Water leaking from an air conditioner's evaporator coil is a common issue and is usually caused by a frozen evaporator coil. Here's how it happens:
Condensation: The evaporator coil in an air conditioner is responsible for cooling the indoor air. As warm air passes over the cold surface of the evaporator coil, moisture in the air condenses on the coil, much like dew forms on a cold surface. This condensation collects on the coil and drips down into a drain pan below it.
Drainage: The collected water in the drain pan is then directed towards a drain line or tube, which is designed to carry the water away from the air conditioner and outside the building. This drainage system ensures that the water is properly disposed of and doesn't accumulate inside the unit.
Frozen Evaporator Coil: However, if there is an issue with the airflow or refrigerant levels in the air conditioner, the evaporator coil may get too cold, causing the condensate on the coil to freeze. When the ice on the coil melts during the defrost cycle or when the air conditioner is turned off, it can overwhelm the drain pan and drainage system, leading to water leakage.
Common reasons for a frozen evaporator coil include:
Clogged air filter: A dirty or clogged air filter restricts airflow over the evaporator coil, causing it to get too cold.
Low refrigerant levels: Insufficient refrigerant in the system can cause the evaporator coil to drop to extremely low temperatures, leading to freezing.
Blocked or clogged drain line: If the drain line is blocked or clogged with debris, the water cannot flow properly, leading to overflow and leakage.
Malfunctioning blower fan: A faulty blower fan can disrupt the airflow over the evaporator coil, contributing to freezing.
Thermostat issues: Incorrect thermostat settings or sensor problems can cause the air conditioner to run longer than necessary, leading to excess cooling and potential freezing.
If you notice water leakage from your air conditioner, it's essential to address the issue promptly. Turn off the air conditioner to allow the ice to melt and check for any visible blockages in the drain line or air filters. If the problem persists, it's best to call a qualified HVAC technician to inspect and repair the system to prevent further damage and ensure efficient operation.