Why Is My Air Conditioner Freezing Up?

If your AC freezes, you will notice a buildup of frost on the copper that comes out of the system. Sometimes the frost build up can be so bad that a full block of ice forms. Luckily, solving the issue is often very simple. Just because your air handler is frozen doesn’t mean there is a serious problem with it.

What to Do When Your AC Unit Freezes Up

The first step to fixing your frozen AC is to turn the system off, if your AC system is still trying to cool, it will continue forming frost.

In severe cases, you may even want to turn your thermostat to the heat setting to speed up the thawing.

While your air conditioner is thawing, be sure to watch the water levels in the unit. If the drain pan inside the evaporator coil overflows, you can experience water damage in your air conditioner.

Why Is My Air Conditioner Freezing Up?

1. Low Refrigerant

Sometimes AC freeze ups can be because of the refrigerant chlorodifluoromethane, also known as R22.

R22 refrigerant has different physical properties at various levels of pressure. In a properly functioning system, the way the refrigerant is passed through the lines it is at a temperature where condensation may form on the outside of the line.

If something happens and the pressure in your system changes, the pressure change can cause the R22 to act differently. As the moist, warm air from your house moves over the evaporator, the moisture will condense and freeze on the coils and ice will begin to form!

You might not notice a change in the performance of your system with minor frost, but too much ice will affect the airflow.

Eventually, the ice will act as an insulator and prevent the air conditioning system from functioning properly, and the R22 refrigerant will evaporate faster. When the refrigerant level gets too low, your air conditioner can’t freeze the line. The ice may melt, and then you’ll notice the air flow behavior has stopped — but you’re not getting any cooling at all from the system.

If your system does not cool anymore, your AC potentially has water damage. We recommend having an HVAC professional inspect your home as soon as possible to repair it

2. Poor Airflow

If your AC can’t get enough air, then there won’t be enough heat (from the warm air in your home) to prevent the condensation on the coil from turning into ice.

Check and replace your air filters first. Even if your air filters are clean, poor airflow could still be the problem.

Inspect all of the air vents in your home, holding your hand in front of them to feel for air leaking from the sides of the grate.

You’ll want to also look for blocked ducts, closed or blocked grates, and closed dampers.

3. Dirty Coils

The third most common cause of AC freezes is a dirty air conditioner coil. Again, ice obstructs the proper airflow of your system — so what starts off as a little bit of frost can spiral out of control into a solid block of ice.

The reason your evaporator coils can freeze is that in addition to cooling the air inside your home, air conditioners also dehumidify it. They pull the water out of the air, which makes condensation that builds up on the coils.

Normally this isn’t a problem because the condensation droplets fall off the coils into the drip pan. But if the drip pan is overflowing, the coils can become waterlogged and freeze.

Dirty coils can cause freezing because the layer of dirt on top of the coils can prevent them from absorbing the water fast enough. Bi-annual checkups from your local HVAC professional can keep your AC’s coils clean.

4. Damaged Blower Fan

Your air conditioner’s blower fan helps get cold air where it needs to go and get the warm air outside.

As the air cools inside of your air conditioner, it becomes denser and doesn’t travel as well. The blower fan helps move cold air by “sucking” hot air out of your home, which the denser cold air moves to replace.

How effectively your AC can create cool air and push it out to you is 100% dependent on your machine having the correct balance of airflow and air pressure.

Sometimes your blower fan can break, or become damaged during normal operation. When your blower fan is on the fritz, that significantly changes the airflow inside of your air handler. Too much condensation will build up on the coils, and the water droplets will not evaporate or drain properly.

Without the hot air moving over the proper parts, a broken blower fan can also cause a refrigerant line to freeze too. If your refrigerant line is frozen, be careful! The freeze can easily back up all the way to your condenser unit outside, causing problems.

Air Conditioning Services in Orlando

If you catch it in the early enough stages, you may be able to handle an AC freezing issue yourself. But if the freeze up is the result of dirty coils, or your system has water damage you can call us or schedule an appointment online. Our team of experienced technicians provides quick, efficient repairs when your AC is frozen.