I have 2012 SE model which has single manual heater and had no heat few year ago, but I got it "fixed" easily. you could try this: take out the kneel panel (just 1 or 2 nuts), and you will see the actuator mechanism on the center console side when you really crawl close to the floor. now pull out the electric connector to the actuator. then turn on the heater, now plug the connector back. You may need to do this several times. This "hot" action may jump start the stuck mechanism. In my case, it worked after I tried doing this. Then I apply some locker grease around the joints of the actuator. the heater works since then no problem.