You’ve reached the hottest days of summer, and your home AC unit is cranking. But when you go outside, you notice a cause for alarm. Water is pooling around your AC unit.
Is that normal, you think? My air conditioning shouldn’t be leaking water, right?
The truth is: An HVAC leak is a common issue. In fact, according to Popular Mechanics, about 90 percent of HVAC service calls are due to leaks. Fortunately, the majority of leaks can be remedied quickly and at a low cost.
But it’s important that the problem is fixed as soon as you notice it. Leaking water can seep into your home AC unit, causing extensive damage that may require the unit to be replaced. In other words, if you notice a leak, call an HVAC company.
What’s Creating the Water in My AC Unit?
Residential air conditioners all feature the same components. Outside, you have a condenser unit, which looks like a large boxed-in fan. Inside, there’s another unit that contains evaporator coils.
The refrigerant flows through the coil, and when warm air passes over these chilled coils, the air temperature drops significantly. This ultimately is the air that flows through your ductwork and cools your home.
But the evaporator coils also accumulate condensation, just like a glass of ice water on a hot day. It’s completely natural for the coils to “sweat,” and there’s a system in place to ensure this condensation drains from the system.
From the coils, the condensation drops into an overflow pan and then flows into a condensate drain line. This either connects into your plumbing or drains out of the house. Some homes also require a pump to send water away from the system.
Most commonly, the cause of the leak has to do with this condensation not properly draining, or too much of it being produced.
Common Causes of Leaking AC Units
- A Cracked or Clogged Drain Pan
- A Damaged or Clogged Condensate Line
- A Faulty Condensate Drain Pump
- A Dirty AC Filter
- Low Refrigerant
- Low Outside Temperatures
Over time, your AC’s drain pan can become damaged. For example, if your AC is reaching the limit of its service life, the drain pan may have become corroded and rusted through. As such, water drains freely through the pan and begins to pool underneath. Replacing the drain pan can remedy the issue.
Additionally, algae, dust, and debris can also collect in the pan, effectively clogging the drain hole. In this case, cleaning the pan may resolve the issue.
If the pan is clear, the condensate line itself may be clogged. Typically, condensate lines are built with PVC pipe, and when clogged, they can back up water. Water begins to collect within the pipe and drain pan, and ultimately the system can properly drain. Flushing the condensate pipe can resolve the clog. Additionally, a cracked pipe can also leak water, which may be the source of the issue.
Finally, if your home uses a drain pump, there’s a chance that it’s not working properly. This ultimately backs up the entire condensate draining system. In this case, the pump would need to be replaced.
Dirty AC filters can cause a range of issues. That’s why it’s important to schedule yearly and seasonal maintenance for your home AC. Why does a dirty filter cause leaks? A dirty filter can freeze up the evaporator coils. When the coils thaw, they produce too much water for the drain pan to handle.
An AC without enough refrigerant can cause a number of issues. Most noticeably, the system won’t cool as effectively. But like the dirty filter, the low refrigerant can also cause the coils to freeze, which will overflow the pan after it thaws.
Late in the summer, and in early fall, temperatures tend to fluctuate more dramatically. Running your AC in cool weather – low 60s and cooler – the coil block can freeze. Again, after it thaws, your drain may overflow.
Solving a Home AC Leak
As you can see, the cause of your leaking air conditioning might not be as serious as you think. Replacing a drain pan, line or pump, or the AC’s air filter doesn’t require a significant investment, and it can ensure your AC keeps running in tip-top shape.
The key though is catching these issues early. During the cooling season, regularly inspect your home’s AC unit. A small amount of water is normal, but if you notice a lot of water pooling up underneath, you might have a problem. In this case, it’s best to call an HVAC company to have a look.