Heater not working

My heater will not work i move the lever to hot and all i get is the A/C. Also it doesnt seem like the A/C turns off. The switch to change from face to feet doesnt seem to work either. I have looked in the Haynes repair manual and all i can find is that i need to take it to the shop. The book says if a problem is detected an error code is displayed by flashing lights on the dashboard pushbuttons. How do i get the lights to flash and what do the codes mean if and when i do?
Any help would be greatful.

As for the temperature/blower issues, have you tried taking the face off and checking the wire connections in the rear? It could be that something has come loose and it just got stuck in whatever the last process was. You mentioned having the manual, so this would help walk you through removing/checking/replacing the face.

For the codes, you can't make the lights flash (it would be great if we could). When/if the vehicle detects a problem, which is usually one that would cause it to break down and not run, it will flash the check engine light. I wish it also did this for the convenience features too (AC, heat, etc.). You can go to an auto repair shop or parts store to get the codes pulled, then they have a book that interprets the codes for you and says specifically what is wrong. Hope this helps.