 604-206. Otherwise something is blocking the door itself. Let me know what you find.

Check the thermostat and the heater core if its clogged-start here