Why Is My Air Conditioner Leaking Water? Common Causes and Solutions

Air conditioner leaks can be concerning, but they are often caused by common issues that can be addressed. Understanding these issues and knowing how to resolve them can help maintain your air conditioning unit’s efficiency and prevent damage. Here are the main reasons why your air conditioner may be leaking water and how to fix them.

Clogged Condensate Drain Line

One of the most frequent causes of AC leaks is a clogged condensate drain line [1][2][3]. Over time, the drain line can become blocked with dirt, dust, and algae [1][3]. To fix this, clean the drain line using a wet/dry vacuum or a long wire brush. Pouring a mixture of water and bleach down the line every six months can help maintain its cleanliness [3][4].

Dirty Air Filter

A dirty air filter can restrict airflow, causing the evaporator coils to freeze and then thaw, leading to excess water [1][3][4]. To prevent this, replace the air filter every 30 days or as recommended by the manufacturer [1][4].

Low Refrigerant Levels

Low refrigerant levels can cause the evaporator coils to freeze, resulting in water leakage when they thaw [1][2]. It is advisable to have a qualified HVAC technician check and refill refrigerant levels to resolve this issue [1].

Damaged or Rusted Drain Pan

In older AC units, typically those 12-15 years old, a cracked or rusted drain pan can cause water leakage as it can no longer properly contain condensation [1][2][4]. Replacing the damaged drain pan is the solution to this problem [1][2].

Frozen Evaporator Coils

Frozen evaporator coils can be caused by restricted airflow, low refrigerant levels, or dirty coils [1]. To fix this, ensure proper airflow, clean the coils, and maintain adequate refrigerant levels [1].

Incorrect Installation

Improper installation, such as incorrect leveling or sizing of components, can lead to leaks [4]. Have a professional check and correct the installation if necessary to prevent this issue [4].

Condensate Pump Issues

If your AC uses a condensate pump, it may be broken or unpowered, leading to water leakage [2]. Check the pump’s power supply and replace it if faulty to resolve this problem [2].

Extremely Cold Outdoor Temperatures

Running the AC when it’s too cold outside can cause the coils to freeze, leading to water leakage [2]. To prevent this, avoid using the AC when outdoor temperatures are below 60°F (15.5°C) [2].

Conclusion

If you notice your AC leaking water, it’s important to turn off the unit immediately to prevent further damage [3][4]. While some issues can be addressed with simple maintenance, others may require professional assistance. Regular maintenance, including changing filters and cleaning drain lines, can help prevent many of these problems [1][3][4].