Why is My Air Conditioner Frozen?

Have you ever experienced this situation? It’s as hot as a desert outside but your AC isn’t working. You peek inside your air conditioner and it looks like a miniature diorama of the North Pole, with ice sticking to all of the surfaces. The only thing missing is tiny penguins sliding down the icy slopes. It doesn’t seem like something frozen could exist outside when temperatures are so hot. But it can happen to any air conditioner, even when it’s sweltering in Boise, ID. Our team at TSS Home comfort will take you through why this happens and what you can do about it. 

Why Do You Have a Frozen Air Conditioner?

No one can argue that a frozen air conditioner is much less fun than frozen yogurt. Instead of making you nice and cool on a summer day, it’s going to do the opposite. But to understand why you’ve got ice on your line or pipe outside, it helps to know a little of the basics of how your AC works. 

Airflow is crucial to the process. The hot air in your house is pulled across the evaporator coil which is filled to the brim with refrigerant. The heat in the air makes the refrigerant “evaporate” into a gas. From there, the air (which is now cold) is put back inside your house where you can enjoy it. But while you’re sitting in your comfortable home, the refrigerant is still making a journey. It moves outside to the compressor where it’s pressurized and heated up. Finally, it goes into the condenser unit where the heat is set free into the outside air. The liquid refrigerant goes back inside to start all over again. 

Remember we said that airflow was important? With so many tiny little parts that all need to be working together to make your AC work, it’s understandable that things will occasionally go wrong to limit airflow in the system, requiring air conditioner repair. That’s why it’s great to have someone like TSS Home Comfort in your contact list to call when things get dicey. Here are the most likely culprits of an AC unit freezing up in summer. 

Air Filters and Air Ducts

Air filters and air ducts might be first on your mind when you think of airflow. Warm air can’t reach the evaporator coils if it can’t even move through the ducts or the filter. The first thing you want to check when you have a frozen air conditioner is whether you have a dirty filter or blocked air ducts. Solve this problem, and the ice on your line outside will melt away. 

Blower Fan

Just as crucial to airflow is the blower fan. If the fan is jammed up and isn’t getting enough warm air past the coils, the ice can start to form on the unit! 

Drain Lines

Just like with the drain of your bathtub, your air conditioner’s drain line can get clogged by sludge and minerals too. Getting it clean can help keep leaking water in your window air conditioner from freezing up. The same can be said for the drain lines in your mini split or central air conditioning systems.  

Evaporator Coils

When an air conditioner doesn’t get regular maintenance, evaporator coils can get crusted with everything from dust to mineral buildup. Not only is that not pretty, but it’s also putting a barrier between the warm air and the refrigerant. 

Refrigerant Leaks

It might seem backward, but if you don’t have enough refrigerant flowing through your AC, it’s going to get colder inside your system. A leak will make your AC line freeze up in a hurry whether you have a window unit or a central AC.

Unfreezing Your Frozen Air Conditioner

Now that you know what causes it, you might be ready to find out how to unfreeze an air conditioner. Of course, you will always want to solve the root problem. An AC is just going to freeze again if you don’t fix the dirty air filter or the leaking refrigerant line. While you wait for your technician, however, you can start to get the ice off your system. 

You can pour hot water on a frozen air conditioner, but make sure to always unplug it first. Never pour water where there are electrical wires, and don’t pour water where it can pool in your house and cause damage. You should not try to use a hairdryer or any other hot device to melt off the ice. If you have time, it is better to defrost it without hot water by turning your thermostat’s settings from “cool” to “fan” and letting it run for a few hours. 

How long it takes to thaw a frozen air conditioner can depend on how big your AC is, how much ice has built up, and how hot it is outside. Expect it to take somewhere between 1 and 24 hours. 

Don’t let a little ice on your AC ruin your day. Most likely it will be an easy problem to fix and your air conditioner will be running again in no time. But if changing the filter doesn’t do the trick, you’ve always got your friends at TSS Home Comfort to help with any AC repairs. So whether your AC unit is frozen, too loud, or leaking water, give us a call.