Why does my aircon drip water
Why Does My Air Conditioner Drip Water? If you've noticed your air conditioner dripping water--whether from the indoor unit, outdoor condenser, or from ducts--it’s a sign something isn’t working quite right. While some moisture is normal in an air conditioning system, visible dripping or pooling water can signal a minor issue or a bigger problem that needs attention.
This article explains why air conditioners drip water, the most common causes, how to fix them, and how to prevent leaks in the future.
Is Water Dripping from an Air Conditioner Normal?To a degree, yes. Your air conditioner works by pulling warm, humid air from inside your home, cooling it, and blowing the cooled air back in. As part of this process, moisture from the air condenses on the evaporator coil (the cold part of the system located inside the air handler or indoor unit). This condensation drips into a drain pan and exits the system through a drain line.
So some water is a normal byproduct of cooling. But if the water is dripping visibly, pooling, or leaking onto walls or floors, it's likely a sign of a malfunction or maintenance issue.
Common Reasons Your Air Conditioner Is Dripping Water1. Clogged Condensate Drain LineMost common cause. Over time, the drain line that carries water from the drain pan to the outside can become clogged with dirt, algae, mold, or debris. When it clogs, water backs up and overflows from the pan, causing it to leak indoors.
Signs:
2. Dirty or Frozen Evaporator CoilA dirty evaporator coil can cause ice to form on the coil. When the system turns off or warms up, the ice melts quickly, producing excess water that the drain pan can’t handle.
Causes of freezing:
3. Damaged or Rusted Drain PanThe drain pan beneath the evaporator coil collects water as it drips off the coil. If the pan is rusted, cracked, or corroded, water may leak before reaching the drain line.
Signs:
4. Disconnected or Improperly Installed Drain LineIf the drain line becomes disconnected or wasn't installed securely, it can cause immediate leaking whenever the system runs.
Signs:
5. Low Refrigerant LevelsWhen refrigerant is low (due to a leak or improper charge), the evaporator coil can get too cold and freeze over. As with dirty coils, the thawed ice can overwhelm the drainage system.
Signs:
6. Blocked or Dirty Air FilterA dirty filter restricts airflow, which causes the coil to get too cold and freeze. This can lead to excess condensation when the ice melts.
Signs:
7. High Humidity LevelsIn climates with very high humidity, the volume of moisture in the air can overwhelm even a well-functioning AC system’s ability to drain water fast enough.
Signs:
8. Improper Installation or SizingIf your air conditioner is too large for your space or was installed incorrectly, it might short cycle or fail to remove enough humidity, leading to condensation problems.
Signs:
What to Do If Your Air Conditioner Is Leaking Water
How to Prevent AC Water Leaks in the Future
When Is a Leak an Emergency?If your air conditioner is leaking water near electrical components, soaking ceilings or walls, or causing visible mold growth, turn off the unit and call a professional immediately. Water damage can quickly become a much bigger (and more expensive) problem
While a little condensation is normal, your air conditioner should never visibly leak water inside your home. Most water-dripping issues stem from clogged drain lines, dirty coils, or neglected maintenance--but they can be fixed relatively easily if caught early.
Regular care and attention to your system can prevent leaks, protect your property, and keep your home comfortable all year round. If you’re unsure about the source of the leak or don’t feel comfortable handling it yourself, don’t hesitate to contact an HVAC professional.
This article explains why air conditioners drip water, the most common causes, how to fix them, and how to prevent leaks in the future.
Is Water Dripping from an Air Conditioner Normal?To a degree, yes. Your air conditioner works by pulling warm, humid air from inside your home, cooling it, and blowing the cooled air back in. As part of this process, moisture from the air condenses on the evaporator coil (the cold part of the system located inside the air handler or indoor unit). This condensation drips into a drain pan and exits the system through a drain line.
So some water is a normal byproduct of cooling. But if the water is dripping visibly, pooling, or leaking onto walls or floors, it's likely a sign of a malfunction or maintenance issue.
Common Reasons Your Air Conditioner Is Dripping Water1. Clogged Condensate Drain LineMost common cause. Over time, the drain line that carries water from the drain pan to the outside can become clogged with dirt, algae, mold, or debris. When it clogs, water backs up and overflows from the pan, causing it to leak indoors.
Signs:
- Water dripping from the indoor unit or ceiling
- AC shuts off due to a full drain pan
- Musty or moldy smell
- Use a wet/dry vacuum to suck out the clog from the drain line's outdoor end.
- Flush the line with a vinegar or bleach solution to prevent future buildup.
2. Dirty or Frozen Evaporator CoilA dirty evaporator coil can cause ice to form on the coil. When the system turns off or warms up, the ice melts quickly, producing excess water that the drain pan can’t handle.
Causes of freezing:
- Dirty air filter restricting airflow
- Low refrigerant levels
- Dirty evaporator coil
- Ice buildup on the coil
- Reduced cooling performance
- Water puddles near the unit after shutoff
- Turn off the AC and allow the coil to thaw completely.
- Replace the air filter.
- Call a technician to clean the coil or check refrigerant levels.
3. Damaged or Rusted Drain PanThe drain pan beneath the evaporator coil collects water as it drips off the coil. If the pan is rusted, cracked, or corroded, water may leak before reaching the drain line.
Signs:
- Water dripping directly from the bottom of the unit
- Visible cracks or rust in the pan
- Temporarily seal small cracks with epoxy or sealant.
- For permanent fixes, replace the drain pan.
4. Disconnected or Improperly Installed Drain LineIf the drain line becomes disconnected or wasn't installed securely, it can cause immediate leaking whenever the system runs.
Signs:
- Water dripping only when the AC is on
- Water flowing freely from the line connection
- Reconnect the line properly and secure it with appropriate fittings.
- Ensure the line has a proper slope toward the drainage point.
5. Low Refrigerant LevelsWhen refrigerant is low (due to a leak or improper charge), the evaporator coil can get too cold and freeze over. As with dirty coils, the thawed ice can overwhelm the drainage system.
Signs:
- Hissing or bubbling sound
- Poor cooling performance
- Ice on refrigerant lines
- Have a certified HVAC technician inspect for leaks and recharge the system.
6. Blocked or Dirty Air FilterA dirty filter restricts airflow, which causes the coil to get too cold and freeze. This can lead to excess condensation when the ice melts.
Signs:
- Reduced airflow from vents
- Ice forming on coil or lines
- Short cycling
- Replace the air filter monthly or as recommended (usually every 1–3 months).
- Always use the correct size and MERV rating.
7. High Humidity LevelsIn climates with very high humidity, the volume of moisture in the air can overwhelm even a well-functioning AC system’s ability to drain water fast enough.
Signs:
- Water leaks even when everything seems clean
- AC runs continuously without cycling off
- Install a condensate pump if drainage is too slow.
- Use a dehumidifier in tandem with your AC to reduce indoor humidity.
8. Improper Installation or SizingIf your air conditioner is too large for your space or was installed incorrectly, it might short cycle or fail to remove enough humidity, leading to condensation problems.
Signs:
- Water leaks despite regular maintenance
- Temperature swings and poor humidity control
- High energy bills
- Have an HVAC contractor check if your system is correctly sized.
- Ensure that ductwork and tilt angles are appropriate.
What to Do If Your Air Conditioner Is Leaking Water
- Turn off the AC to prevent further damage or water accumulation.
- Check the air filter and replace it if dirty.
- Inspect the drain line for visible clogs or disconnections.
- Use a shop vac on the outside drain line to clear blockages.
- Empty and dry the drain pan if it has standing water.
- Call a technician if the issue persists or involves refrigerant, freezing, or electrical components.
How to Prevent AC Water Leaks in the Future
- Replace air filters regularly (every 1–3 months)
- Flush the condensate drain line every 3–6 months with a vinegar solution
- Schedule annual HVAC maintenance to inspect coils, refrigerant levels, and drainage
- Install a float switch to automatically shut off the AC if the drain pan overflows
- Use a secondary drain pan under attic units for extra protection
- Keep surrounding areas clean to avoid debris getting into the system
When Is a Leak an Emergency?If your air conditioner is leaking water near electrical components, soaking ceilings or walls, or causing visible mold growth, turn off the unit and call a professional immediately. Water damage can quickly become a much bigger (and more expensive) problem
While a little condensation is normal, your air conditioner should never visibly leak water inside your home. Most water-dripping issues stem from clogged drain lines, dirty coils, or neglected maintenance--but they can be fixed relatively easily if caught early.
Regular care and attention to your system can prevent leaks, protect your property, and keep your home comfortable all year round. If you’re unsure about the source of the leak or don’t feel comfortable handling it yourself, don’t hesitate to contact an HVAC professional.