Air Conditioners

How Do I Keep My Air Conditioner from Freezing Up

Air conditioners are an important part of keeping your home comfortable during the summer months. However, if your air conditioner starts freezing up, it can be a real headache. So, you might be asking yourself – ‘how do I keep my air conditioner from freezing up?’

Well, the process starts by shutting off the air conditioner and allowing it to defrost as you troubleshoot the problem. It could be caused by a dirty or a clogged air filter, closed registers, low refrigerant levels, thermostat issues, poor AC drainage, cold summer nights, or a mechanical problem.

A freezing air conditioner is at risk of catastrophic failure, and it can end up consuming more electricity costing you extra money. And the only way to prevent this is by troubleshooting the above causes of the freeze-ups. That way, it’ll be easier to fix it and prevent your unit from freezing up again.

Causes Air Conditioners Freeze Ups (and How to Fix It)

If your air conditioner is starting to freeze up, you’ll likely notice some unusual signs. It may take longer for the unit to cool down, or it might constantly be running with no change in temperature.

You may start to hear odd sounds coming from the condenser unit outside. The air conditioner might start to leak around it or in unusual places because of the ice forming around the unit.

So, what can you do to prevent the problem and prevent the air conditioner from freezing up?

1) Dirty or Clogged Air Filter

For an air conditioner to cool your room properly, there must be good airflow. The air filter cleans the air as it enters the air conditioner or leaves the air condition. It has to pass through freely to prevent the AC from freezing over.

When the dirt accumulates too much to a point the airflow is reduced, there will be less or no air flowing through the evaporator coil, which can eventually develop the freezing.

Even the United States Department of Energy reports that you can improve its efficiency by 5% to 15% if you change your HVAC filter.

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How Do You Fix It?

The best thing here is to clean or change the air filter regularly to prevent freeze-ups and improve indoor air quality and better air-conditioner performance.

But first, turn off the air conditioner and allow it to defrost. Once you’ve given it enough time to thaw, around 1-3 hours, turn the fan mode on and allow it to run for another hour.

Experts recommend replacing the AC air filter one in 3-months, while some manufacturers suggest returning it every month. However, the frequency at which you change the air filter will depend on how long you use the air conditioner and the activities in your home.

If you open the windows often in the spring or early fall, there is a high chance more dust will enter your home. The same will happen if you’ve done some home renovation and repairs.

All these air contaminants can clog up the furnace air filter much faster than usual. So, it’s best to have a monthly schedule check-up of how dirty the air filter is; if it is dirty, clean it, and replace it if too dirty or old.

2) Low Refrigerant Level

The mechanics of an air conditioner depends heavily on the refrigerant flowing through the evaporator coils. It’s responsible for striping the heat from the hot room air and taking it outdoors.

When the refrigerant levels are low, there is a drop in pressure which causes the evaporator coil temperatures to go below the freezing point. And that’s what causes the freeze-ups.

The freezing occurs because of the evaporator coils icing the water vapor on it. At first, it creates a light frost coat, but the frost eventually builds up and creates a thick ice sheet.

And with the refrigerant line being a closed system, the possibility of reducing to detectable levels is low. However, it does happen at times. But, a leak can create a severe low-pressure problem that would need fixing as soon as possible.

How Do You Fix It?

You want first to shut off the unit and start figuring out the next step. I would recommend getting an HVAC professional who understands how to handle a refrigerant. An expert is more than capable of figuring out if the refrigerant lines are leaking or the compressor.

3) Thermostat Issues

The thermostat is another vital component in the air conditioner, which has three main functions. One, it monitors and controls the room temperature. Two, it acts as a relay between the components of your AC to keep them working together in unison. And three, cooling systems with variable speed compressors can control how fast or slow they should work.

When you see your unit running continuously even when you’ve turned it off, there are chances that the thermostat is stuck in the on mode or, worse yet, not detecting any change at all. It will lead to freezing troubles when this happens because everything else will remain working while the compressor stays on.

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How Do You Fix It?

If your problem lies here, you need to quickly check the unit manually and see if this was a common issue. And if it did, how to take care of it yourself or call an HVAC service provider.

4) Poor Drainage

Poor AC drainage is one of the most overlooked causes of freezing issues. But, make no mistake because poor drainage will freeze up your AC darn fast.

You probably know this already, but when water builds up in any part of your heating system, there is a high chance that it’s going to affect its performance or even damage some components. And that’s exactly what happens with air conditioners as well. As soon as the drain gets clogged with dirt and debris, it prevents moisture from escaping, thus causing poor ventilation, which allows water to build up even faster.

What happens next is a short cycle of turning on and off, which creates mist within the system, and this moisture quickly freezes up the evaporator coils, which shuts down your unit.

How Do You Fix It?

An easy way to check for drainage issues is to look behind your outdoor AC, where the condensation drain is located. If it’s clogged, you’ll need an expert plumber who can find out if any other underlying issues could’ve been causing this problem in the first place. You may want someone with experience to clean or replace the condensate pump.

5) Mechanical Problem

If nothing of the above issues is causing the freeze-ups, there may be a mechanical problem, or it’s a sign your air conditioner is going bad.

Air conditioners have lots of moving parts that must stay operational for them to cool your home. However, these parts fail at times by either breaking, clogging, or even getting stuck.

That could cause the fan to stop moving, or there might be another failure causing the unit to malfunction. Whichever the case, it has to be checked and fixed, or it might be time to get a new air conditioner.

How Do You Fix It?

A mechanical problem requires the help of a trained professional who understands how to handle interior parts of an AC. An expert will check and listen to sounds produced by your freezing AC and pinpoint the problem.

I would recommend getting regular tune-ups from HVAC professionals to prevent further catastrophic issues.

6) Cold Summer Nights

Lastly, the air conditioner freeze-ups could be caused by the cold summer nights. With AC units calibrated to operate with particular optimum operating temperatures, the temperatures of the chillier summer nights might go below the optimum threshold your AC can handle. And this can throw it out of what.

How Do You Fix It?

Use a programmable thermostat that can prevent the problem before it starts to manifest. It can help shut down the air conditioner when the temperatures go below the set optimum threshold, about 60 degrees. Also, keep tabs on the outdoor air temperatures; if they drop below 60 degrees Fahrenheit, shut down the air conditioner.

7) Closed Vents or Registers

Some homeowners with an air conditioner in their homes shut the vents and registers for the unoccupied rooms to try and save energy and money. However, closing too many air vents can cost you more to run the AC as it can lead to freeze-ups.

How Do You Fix It?

Start by checking to ensure the vents and registers aren’t blocked if you have not blocked them. If you have, a good rule of thumb for operating an air conditioner is to keep 75% of the home’s air vents and registers open.

Summary: If your air conditioner still freezes up after doing all these possible causes, then I recommend looking at some maintenance records and finding an HVAC technician to take a look. Sometimes, all your AC may need is a good tune-up. Prevention is always better than the cure, and it’s important to remember that regular maintenance on your air conditioner is key to keeping everything in working order. So be sure to keep a close eye on it, especially before the hotter months set in.

Related Questions

What are the dangers of air conditioner freezing up?

If your air conditioner freezes up, it can cause water damage to your home. The water can leak out of the unit and onto the floor, and it can also damage the electrical components inside the air conditioner. Another thing, when your evaporator coil freezes solid, it can cause damage to your coils and other parts inside the condenser coil.

This will shorten the unit’s lifespan and reduce its energy efficiency rating, ultimately costing more in the long run than a simple tune-up would. As you might have noticed with yours, a freezing air conditioner might consume extra power to try and keep up. It might also take longer to cool the house.

About the author

Sharif Hasan

I am Sharif a data-driven marketer by profession and run The Spruce Air. I am very interested in keeping good-quality air inside of my home. Besides, I love to share my air-related knowledge through my website.

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