An air conditioner can freeze up due to a variety of reasons, including:
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Inadequate airflow: When too many vents are closed or the air filter is dirty enough to block proper airflow throughout the system, an AC unit can freeze up because it can’t work correctly. The buildup of cold air can result in the refrigerant condensing on the coils.
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Low refrigerant level: If the system is too low or too high on refrigerant, it could cause the temperature of the evaporator to drop, freezing moisture and thus icing up the system. This could be due to a refrigerant leak that a contractor will need to repair.
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Dirty coil: If the evaporator coil is dirty, it can cause the refrigerant to condense and freeze, leading to a frozen air conditioner.
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Damaged or broken blower fan: The blower fan pulls in warm air from your home and pushes out cool air from your AC unit. If there’s something wrong with the fan or its motor, your AC won’t get enough airflow to prevent ice from forming. The lack of air movement will cause the evaporator coil to get extremely cold and freeze the condensation it has collected.
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Mechanical problems or refrigerant leaks: Air conditioners are full of moving parts that can get stuck, broken, or clogged. Refrigerant lines can kink, fans can stop moving, filters can become clogged, and things can leak. Any of these things causes a drop in pressure, allowing the refrigerant to expand too much and become too cold.
If you notice that your air conditioner has frozen up, you should turn off the AC unit and let it thaw completely before turning it back on. You should also check the air filter and replace it if it is dirty. If the problem persists, you should contact a professional HVAC technician to diagnose and repair the issue.
