Why Is My Home Air Conditioner Leaking Water Inside?
AC leaking water is a common issue encountered during the hot Florida summers. If you notice your AC leaking water inside your home, there are several potential causes for this problem.
First and foremost, switch your AC’s thermostat to “Off” to prevent any further damage to your home.
Understanding why this happens requires knowledge of how water forms on your AC in the first place.
If you suspect you need professional AC repair, don’t hesitate to call us at 407-710-8982 or schedule an appointment online, and we’ll send a licensed HVAC technician right over! View our service area in Florida.
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How Does Water Form in My Air Conditioner?
The inside unit of your AC contains the evaporator coil that cools the warm air blown over it. This process results in condensation (moisture) forming on the coil, similar to how water droplets form on a cold glass of water on a hot day.
The moisture on the coil then drips into a drain pan and flows down a condensate drain line (a white PVC pipe) that leads out of your home.
With this in mind, let’s explore some common causes of water leakage into your home.
Cause 1: Clogged Condensate Drain Line
The most frequent cause of water leaking from your AC into your home is a clogged condensate drain line. Dust, dirt, sludge, or mold can clog the drain line, causing water to back up into your home. In this situation, you’ll need to unclog it. Various unclogging methods exist, such as using a wet/dry vacuum on the condensate line. However, the most effective way is to have a professional use a special vacuum to remove the blockage.
Cause 2: Damaged or Rusted Drain Pan
If your air conditioner is 12-15 years old, the drain pan may be damaged or rusted through, causing water to fall right through. In this case, you’ll need to replace the pan.


Cause 3: Broken Condensate Pump
If your furnace and indoor AC unit are installed in the basement, a condensate pump is used to pump the water outside. If the pump breaks, the water isn’t pumped outside anymore, and you will need to repair or replace the pump.
Cause 4: Dirty Air Filter A dirty air filter obstructs airflow over the evaporator coil, causing the coil to get too cold and freeze over. When it melts, it drips an excess amount of water that the pan may not be able to handle. Check your air filter to see if it’s dirty and change it if necessary. It’s advisable to change your air filter every 1-3 months, depending on the season.
Cause 5: Low Refrigerant Similar to a dirty air filter, low refrigerant levels will reduce pressure in the AC system, causing the evaporator coil to freeze over. When the coil melts, water overflows the drain pan. Signs of low refrigerant include:
- The air conditioner isn’t cooling well
- You hear a hissing or bubbling noise (indicating a refrigerant leak)
Depending on the severity of the refrigerant leak, you’ll either need to repair the leak or replace the entire AC unit.
If you need a new one, read our article, “My Air Conditioner is Dying, and I Need a New One…Now What?”
