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Why Your AC is Freezing Up & What to Do

If there’s one thing we know all too well here in Ohio and Indiana, it’s just how crucial our air conditioning systems are for surviving the sweltering summer months. 

So, imagine that it’s the height of summer, and you’re relying on your trusty air conditioner to keep you and your family cool and comfortable… But then, you notice something’s off. There’s hardly any airflow coming through the vents, and what little air there is feels like you’re getting hit with an ice blast! Before you know it, your once crisp, chilled living space is taking on a distinctly frosty chill.

What’s going on? Your poor AC unit is literally freezing up and struggling to do its one job—providing blessed cooling relief. This “frozen confection” situation is actually one of the more common midsummer AC ailments.

Don’t panic just yet! A frozen AC doesn’t necessarily mean your system is on its way out. More often than not, it’s usually just a symptom cropping up due to another underlying issue. Much like going to the doctor for a fever, finding and treating that root cause gets your household cooling back on track.

In this post, we’ll explore some of the most frequent reasons why air conditioners ice up. From poor airflow and drainage problems to electrical issues and low refrigerant levels, there are several potential culprits at play. We’ll break down how to identify which one might be freezing your AC into a block of ice. 

More importantly, you’ll learn some simple DIY solutions for addressing these problems, as well as guidance on when it’s wisest to wave the white flag and call in professional reinforcements before things get too chilled.

So grab a sweater (you’ll probably need it!) and let’s dig into why your AC has turned frosty—and how to defrost the situation before your home turns into an igloo.

Understanding How Your AC Works

Before we discuss why ACs sometimes freeze up, it’s important to understand the basics of how these systems work to keep your home cool and comfortable. Having some background knowledge on the key components involved and the cooling process will help you better troubleshoot any icy issues that arise.

Basic Components

At the heart of your central air conditioning system are just a few main pieces of equipment that facilitate cooling:

Evaporator Coil: This is the indoor coil where the air actually gets cooled. Refrigerant circulates through the coil, absorbing heat and moisture from the air passing over its surface.

Condenser Coil: Located outside, the condenser coil expels the heat absorbed by the refrigerant inside, allowing it to condense back into a liquid state.

Refrigerant: This chemical compound can readily convert between liquid and gaseous states, enabling it to transfer heat out of your home.

Thermostat: The thermostat monitors indoor temperatures and signals the system to turn on or off based on your desired cooling settings.

Blower Fan: Fans help pull warm air from your home over the indoor coil while also expelling hot air from the outdoor condenser unit.

The Cooling Process

Here’s a simple breakdown of how these components work together in the refrigeration cycle to cool your home’s air:

  1. The refrigerant enters the indoor evaporator coil as a cool liquid. Warm interior air blows across the coil, causing the refrigerant to absorb heat and moisture from that air.
  2. Now carrying heat from inside, the refrigerant travels outside as a hot gas into the condenser coil. A fan blows air across this coil, allowing the refrigerant to shed its heat outdoors.
  3. The refrigerant condenses back into a liquid after releasing its heat outside. It gets pumped by a compressor back indoors to continue repeating the cycle.

When operating properly, this continuous cycle produces a steady flow of dehumidified, cooled air circulating from the vents and keeping your home comfortable. However, if something causes the evaporator coil to freeze over, it disrupts the entire cooling process.

Now that we’ve covered some cooling basics, we can look at the reasons why frozen evaporator coils occur and how to resolve this problem effectively. The goal is to get your AC running smoothly again so it can provide reliable cooling relief.

Common Causes of AC Freezing

While a frozen air conditioner may seem like a major, complicated issue, it often stems from relatively simple root causes that can be identified and resolved. Understanding what might be triggering your system to ice over puts you one step closer to restoring cool, comfortable airflow throughout your home. 

Let’s go over some of the most common culprits behind this icy situation.

Insufficient Airflow

Proper airflow over the indoor evaporator coil is essential for your AC to absorb heat effectively. When airflow is restricted, it can cause the coil to get too cold and freeze over condensation.

Clogged Air Filters: As your system runs, dust and airborne particles gradually build up on the air filters over weeks and months. Eventually, this buildup becomes so caked on that air has difficulty flowing through, starving the evaporator coil of warm air passing over it.

Blocked Vents and Registers: Furniture, rugs, toys, or other household items obstructing the supply vents or return air registers prevents air from circulating freely into and out of the system. This lack of airflow impacts the coil’s heat absorption.

Low Refrigerant Levels

Refrigerant is the liquid catalyst that facilitates your AC’s heat transfer process. When levels run low, it inhibits the evaporator coil’s ability to absorb heat properly, causing freezing.

Refrigerant Leaks: Over years of operation, small pinhole leaks can develop in the copper tubing or connections, allowing refrigerant to escape the closed system slowly over time.

Improper Charging: Having too little or too much refrigerant charged into the system upsets the balance of pressures and flow rates needed for efficient cooling and heat absorption.

Thermostat Issues

The way you set and maintain your thermostat plays a bigger role than you might realize in preventing coil freezing issues.

Improper Settings: Setting your thermostat to an extremely low temperature below 65°F essentially causes the AC to run continuously without cycling off. This allows the evaporator coil’s temperature to drop too low and accumulate frozen condensation.

Malfunctioning Thermostat: A thermostat not functioning correctly due to dead batteries, electrical issues, or other failures can prevent it from accurately reading temperatures or cycling the system on and off as intended.

Mechanical Failures

Certain AC system components themselves can contribute to freezing problems if they fail or wear out over time.

Blower Fan Problems: If the fan responsible for circulating air over the indoor evaporator coil fails or cannot operate at full speed, it reduces airflow across the coil surface, allowing ice buildup.

Dirty Evaporator Coils: When the indoor coil gets heavily insulated with built-up dust, dirt and grime, it acts as insulation preventing proper heat absorption from the air. This causes condensation to freeze on the cold coil instead of being absorbed as intended.

Immediate Steps to Take When Your AC Freezes

You’re relaxing at home when you notice something isn’t quite right with your air conditioning. The vents don’t seem to be pushing out much cool air anymore. In fact, you can almost feel a frosty chill coming from the indoor unit itself. 

A frozen AC – those are the telltale signs. As frustrating as it is, it’s important to take some immediate steps to prevent any bigger problems down the line and get that refreshing cooling flow restored.

Turning Off the System

First thing’s first – turn off your air conditioner entirely. I know, I know – that’s the last thing you want to do when you need cooling the most. But allowing the system to keep running when it’s frozen up is just going to compound issues. 

Locate your thermostat and switch the cooling mode to the “off” setting. If you can’t get to the thermostat, you can also shut things down using the disconnect box mounted near the outdoor condenser unit.

Kicking on Fan Mode

With the AC no longer trying to cool, go ahead and switch your thermostat over to run just the indoor fan. This allows air to circulate over those frozen coils without the compressor kicking in. 

Keeping that air moving gradually melts away any ice buildup on the refrigerant lines and evaporator coil. It may take some time, but a little fan-powered thawing is way better than forcing that ice through the system.

Checking the Air Filter

While you’re waiting on the fan to work its defrosting magic, take a look at your air filter. We’re all guilty of letting these get gunked up over time, restricting airflow and potentially causing those coils to freeze up in the first place. 

If you can’t remember the last time it was replaced, chances are it needs a fresh new filter to get air flowing freely again.

Clearing Any Obstructions

It’s also a good idea to do a quick scan of all the vents and returns throughout your home. Make sure no rugs, furniture, curtains or other household items are blocking that airflow. You want to ensure there’s an unobstructed path for air to both enter and exit the system once you power things back up.

Give that fan at least 24 hours or so to fully defrost all the icy buildup before attempting to restart your AC in cooling mode. If heavy icing persists or quickly returns after restarting, chances are there’s an underlying issue you’ll need professional help sorting out. But taking these initial thawing steps buys you some time and may just kick that cooling flow back into gear!

Long-Term Solutions to Prevent AC Freezing

Once you’ve got your air conditioning back up after wrestling with a frozen episode, it’s smart to look at more permanent measures to prevent that icy ordeal from happening again. While the temporary steps get your home cool for now, implementing some longer-lasting solutions helps tackle those root causes moving forward.

Stay On Top of Maintenance

Regular Professional Tune-Ups: There’s no substitute for having a certified HVAC pro thoroughly inspect and service your system at least once a year. They’ll clean coils, check refrigerant levels, tighten electrical connections, and more – all the little things that mean efficient, freeze-free operation when optimized.

DIY Upkeep: But you don’t have to wait for the experts in between visits. Simple homeowner tasks like swapping air filters routinely, clearing yard debris around outdoor units, and keeping vents open maximize airflow to reduce icing risks. Just avoid any refrigerant handling or wiring work best left to the professionals.

Consider a Thermostat Upgrade

Programmable Models: That old manual dial thermostat may be due for a modern replacement. Programmable digital thermostats allow much smarter temperature management to keep your AC from running excessively and freezing over. Customizable schedules and settings help balance comfort and efficiency.

Smart, Connected Thermostats: Want to take it a step further? Smart wifi thermostats actually “learn” your household rhythms to make micro-adjustments that maintain ideal cooling settings. Some even send mobile alerts about problems like frozen coils so you can troubleshoot faster.

Improve Insulation and Sealing

Plug Air Leaks: All those tiny drafty cracks and gaps around windows, doors and your home’s exterior create cooling loss and interior temperature fluctuations that strain your AC system. Caulking and weatherstripping leaks reduce those unwanted temperature swings.

Enhance Overall Insulation: On a bigger scale, upgrading insulation in attics and exterior walls just makes better sense for consistent temperature control. Well-insulated homes allow ACs to run without the cooling extremes that lead to frozen coil issues.

Install a Dehumidifier

Standalone Units: Let’s face it – battling our region’s soupy summer humidity is often the core reason ACs ice up as excess moisture condenses on refrigerant lines. A portable or whole-home dehumidifier extracts that moisture before it causes buildup.

Integrated Systems: For seamless control, you can also opt for a dehumidifier integrated directly into your central HVAC system. These remove excess humidity at the same time the AC is operating for balanced temperature and moisture.

While frozen air conditioners are certainly a summer headache no one wants, the hassle often reveals an underlying need for your home’s cooling system to get a little more TLC. Making maintenance and upgrades a priority provides season after season of cool, dry, comfortable air without any frosty interruptions.

When to Call a Professional

As much as we may want to handle our air conditioning problems ourselves, there comes a point where the problem is just too complex and is beyond the scope of our DIY abilities… and there’s no shame in that! Knowing when to wave the white flag and call in the experts could actually save your system from further damage and give you relief faster.

But when should you make that call? We have listed a few key indicators that should tip you off that it’s time to make that service call:

Your Fixes Aren’t Sticking

Maybe you’ve meticulously followed all the recommended steps to defrost and restart your frozen AC unit – turning the unit off, running just the fan mode, replacing air filters, and clearing obstructions. But despite your diligent efforts, those pesky freezing issues keep coming right back.

When the standard homeowner remedies fail to create lasting relief, that’s usually a sign of a deeper underlying fault requiring professional-level diagnosis and repair.

Strange Sights and Sounds

Does your AC make any concerning noises while running – grinding, squeaking, or knocking sounds from the indoor or outdoor units? Or perhaps you’ve noticed other alarming symptoms like smoke, burning smells, or exposed wiring in disrepair. Those are definitely situations where it’s wise to step away and call in the trained experts.

Continuing to operate equipment exhibiting those types of mechanical or electrical red flags could potentially make problems far worse.

You’re Simply Stumped

Even after thoroughly inspecting your system yourself, and checking all the typical culprits, if you simply cannot pinpoint the root cause for why your AC keeps freezing up, then it’s time to call in some certified HVAC technicians. They bring years of specialized training and experience to properly diagnose even the most baffling air conditioning system behaviors. Rather than potentially causing more damage through misguided repair efforts, it’s best to get the experts involved at that point.

HVAC systems are complex appliances and issues with one component can create a ripple effect of problems across the entire air conditioning system. While basic homeowner maintenance is always advised, knowing your limitations and bringing in professional support when needed ensures your cooling system gets properly serviced and protected for years to come.

Regaining Cool Comfort with Bassett Services

There you have it, folks – the scoop on why your AC might be pulling a frosty performance this summer and some tips for getting that cool air flowing again. While a little ice can seem frightful, try not to get too frozen with fear. More times than not, a straightforward fix or repair can get that refreshing air flowing again.

But if you’ve attempted the recommendations and your AC still can’t shake the ice, don’t feel like you’re out in the cold alone. Our experienced professionals at Bassett Services are ready to ride to the rescue. Our experts have the knowledge to get to the bottom of what’s causing that frozen frustration. We’ll make sure the real culprit gets fixed up right, so your home transforms back into that oasis of calm cooling you crave.

Delivering stellar service that keeps customers smiling is what drives the Bassett Services crew. We’ll stick with it until your AC unit is fine-tuned and ready to take on the hottest summer stretches still ahead. Don’t delay any longer – pick up that phone and ring us at (317) 360-0054 to line up an appointment time.

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