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Iced-Up AC? Here’s Why


Many issues your air conditioner might encounter can cause it to make strange noises. Occasionally, an AC problem will cause strange smells. Much of the time, a problem with your air conditioner will make it less effective, leaving your home either not cool enough overall or uneven in temperature, with some cool spots and some hot ones. But another thing a struggling air conditioner can create is ice!

Ice might not seem like a bad thing. After all, your air conditioner is supposed to make things cold, right? Well, if you’ve got ice building up on your AC evaporator coil, it’s not good. In fact, it will only get worse. Here’s why.

The Evaporator Coil’s Job

The coils of your air conditioner contain refrigerant, and while that refrigerant is flowing through the evaporator coils of the indoor unit, it is evaporating—turning from a super-cold liquid to a heated gas as it absorbs heat from the air of your home. Then, in the condenser coils of the outdoor unit, the heat dissipates, and the refrigerant condenses to a liquid again.

In order to do the job properly, the evaporator coils need heat to soak up, and they need to be able to absorb that heat sufficiently. Otherwise, the refrigerant will stay too cold. The coils will be so cold that when condensation forms on them, it will freeze and become a layer of ice.

The Ice Begins to Form

That first layer of ice means there’s already something wrong. It could be something simple, even something you can remedy yourself. It might be that the evaporator coil was dirty, with a layer of dust and pet hair insulating it so that it wasn’t able to absorb enough heat. It might be that the AC air filter was clogged, so there wasn’t enough warm air being moved past the coil to give it the heat to soak up.

But it might be that you need professional assistance. Another reason the warm air wouldn’t pass by the evaporator coil is if the blower fan motor, or the fan which it powers, is broken. Or, it could be that there isn’t enough refrigerant in the system to soak up the necessary heat. Where did that refrigerant go? It doesn’t get used up in the cooling process, so there must be a leak.

The Ice Keeps Building

Once this process begins, the ice itself acts as a layer of insulation and further prevents heat absorption. That means the problem gets worse, and the ice layers on more thickly! Your AC isn’t able to keep your home cool, the system keeps running more often, your electric bill rises, and your compressor suffers terrible wear. Don’t let this happen!

Address the Ice Right Away

You’ve got to get rid of that ice. Once you’ve turned the AC off, it should melt in less than a day. Check to make sure it doesn’t overflow the condensate pan if it’s melting very quickly! Then you can clean the evaporator coils (gently!) and change the air filter. You should also check that all vents, supply and return, are allowing air to flow freely. Then turn the AC back on. Problem solved? Yay!

If the problem continues, though, and ice develops again, you’ll need the help of a qualified technician for air conditioner repair in Evanston, IL. Whatever the root cause, we’ll find it and get it fixed.

Contact ServiceMax with any questions about your air conditioner.

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