Buick lesabre heater problems

[chuckie669]

Hey guys,
Have an 02 lesabre and the heater does not work.

I've checked the hoses to the heater core and they both get hot. Noticed the thermostat was bad so replaced that.

On any vent setting the ac blows through ice cold regardless of were the slider is.

When I have it on specifically heat, neutral air blows out the floor. This is the only setting where I can have anything other than cold air.

Is the blend door or actuator my next step in testing or should I look for something else?

[chuckie669]

Has anybody worked on heaters or am I just in a bad section?