MY AIR CONDITIONER DID THE SAME THING BEFORE. WHEN THIS HAPPENS, TURN IT OFF UNTIL ALL THE ICE THAWS OUT. OR YOUR AIR CONDITIONER WILL BE RUINED. THE REASON IT FROZE IS BECAUSE THE TEMPERTURE OUTSIDE WAS NOT HOT ENOUGH AND YOU NEED TO TUN IT ON LOW WHEN IT IS 70 OR BELOW OUT.
There might be a number of reasons as to why your air conditioner is freezing up and some of them include; your air conditioner may be running low on refrigerant fluid, your air conditioner does not have enough air circulation to maintain the cold coil warm enough to prevent it from freezing, the fan in your air conditioner is not working properly or your air conditioner has a faulty thermostat. For more information, contact a qualified air conditioner technician or log on to http://energyboomer.typepad.com/energyboomer/2007/08/why-does-my-air.html.