What to do when air conditioner freezes up? (2024)

What to do when air conditioner freezes up?

Turn the Thermostat Fan Setting to On. Turn your thermostat fan setting to “On” so that the fan continues to blow air over the coil. The warm air in the home will naturally defrost the frozen coil. In severe cases, the heat can be turned on to speed up the process.

What to do when your AC unit freezes up?

The first thing you need to do is turn off the air conditioner and let it defrost. After it's had sufficient time to thaw (1-3 hours), turn on just the fan for about an hour. Use this time to change your air filter. You can check out our article on how and when to change your AC filters.

What is the main reason AC freezes up?

The leading cause of a frozen HVAC system is a dirty air filter. The air filter cleans the air circulated into your home. As your AC system runs throughout the summer, the filter catches dirt, pollen, dust, and other allergens. This can restrict airflow and could lead the HVAC coils to freeze.

How do I unfreeze my air conditioner fast?

If the AC unit is blowing hot air, first try turning off your air conditioner but leaving the fan on so it can defrost the AC unit. The AC's indoor fan will blow warm air over your AC's frozen coils, helping the ice thaw faster. Also check for a dirty air filter, which could be causing air flow blockage.

How long should I leave my AC off when frozen?

To thaw the ice out, first, you need to turn the AC's thermostat off and turn the fan on. Leave the fan on for a few hours to allow the unit to fully defrost. In some cases, it may thaw out after an hour. In other, more extreme cases, you may need to leave the fan on for a full 24 hours.

Can I fix frozen AC myself?

You can also simply, turn off the system and turn on the blower to help thaw the evaporator coils. It's best not to try to clear the ice by hand which could also damage components. Once the condenser and coils have thawed, remove any standing water that may have pooled around the equipment.

How long can an AC run before it freezes up?

The only likely problem is the evaporator coil inside your furnace/air handler could ice up. This sometimes happens when humidity is high and the unit runs continuously for many hours, as the evaporator coil has no opportunity to defrost. And it's most likely to happen during the first 6 hours or so of unit operation.

Can an overworked AC freeze up?

Unfortunately, it's possible for your air conditioner to become overworked, and actually restrict the airflow to your home. As toasty as it may be outside, your air conditioner can actually become frozen.

Can low Freon cause AC to freeze?

Another thing that causes an air conditioner to freeze is low refrigerant or Freon. This causes a drop in pressure inside the evaporator coil, which then allows moisture in the air to accumulate and freeze on the coil. A leak is typically responsible for low refrigerant.

How long does it take for AC coils to unfreeze?

The coils might take up to 24 hours to completely thaw if left to their own devices. Here's what you should do to keep the air conditioner from freezing: Make sure the refrigerant level is correct. Replace the filter every month.

How do I know if my AC coil is frozen?

Should I turn my AC off if it's frozen?

1st Step: Turn Your HVAC Unit Off.

Even if it's sweltering outside, you still need to turn OFF your air conditioner! Running a frozen air conditioner will wear out parts much faster, and could overheat your unit. Worn parts are bad news for the most expensive piece of your HVAC unit—the compressor.

At what temperature does an AC unit freeze up?

This can be a problem during the springtime when temperature levels can rise and fall unpredictably. If your air conditioner is operating when the temperature outside is below 60 degrees, your coils have a chance of freezing over.

Can a frozen AC cause damage?

A frozen air conditioner will not cool your home.

If you let the problem persist, it can also damage your entire system. Ice, as you probably know, expands. And when it collects on your HVAC components, it can expand enough to break them.

Is it common for AC to freeze up in summer?

The simplest explanation as to why air conditioners freeze over during the summer months is simply that you use your air conditioner more when it's hot outside. The hotter it is, the more your system will run, and thus the chances of your system freezing increase.

What is dirty sock syndrome?

What Causes Dirty Sock Syndrome? “Dirty Sock Syndrome” refers to when a foul-smelling, mold- or mildew-like odor comes from your air conditioner when you first turn it on. This happens when moisture, dust, and dirt build up on your AC system's evaporator coil, inviting bacteria and mold to multiply.

What are the signs of low Freon in AC?

Can a dirty filter cause AC to freeze?

The most common cause of AC unit freezing is having a dirty air filter or blocked vent. Air filters can accumulate dust from the environment that are then blown into the system, while allergen-filled pet dander, lint and other particles can line vents if not cleaned and vacuumed regularly.

Can I run my AC with frozen coils?

1st Step: Turn Your HVAC Unit Off.

Even if it's sweltering outside, you still need to turn OFF your air conditioner! Running a frozen air conditioner will wear out parts much faster, and could overheat your unit. Worn parts are bad news for the most expensive piece of your HVAC unit—the compressor.

How much does it cost to fix frozen AC?

How much does it cost to fix frozen AC coils?

Average Evaporator Coil Replacement Cost

Replacing the evaporator coil on a central air conditioner costs $600–$2,000. The coil itself costs $180–$1,600, and professional installation adds another $400–$1,000. Here are the major factors that determine the total cost of the project.

Why is my AC running but not cooling?

If your air conditioner is running, but not lowering temperatures inside, one issue could be a blocked or clogged condenser coil. When operating correctly, the condenser fan draws air into the outdoor unit through the condenser coil to pull heat energy out of your home.

How do you get ice out of an air conditioner?

If you notice ice buildup on your air conditioner, the very first thing you should do is turn your air conditioner off and, if possible, turn the fan on. For relatively light ice buildup, this should help unthaw your air conditioner within an hour or two.

Is my AC broken if it freezes?

If your AC unit froze, it means your air conditioner has fallen below 32*F and ice has accumulated somewhere on the unit. This is a pretty obvious sign that there has been some malfunction and your air conditioner will need repair or replacement.

Why is my AC not working after a freeze?

As we mentioned previously, blocked airflow is the most common cause of your air conditioner freezing. After your air conditioner has completely defrosted, check the air filters. If they are covered in dirt, dust, and other debris, you need to change your filter.