Phanthom heat issues

I have a 2002 ford Taurus with a weird heating problem. The current situation is this; I have heat but it takes forever to function properly. The car has to run for a good hour or more before it starts to blow hot air. I have checked the thermostat, replaced the water pump, reverse flushed the heated core, all check out fine. Coolant levels are full and I have burped the system. I then moved onto the heater control valve & temperature control switch along with the blend air door actuator. As far as I can tell all these devices and components are functioning properly. However my problem Still persist, 5, 10, 20 minutes after starting my car in the morning it’s still blowing lukewarm air, then after an hour or so, Walla, hot air!

If anyone has experienced this problem before and has a solution PLEASE let me know, muchley appreciated. Thank you

The blend door has a motor actuator. You also have a fresh air inlet door that is vacuum operated. If it is open, you will get cold outside air all the time and the heater will not be able to warm it up enough.

In what manner was the cooling system burped?

Tester

Kefenimore I don’t have a recirculation / fresh intake control on my heater console, not sure how to test the functionality of the fresh air inlet door. I kind of pondered it but when the hot air finally comes on it is almost instant, But still would it take so long to blow hot?
It doesn’t seem to matter if I’m driving or ideling for an hour trying to trouble shoot.

As for the burping, I jacked it up, I run the car with the rad resivor cap off for 5 mins. Watching to make sure the level didn’t drop to much. Only had to put in about 1/2 liter of 50/50.

Try this.

Get the engine up to operating temperature. With the engine idling, loosen the upper radiator hose clamp. Take a small flat bladded screwdriver and insert it in between the upper radiator hose and the radiator hose neck. Allow the engine to idle until hot air comes out the vent system.

When you get hot air, remove the screwdriver and retighten the hose clamp.

Tester