How to Fix an AC that Keeps Freezing Up

It is not unusual for air conditioners to have faults and act up from time to time. Some of these faults are so minuscule, and they tend to either be ignored or completely unnoticeable. But there are some problems that can’t be ignored and will definitely demand attention. One such fault is a frozen AC unit. 

air conditioner

This is when AC coils or any equipment or panel of the AC is literally covered in ice. It is easy to fix it, but it could be quite problematic for the owner when it keeps on happening. If this is the first time you are seeing or knowing about it, it can be disturbing and frightening even; if you have heard about this before, you are likely not as stunned, which leaves us to the next question.

Why Does My AC Keep Freezing Up?

There are a lot reasons why your AC may keep getting frozen, but these are the most common ones:

  • Dirty or clogged air filters
  • Dirty or collapsed air ducts
  • Faulty blower fan
  • Faulty refrigerator
  • Clogged condensate drain line
  • Bent condenser fins
  • Freezing temperatures

1. Dirty Or Clogged Air Filters

A dirty air filter is the first and most common cause of a frozen AC unit. The air filter is responsible for catching, trapping, and blocking dust, pollen, debris, and any other kind of air pollutants from entering your home. 

If you use your AC unit regularly, it is only natural for the air filter to get clogged up from debris collection over time. When that happens, the filters start to restrict airflow, and the condensed air will start freezing on top of the filter and evaporator coil instead of dripping into the pan designed for it. 

2. Dirty Or Collapsed Air Ducts

Another thing that could potentially cause your AC unit to freeze up is a clogged air duct. The air ducts work hand in hand with the air filters by helping to circulate air throughout the house. If there is an imbalance or insufficiency in airflow, then the AC won’t work correctly, and the extraction or exchange of hot air to cool one won’t happen correctly. The consequence is a frozen evaporator coil. 

Note this, though. Sometimes the air ducts are not clogged, they are just leaking. So, check thoroughly to make sure you know the exact problem it has. It could be one or maybe both.

3. Faulty Blower Fan 

The blower fan or air conditioner blower’s job is to remove warm air or heat from a room and replace it with a cold one. It is a key component of an AC unit, and it maximizes airflow for better circulation in a room. If it doesn’t work well and has any sort of fault, it will disrupt airflow, leading to a buildup of condensed air that will freeze on top of the coils.

4. Faulty Refrigerator

There are two main refrigerator problems that could cause your AC unit to freeze; one is a leaky refrigerator and the second one is a refrigerator with low refrigerant levels. One of the ways to recognize a faulty refrigerator is by checking where the ice is forming precisely. If it is forming on the sides of the condensers panels, then you clearly have a faulty refrigerator. 

What happens is, because of the low refrigerant levels or lack of one, the AC won’t work properly anymore, and the reduction in pressure will cause water vapor to freeze on the surface of the coil or panel. 

5. Clogged Condensate Drain Line 

We have mentioned how an AC unit works earlier, but we will explain it again to help you fully understand this. The AC unit works by transferring heat produced in your home outside and bringing in cold air. The moisture extracted from the humidity of the hot air goes through condensation that drips into a pan and goes out of your home.

The pipe it passes through is the condensate drain line. 

It is common knowledge that water breeds germs. Over time, the dripping water will breed germs inside the pipe, and it will collect mold and other types and water pollutants, get clogged, and soon enough, there won’t be space for the water to pass through. 

This will cause the drip pan to get overfilled and then begin to freeze on the tray and over the evaporator coils. 

6. Bent Condenser Fins

The condenser fins are metal-type things that cover the walls of the condenser unit in your AC. Sometimes they get bent, and if not folded back to their original position, they could also cause your AC to freeze up. 

7. Freezing Temperatures

Typically, no one would be willing or daring enough to put on an AC when the weather is cold, but there are some people who for some reason find it convenient – cue internal scream – and we are here to say don’t. 

Please don’t do it. Your AC will turn into an icebox.

Putting on your AC when the temperature is below a certain degree will cause the pressure inside it to drop. Air conditioners generally cool the air 18 to 20 degrees lower than the temperature you set it to. If this happens during extremely cold weather, the condensation will cause your AC to freeze.

Now that you know the possible causes let us look at how to fix them.

How Do You Fix A Frozen AC?

If you’ve read our article on the reasons why your furnace won’t come on, you will notice a similar pattern in both articles. When any part or component or equipment of a heating device or air conditioner gets dirty, it will lead to a variety of problems or stop working efficiently.

For your air conditioner, the simple solution is to check, clean, and regularly change the air filters, air ducts, condensate drain lines, and refrigerators or refrigerants. Doing this will help your air conditioner last longer, save you the stress and cost of fixing faults yearly. But this is a long-term solution.

An immediate solution is to turn off the air conditioner, cut all power supplies connected to it and let the ice thaw. A few thawing rules before we continue:

  • Do not use heat.
  • Do not pour hot water on it.
  • Don’t try to break the ice with your hands or a hammer.

Now that we are clear on that, what you can do is turn on the blower fan and let it thaw the ice by itself. Or you can wait for a few hours for the air to thaw it naturally. After that, you can see what exactly caused the freezing in the first place.

If it is something that needs to be changed, do the needful, but if it is a more technical problem, you may have to call an HVAC professional. Luckily, there are so many available, place a call through and book an appointment.