If your air conditioner is going to have a refrigerant leak, there’s a good chance it will happen on the indoor coil.

Also known as the evaporator coil, this air conditioner component lives inside your HVAC system’s indoor unit. Refrigerant passes through it. Air passes over it. Heat is removed from your home, and you feel great all through August.

Until it starts to leak.

When you’ve got an indoor coil that’s leaking refrigerant, it will take a long time for the system to cool your home… if it cools your home at all. Even if your AC doesn’t quit right away, you’ll experience longer run times.

As the leak worsens, the system will lose its ability to cool.

There’s no reliable way to repair the leaks themselves. Evaporator coils are large components that reside in dark places and are characterized by tiny dips, curves, crevices, and hard-to-see, hard-to-reach areas. When it comes to finding leaks, the needle-in-a-haystack analogy applies.

And keep in mind that you might be dealing with several little leaks, not just one big obvious one.

For this reason, you’ll usually have to replace your coil, your air handler, or your entire HVAC system. It all depends on what kind of system you’ve got, how old it is, and your long-term priorities for heating and cooling.

Your decision depends on what type of system you’ve got today and the level of comfort and efficiency you’d like to enjoy in the future.

And if you’re reading this article breathing a sigh of relief that you’ve never had a leaky evaporator coil, know this: It can happen to you. That doesn’t mean it’ll happen this summer, next summer, or the summer after that. But it’s always possible.

Now that you know what to do, you can make a confident decision that resolves the problem as quickly as possible.