There is a TSB for this and likely yours would be covered, ask your dealership.
The top section of this forum category has sticky' links-links that will stay there for your reference, refer to the Ford Ex TSBs post.
Even if your build date/year are not in the TSB the problem is the same, so ask about repair warranty coverage.
12-1-8 DUAL AUTOMATIC TEMPERATURE CONTROL (DATC) - BLEND DOOR ACTUATOR INOPERATIVE
ISSUE:
Some 2011 Explorer vehicles equipped with DATC system may experience unresponsive temperature change when requested and/or erratic temperature change.
ACTION:
Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE
Remove temperature blend door actuators, refer to Workshop Manual (WSM), Section 412-00.
Suspect parts have a black cover and new service part has a white cover.
Remove alignment feature from new actuators. (Figure 1)
Figure 1 - Article 12-1-8
Support actuator flange so there is not stress on the actuator body. (Figure 2)
Figure 2 - Article 12-1-8
Drill out the 2 webs with a 3.17 mm (1/8") drill bit. (Figure 3)
Figure 3 - Article 12-1-8
Install new actuators, refer to WSM, Section 412-00.
Reprogram the Heating Ventilation Air Conditioning (HVAC) module to the latest calibration using IDS release 76.04 and higher or 77.01 and higher. This new calibration is not included in the VCM 2012.1 DVD. Calibration files may also be obtained at
www.motorcraft.com.
PART NUMBER PART NAME
AA5Z-19E616-C Motor Assembly
WARRANTY STATUS:
Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT: Warranty/ESP coverage limits/policies/prior approvals are not altered by a TSB. Warranty/ESP coverage limits are determined by the identified causal part and verified using the OASIS part coverage tool.
OPERATION DESCRIPTION TIME
120108A 2011 Explorer: Replace The Blend Door Actuators Includes Time To Modify The New Actuators And Reprogram The HVAC Module (Do Not Use With Any Other Labor Operations) 1.1 Hrs.
DEALER CODING
BASIC PART NO. CONDITION CODE
19E616 42