Heater Stuck on Hottest Setting Due to Broken Heater Blend Door on Mercury Mountaineer
Problem overview
A failed heater blend door or actuator can cause the temperature control for the HVAC system to stop working. A clicking sound from the dash area would commonly indicate an actuator fault. If the heater gets stuck on the hottest setting, the heater blend door may be broken requiring replacement of the heater box to repair the issue.
128 people reported this problem
55 commentsMercury Mountaineer vehicles with this problem
14 model years affected
Average mileage: 128,838 miles
(15,000 - 270,000)
Search for another problem
RepairPal ™Car Genius
Ask our experts about your Mercury.
RepairPal Car Genius™ is a free resource for vehicle owners seeking advice on maintenance, auto repair, shop inquiries, estimates, and finding a trustworthy repair shop in your area.
Call us at 877-913-1554
Available 9am – 6pm ET Monday through Friday
