Your air conditioner is one of the most important components to a comfortable home. Without an air conditioner, your summer months would be spent in a hot, humid home.

But sometimes, ACs stop working as well as they used to. Oftentimes, it’s due to a compressor going out, or the motor slowing down, or a refrigerant leak. Refrigerant leaks are one of the more serious problems, as this is not something you can fix on your own. You need a trained professional to address refrigerant leaks.

Refrigerant is made from a noble gas called freon, which has properties that allow it to change state from gas to liquid and back to gas again with the help of the AC unit’s condenser and evaporator. This helps cool down the air that is taken in from the outside. How do you know if your central air needs freon? Here’s some of the telltale signs.

How Can An Air Conditioner Run Out of Freon?

The only way an air conditioner runs out of freon is if there is a leak in the pipes that carry refrigerant from one part of the unit to the other. Freon is not used up: it simply changes state from gas to liquid. Freon should never escape the pipes. However, leaks happen.Leaks can be caused by a variety of factors, however almost all of them are outside of your control.

Formic acid: Formic acid is a corrosive acid that can wear on the copper tubing and cause pinhole leaks. This comes from ants, wasps, and bees, however it can also be caused by formaldehyde turning into formic acid. It’s a naturally occurring acid and there’s no real way to stop it short of continuous preventative maintenance.

Wear and tear: Sometimes, the rubber seals on the service valve can wear down and leak. Sometimes, the assembly joints can rust. This happens over time and will never be seen in a new unit unless it’s defective. If you have an older AC, keep and eye out for this!

How To Know If AC Is Out of Freon

AC is running, but the home isn’t cool

You might feel warm air flowing through the vents, or you might notice that your AC is weaker than it used to be. If air flow seems fine, but the air coming up isn’t cool, then you likely have a refrigerant problem.

Ice buildup on refrigerant line

This happens because the evaporator coil cools down too much, causing cold refrigerant to flow back into the system. This creates low surface temperatures which causes condensed water vapor in the air to freeze.

Do not delay if you see this: it can cause severe damage to your unit. Call your local HVAC technician immediately if you see ice forming on the refrigerant line!

Higher electricity bills

Your thermostat will notice that the temperature inside your home isn’t as cool as it could be, causing it to think that the AC needs to run for a longer period of time. This wastes energy without heating your home. If you notice a spike in electricity bills, it could be a lot of different things, but if you notice it in conjunction with any of these other problems, it’s likely due to your AC unit having low refrigerant.

Hissing or bubbling sound from the refrigerant line

Most freon leaks are silent, however a large leak can be heard from the refrigerant line. It will make a hissing or bubbling sound. If you hear those sounds, call an HVAC technician immediately: this could turn into a problem.