Next to No Heat in the Cabin...Causes?

So last week I noticed that my cabin is not getting as warm as it used to, and if you feel the air coming out was luke warm at best and felt "cool" and this is after an hour drive. So I googled the thermostat (just read there is 2?) and came across a thread about removing the air from the system so I did that and although better, still not great. Now that its -30 degrees out, I can really tell its not working well. My coolant was nearly topped off so I do not believe it to be leaking anywhere, no spots under car either, just looking for some things I can check to see if they need replacing as the nearest dealer is 90mi away and I don't really have time to get there soon.

Hopefully the good news here is I have the receipt from the previous owner that the coolant pipe HAS BEEN replaced last May, so hopefully this will be something else.

Go into the climate portion of Idrive (push center console knob to left.) Between the arrowed vents for choosing where you want the air to come from, click on the temperature slider and slide the left and right all the way to the left (red). Next, make sure that the arrows are at least selected for the front vents. If you want heat on your feet, select those arrows...

already did.

Dont know if this will help, but back in the summer I had more heat than a/c coming out of my vents and this is what I had to get replaced:
http://www.partsgeek.com/catalog/200...ter_valve.html

From my understanding, it can work for the opposite issue that you may be having. Hope this helps.

I noticed that same issue a while back. After checking the vent controls, fluid levels, I decided to change my thermostat bc of a thermostatic fault error and it solved my heating problem.

There is a AUX pump for the heat.