Setting

• Some air conditioner units feature a fan button that allows the user to select a fan speed. The air conditioner might be set to “Low,” which means the fan turns slowly and produces minimal air circulation, which could be a problem when a room is stiflingly hot. A press to the “Fan Speed” button increases the fan speed to the next level, and yet another press to the button advances it even further. Your air conditioner might feature fan speeds of “Low,” “Medium” and “High.” A “High” fan speed is the maximum and commands the internal fan to turn quickly, producing maximum air circulation.
  
  

Debris

• Oftentimes debris, such as a plastic bag or string, can get sucked up into the intake grille or inserted by a child. The debris wraps around the fan and hinders its movement, which causes the fan to turn slowly. Also, if the fan is improperly installed in the air conditioner, the fan blades might strike the sides of the fan housing, which slows the rotation of the fan. Front or side panels to the unit can be removed to reveal the fan compartment. Any debris should be removed. If you inspect the inside of the fan housing, areas where the fan strikes the housing could be apparent. If the fan strikes the housing, the fan should be removed and reinstalled properly.
  
  

Bearings

• If the bearings of the evaporator fan are grimy or dirty, the fan doesn’t turn as freely as it could. When the panels of the air conditioner are removed to reveal the evaporator fan compartment, give the fan a turn by hand. The ball bearings need to be oiled with electric motor oil If the fan doesn’t turn freely. If the fan turns easily, the bearings are fine and the fan capacitor might be damaged. A technician should be called for repairs.
  
  

Ice

• While a slow-turning fan can cause ice buildup inside the unit, ice can also build up due to outside weather conditions or a disconnected thermostat. When ice builds up within the unit, it blocks air from blowing from the vents, which mirrors the effect of a slow-turning fan. If outside weather is lower than the thermostat setting and the unit is set to cool, the unit might freeze. Also, if the thermostat is broken or disconnected from the compressor, the compressor might continue to run after the fan shuts off, which causes the unit to freeze.