Sometimes ice buildup on an air conditioner is not the result of outdoor weather conditions. Ice in or on your air conditioner can be caused by many things, including problems with the fan, debris, or a low coolant level.
- Fan problems: The evaporator unit’s fan is responsible for keeping coils above the freezing point so that the condensation on the coils cannot freeze. A faulty fan that spins too slowly, or not at all, can cause coils to drop in temperature and the buildup of condensation freezes.
- Debris: Any sort of debris in the coils of an indoor or outdoor unit can restrict airflow, resulting in the same problem that occurs with a faulty fan. If a coil is dirty, the system should be switched off until it can be cleaned or replaced. Keep the coils clean inside and out. One big problem is when grass clippings and other debris like cottonwood covering the outdoor unit. Keeping the unit clean will help airflow.
- Low coolant level: If the coils are clean and the air is moving properly, the refrigerant level is most likely the problem. When the level of refrigerant is low, the coils will be at a temperature much lower than normal. The excess condensation builds up and forms into ice. Low coolant also can mean there is a leak. Refrigerant leaks do not repair themselves — they must be sealed by a technician and new refrigerant added. Depending on the location and severity of the leak, as well as the age of the equipment, you may need to consider replacing your unit.
- Other causes: Dirty filters, a clog in the system, broken valves, problems with vents or registers, thermostat issues, or a blocked drainage system also could also result in ice on your air conditioner.
Regular service and inspection of the system are necessary for the prevention of ice buildup on your air conditioner. Water dripping outside from the unit is normal, especially when it’s humid. However, water dripping from inside the system and collecting in the drip pan is not a good sign. If you hear ice chunks or notice ice on the air conditioner, turn the system off and call a technician right away. Continued use of a frozen system can damage other parts.