Why Does My AC Unit Freeze Up and What to Do?

Why Does My AC Unit Freeze Up and What to Do?

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An AC in summer months is a true lifesaver, but what happens when it starts acting up by freezing? Such a situation can both disrupt your comfortable atmosphere and significantly damage the conditioner. Today, we at Airmaker HVAC Inc. answer the question, “Why does an AC freeze up?” and figure out what causes AC to freeze up in summer and what you can do with it.

Check for Warning Signs of Air Conditioner Problems

Although they might seem rare, AC issues are more common than many people think. They almost never come unasked for, meaning that you can always find a deeper cause that leads to your AC unit freezing up. Let’s take a look at some red flags that can symbolize that your AC is struggling:

  1. Reduced Airflow: Weak or uneven flow of air is one of the leading indicators of AC unit malfunctioning. Keep an eye on it, and contact a specialized technician once you notice issues with the airflow.
  2. Unusual Noises: Like with any appliance, you never want your AC to start making unusual noises. If you have noticed banging, grinding, screeching, or unusual humming, make sure to address it immediately.
  3. Ice Buildup: AC freezing up often manifests in ice building up on the air vents or the coils.

Main Reasons Why Your Air Conditioner Freezes Up

Once you notice any of the earliest signs, it's crucial to address them promptly so as not to allow your air conditioning unit to freeze up completely. Still, you might still be asking yourself, “Why does my AC unit freeze up at all?” While it is hard to give a comprehensive answer right away, there are a few significant sources of the issue:

Dirty Evaporator Coils

One of the most crucial components of any AC unit, evaporator coils are responsible for absorbing the heat from the air indoors, effectively cooling it down. However, besides the heat, they can also absorb dirt, dust, grime, fur, and other debris, which can clog them. As a result, the air conditioner coils can’t absorb heat anymore, making them colder than intended and causing ice to build up on their surface.

The best way to avoid it is to schedule professional cleaning by a qualified technician, which we offer at Airmaker HVAC, Inc. This allows to remove all the dirt, dust, and grime from the coils safely, restoring their heat absorption capabilities.

Clogged Air Filters

Another AC element that tends to get clogged with time is air cleaning filters. They clean up the air that circulates in the system, stopping external pollutants from getting into your house. If not taken care of or replaced regularly, they also might get blocked, which prevents proper airflow and stops the cold air produced by the coils from circulating in your home. This situation also forces the evaporator coil to become colder than necessary, potentially causing the AC freezing up.

To avoid the risk, you try replacing the clogged air conditioner filter with a clean one according to the manufacturer’s guidance. In addition to that, you should consider choosing higher-quality MERV-rated advanced filters for better dust capture.

Low Refrigerant Level

Refrigerant is the lifeblood of all AC systems, and this is what sets them apart from regular air fans. It absorbs the heat from the air indoors, which is a vital element in cooling it down. If the level of refrigerant gets too low, it can lead to a decrease in the system's ability to absorb heat, causing the evaporator coil to overwork and sometimes freeze.

Don't try fixing everything yourself! Adding cold refrigerant requires specialized training and equipment. Contact Airmaker HVAC Inc. for a professional refrigerant leak detection and recharge service.

Damaged Blower Fan

While all the other elements play vital roles in processing and filtering the air, the blower fan circulates it across the evaporator coil. Therefore, it is crucial for it to work correctly because if it is damaged, it won’t be able to pull enough air across the coils. Just like with the clogged AC filters, it often results in reduced airflow and the evaporator coil freezing.

This requires professional attention. A technician from Airmaker HVAC Inc. can diagnose the problem and recommend repair or replacement of the blower fan motor or blades.

Damaged Ventilation Ducts

Another way that the airflow can be obstructed is by issues with the air ducts, which can be leaking, blocked, or entirely collapsed. The results are similar to a damaged blower fan or a dirty air filter, often causing the evaporator coil to freeze.

Schedule an airflow inspection by Airmaker HVAC Inc. We can identify any leaks, blockages, or collapsed sections in the ducts and recommend repairs or replacements.

Clogged Condensate Drain Line

All the heat absorption and cooling processes generate a lot of moisture, which needs to go somewhere, which is what the condensate drain line is responsible for. If it gets clogged or doesn't work in any other way, the condensate can back up and freeze on the coils.

A technician can clear the clog using specialized tools. Airmaker HVAC Inc. can also check for proper drainage and ensure the condensate trap is functioning correctly.

Levels of the Thermostat

If all the air conditioning components of are working properly, but the AC keeps freezing, it may be because of inadequate thermostat settings. If the setting is too low there, it will force the conditioner to run for extended periods. It can potentially overload the coils and cause them and the whole AC to freeze.

Adjust your thermostat to a comfortable setting. Avoid setting it excessively low. Consider using a programmable option to optimize cooling cycles and prevent the AC from running constantly.

Other Potential Causes

While less common, other factors like a flawed controller, failing sensors, or a faulty compressor could also contribute to the central air freezing up.

If you suspect any of the aforementioned red flags, contact Airmaker HVAC Inc. for a professional diagnosis and repair. They have the expertise to identify the specific issue and recommend the best course of action.

How to Prevent an Air Conditioner System From Getting Frozen

Now that we have figured out all the signs and causes, let’s delve into how to stop AC freezing up in hot weather when it is crucial to keep it running for a long time. Let’s take a look at some of the best ways to stop your AC unit freezing up in summer:

Schedule Regular Maintenance

We recommend scheduling professional maintenance and inspection to prevent any AC damage. Ideally, it should be done twice a year (in spring, before the hot season, and in fall, after it). At Airmaker HVAC, Inc., we are always happy to provide you with the services of the most qualified technicians who can help identify and remove the problem as soon as it arises. During the maintenance, the technician will clean the dirty coil, check refrigerant levels, and ensure all components are functioning correctly.

Change Air Filters Regularly

The air filter must be replaced regularly, according to the manufacturer's recommendations. However, if you have pets or live in a dusty environment, it should be done more often as the filters get clogged faster. Doing this will ensure adequate airflow and prevent the evaporator coil from getting clogged.

Maintain Proper Thermostat Settings

Set your thermostat to a comfortable temperature and avoid setting it excessively low. Turning it down a few degrees for short periods is more efficient than constantly running the AC at extreme settings.

Keep Vents Open

One of the common reasons for AC freezing is that the vents are obstructed by furniture, plants, or something else. Make sure there is nothing in the way of the proper airflow of your conditioner to prevent it from freezing and other ways of malfunctioning.

Schedule Duct Inspections

Besides the general maintenance, it is necessary to also schedule an airflow inspection of the ducts specifically. This way, you will be able to identify any duct leak, blockage, or other signs of deterioration before they turn into more significant issues.

Frequently Asked Questions

What Happens if You Keep Running a Frozen AC? 

Running frozen air conditioners is a big no-no! Here's why:

  • Ice Buildup Damage: As the ice melts and refreezes repeatedly, it can damage the evaporator coil fins and other components.
  • Damaged AC Compressor: The AC compressor is the heart of the whole central air conditioning system, and it's very expensive to repair or replace. When the evaporator coil freezes, refrigerant flow is restricted, forcing the compressor to work harder. This extra strain can lead to compressor failure.
  • Reduced Efficiency: A frozen conditioner struggles to cool your home effectively. This not only reduces comfort but also leads to wasted energy and higher electricity bills.

Can an Overworked AC Freeze Up?

Yes, an overworked air conditioning unit is more susceptible to freezing. Here's how:

  • High Outside Temperatures: During extreme weather, your AC needs to work harder to maintain the desired temperature. This increased workload can lead to the evaporator coil becoming too cold and freezing over if other factors, like the accumulation of dirt on the filters or refrigerant issues, are present.
  • Blocked Airflow: Poor airflow due to clogged filters, closed vents, or damaged AC ducts can prevent the AC from properly removing heat from the home. This forces the evaporator coil to work harder, potentially leading to freezing

Will Low Freon Level Damage a Compressor? 

Low refrigerant (Freon) levels can definitely damage your compressor. Here's why:

  • Increased Strain: The compressor has to work harder to circulate the limited amount of refrigerant available. This extra strain can lead to overheating and eventual compressor failure.
  • Starved for Coolant: When refrigerant levels are low, the air conditioning system has less coolant available to absorb heat. This causes the evaporator coil to become colder and potentially freeze.

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