In colder months, you may find that the air conditioner blows cold air inside and has a build up of ice on the outdoor unit. Depending on the age of the unit, it will most likely have a de-ice function that allows it to monitor the ice build up on the outdoor unit and will occasionally go into the de-ice mode to clear the ice. The full de-icing mode can last up to 30 minutes. Please do not attempt to turn off the system during this mode to ensure the air conditioner completes its procedures in full.