Here’s a problem you likely never thought you would experience: Ice on your HVAC in the middle of the summer heat. Don’t worry though, it’s actually much more common than you think! Very cold refrigerant coils + moisture in the air = ice.

As a homeowner, having a comfortable, temperature-controlled home is crucial for your overall well-being, especially during the scorching summer months. That’s why a frozen air conditioner is more than just an inconvenience—it’s a serious problem that needs swift attention.

When you’re running your AC unit more often and at colder temperatures, like you do in the middle of summer, they’re more likely to freeze up. If you notice something wrong with your AC, especially visible ice, it’s time to take action. We’re here to help you get the problem solved.

A “frozen air conditioner” may sound like an oxymoron, but it’s a common problem that can occur due to various issues. When we say an air conditioner is “frozen,” we mean that ice has formed on the evaporator coil, a critical component that absorbs heat from the air in your home.

When functioning correctly, the coil gets cold but does not freeze. However, when airflow is reduced or the refrigerant levels are too low, the coil can get too cold, causing the moisture in the surrounding air to freeze onto the coil.

How will I know if my AC is frozen?

Other than visible ice on any part of your HVAC unit, the next most obvious sign of a frozen AC unit is a lack of cool air. If you put your hand in front of your supply vents and you sense warm air coming out, you probably have ice somewhere in the system. 

You may also notice a hissing sound coming from the unit. If that’s the case, take steps immediately to prevent further damage. Your wallet will thank you later.

How to Defrost a Frozen AC Unit

Your air conditioner might take anywhere from an hour to more than a day to completely defrost. It’s important to catch it early to prevent further damage to your unit—and, of course, so you’re without cool air for the shortest amount of time possible. 

Here’s your step-by-step defrosting guide.

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. To avoid lasting damage and a hefty bill, turn your air conditioner thermostat located inside from COOL to OFF. This will start the defrosting process. 

2nd Step: Switch Your Thermostat Fan to ON.

• Turning the HVAC fan to ON will force it to blow warm air over any frozen coils—which will speed up the defrost process. Make sure it’s actually set to ON and not to AUTO. Automatic settings cause the fan to cycle—starting and stopping over and over again. You want continuous, non-stop airflow over the frozen areas. There is an option on your indoor thermostat to do this.

3rd Step: Locate the Source of the Problem.

Now it’s time for some investigative work. What caused your air conditioner to freeze up in the first place? There are a few common culprits:

Dirty Air Filter

• Clogged-up air filters will essentially suffocate your air conditioner unit. When warm air is restricted from the coils in your unit, the coils get too cold and eventually ice over. Replace air filters at least once a month to prevent an icy surprise.

Dirty Evaporator Coils

• If your coils are pretty dirty, the same process always occurs. Dirt, dust debris and grime covering the evaporator coils causes massive air restriction the same way dust will in your air filter.

Leaking Refrigerant

• If you spot a refrigerant leak anywhere, that’s probably going to be the main cause of your ice problem. Low refrigerant levels cause drops in pressure, allowing moisture in the air to freeze around your HVAC coils. 
• Despite what many homeowners may think, refrigerant doesn’t simply get “used up.” It doesn’t decrease over time, and it doesn’t evaporate during AC use. So if you’re low on refrigerant, there’s absolutely no doubt you have a leak. 
• Note: Refrigerant is an extremely hazardous chemical that should only be handled by licensed HVAC technicians. Give us a call if you think you have a leak.

Problem Parts and Other Issues

• A collapsed duct, weak blower, or closed valves might be causing your air conditioner to freeze. Air conditioner units are very complex machines with a lot of other pieces and parts. Our Northwest Arkansas, Fort Smith River Valley & Southwest Missouri HVAC pros can help to diagnose these less obvious problems.

4th Step: Keep a Close Eye on Your Air Conditioner.

• As your air conditioner unit thaws completely out, you might run into some additional damage. Drain pans that have overflowed and clogged condensation drains are a large risk when this much water is coming off your air conditioner. Place some towels around the unit and watch for any  additional leaks to prevent water damage. 

Once your air conditioner unit is completely clear of all ice and all parts are dry, you can turn your A/C back on. Keep a close eye on the unit for any continued problems over the next several hours to a few days.

Preventive Measures to Avoid a Frozen Air Conditioner

Prevention is always better than cure. Here are some preventive measures you can take to avoid dealing with a frozen air conditioner:

Regularly Replace or Clean Your Air Filter

• Keeping your air filter clean is one of the most critical steps in preventing your AC unit from freezing. Replace or clean it regularly according to the manufacturer’s instructions.

Schedule Routine Maintenance

• Scheduling routine maintenance can help detect any potential issues before they become significant problems. A professional technician can check your system for any malfunctioning components and ensure it’s operating at peak efficiency.

Ensure Proper Installation

• Improper installation of your AC unit can lead to various problems, including a freeze up. Make sure a professional installs your unit to prevent such issues.

Can I Pour Hot Water On Frozen Air Conditioner?

One question we are often asked is: , “Can I pour hot water on frozen air conditioner”? The answer is “Yes”. Pouring hot water will melt the ice faster and in turn, thaw your AC faster. In fact, the water does not need to be extremely hot, even warm water or running water will work to thaw the ice.

5th Step: Call us at Paschal Air, Plumbing, & Electric!

• If changing the air filter solved your ice problem, you’re in luck! Now it’s time to keep your unit in top shape throughout the summer. Getting regular preventative maintenance and inspections can help catch issues early and prevent your air conditioner (and your wallet) from freezing up.

Unfortunately however, replacing the air filter is the only thing you can do yourself. So if that didn’t work, it’s time to call the professionals at Paschal.

Frequently Asked Questions

How often should I replace my air filter?

• Typically, you should replace your air filter every 60-90 days. However, if you have pets or allergies, you may need to replace it more frequently.

Can I fix a frozen air conditioner myself?

• While you can take some steps to address a frozen air conditioner, like cleaning or replacing the air filter and ensuring the vents and ducts are unobstructed, you should call a professional if these actions do not resolve the issue.

Is a frozen air conditioner dangerous?

• While a frozen air conditioner is not directly dangerous, it can lead to other issues like water damage due to the melting ice. Additionally, the added strain on your AC unit can cause parts to wear out faster, which could potentially lead to more significant issues.