Noticed your air conditioning unit dripping water? It’s a common concern that many homeowners face, especially during the warmer months when your system is working harder. While a small amount of condensation is normal, excessive dripping or pooling water inside or outside your unit is a sign that something isn’t quite right.
In this article, we’ll explore the most common reasons why air conditioning units leak water, how to prevent it, and when to call in a professional.
Is It Normal for an Air Conditioner to Leak Water?
A small amount of water drainage is a normal part of how your split system air conditioner operates, however, the water is caught by a pan within the aircon. These systems work by removing heat and moisture from the air inside your home. As warm air passes over the cold evaporator coil, moisture in the air condenses into water droplets. This water then collects in a drain pan and is safely channelled away through a condensate drain line.
However, while a little water is expected, visible leaking where it shouldn’t be is not. If you notice water dripping from the indoor unit, pooling around the system, or seeping into walls or ceilings, it may be a sign of a more serious issue.
Common causes of abnormal water leaks include a blocked or cracked drain line, a full or misaligned drain pan, dirty air filters reducing airflow, low refrigerant levels, or problems with installation and insulation. These issues can affect the internal components, leading to malfunctions or leaks. In colder conditions, ice formation on the coil (followed by melting) can also lead to excess water leaks.
If your split system air conditioner is leaking water excessively or from unusual places, it’s important to arrange an inspection by a qualified aircon technician. Prolonged water leakage can result in significant damage to the air conditioning system, necessitating expensive repairs or replacement.
Common Reasons for an Air Conditioning Leak
If your air conditioner is leaking water, it is important to investigate the cause quickly to prevent damage to your home and ensure your system continues running efficiently. Seeking professional help to diagnose and fix the issue can prevent costly repairs. Here are some of the most common reasons for water leakage:
1. Blocked Condensate Drain Line
This is one of the most frequent causes of water leaks. Over time, dust, dirt, mould, algae, or other debris can build up inside the condensate drain line. When this line becomes blocked, water cannot drain away as it should. Instead, it backs up and eventually overflows, often dripping from the indoor unit into your home.
Tip: If you notice your air conditioning unit dripping water inside the house, particularly around the indoor head unit, a blocked condensate drain line is a likely culprit. Regular servicing can help prevent this issue.
2. Damaged or Rusted Drain Pan
The drain tray sits beneath the evaporator coil and collects the water that forms during normal cooling operation. However, in older or poorly maintained systems, the pan can rust, crack, or corrode. When this happens, water escapes before it can be properly channelled away, leading to visible leaks.
If your system is more than 10 years old and leaking, it is worth inspecting the drain pan for damage.
3. Dirty Air Filters
A dirty air filter can restrict airflow across the evaporator coil, leading to condensation issues. Without sufficient airflow, the coil can become excessively cold, leading to ice formation. When the ice eventually melts, it produces more water than the system can handle, often resulting in leaks.
Tip: Regularly cleaning or replacing your air filters not only improves efficiency but also helps prevent water leakage.
4. Low Refrigerant Levels
Refrigerant issues can also cause the evaporator coil to become too cold, triggering the same freezing and thawing cycle mentioned above. When ice builds up on the coil and later melts, it can overwhelm the system’s drainage capacity and cause water to leak from the unit.
Bonus: If your air conditioner is struggling to cool your home effectively and you notice water leaks, low refrigerant could be the underlying issue. A qualified technician should check for leaks in the refrigerant lines and recharge the system if necessary.
5. Improper Installation
If the air conditioning system was not installed correctly, several problems can arise that cause water leaks. For example, the unit may not be level, preventing proper drainage, or the drain pipe may not have been securely connected. Poor insulation around pipes can also cause condensation to form where it should not.
Signs of poor installation include persistent leaks, unusual noises, and inconsistent performance. If you suspect your air conditioner was not installed properly, it is best to have it assessed by a licensed air conditioning technician. Only a licensed air conditioning technician can ensure that the installation issues are corrected safely and effectively, preventing further damage and maintaining your warranty.
Why Do Air Conditioning Units Leak Water Inside the House?
If you’ve found water pooling around your indoor unit, it’s likely due to one of the above issues, especially a clogged drain line, frozen coil, or full drain pan. Indoor leaks can lead to significant water damage if not addressed quickly, so it’s important to act fast.
Why Is My Air Conditioning Unit Dripping Water Outside?
Outdoor dripping is usually more normal, particularly on humid days. However, if there’s a sudden increase in volume or continuous dripping, it could indicate a clogged filter or refrigerant problem. Proper maintenance of the air conditioning system ensures a cool home, especially during hot summer months.
How to Prevent Air Conditioning Water Leaks
While some issues may require a professional, there are a few things you can do to help reduce the risk of your air conditioning leaking water:
- Replace or clean your filters every 1–2 months.
- Schedule regular servicing to keep your system running smoothly.
- Inspect for leaks or unusual moisture build-up near your indoor unit.
- Keep the area around the outdoor unit clear to ensure proper drainage and airflow.
When to Call a Professional
Water leaks should never be ignored. If your air conditioning unit is dripping water consistently, or you can’t identify the cause, it’s best to get in touch with a licensed technician.
At Busselton Air, we specialise in diagnosing and repairing air conditioning leaks across the South West. Our experienced team can quickly assess your system, find the fault, and recommend the right fix.