my heater won't work, I only get cold air on 2005 Mercury Mountaineer

my heater doesn't work , I only get cold air all the time.
when i switch to hot air all I get is this clik, clik, clik
behind the air controls

Asked by for the 2005 Mercury Mountaineer
The clicking noise you are hearing is the blend door actuator trying to open the door. Most likely the motor will need replacement.