What to Do About an AC Unit Freezing up in Summer

Your air conditioner is supposed to be cold, of course. But ice on your AC unit? That’s definitely not supposed to happen. Because Houston is warm enough to run your AC year-round, you can experience icing during any part of the cooling season. Still, your unit is the most likely to ice over in the summertime, while it’s working its hardest. In the less-demanding spring and fall, technicians are likely to catch problems during regular maintenance before they cause ice.

If you notice ice or frost on your air conditioner—likely on the evaporator coil—it indicates a problem that needs fixing. Before you call for professional help, here’s what you need to know when you spot frost during the cooling season.

Where to Look for Ice Buildup on an AC Unit

Ice usually forms on the evaporator coil in your interior unit. However, other parts of your system can be affected if a refrigerant leak pours ice-cold fluid onto part of your AC below the evaporator coils.

You may notice ice buildup if you go to check why your air conditioner isn’t functioning as well as it used to. Ice may be visible through the grate that covers your unit and may even push through that grate with extensive buildup.

What Causes AC to Freeze up in Summer?

Your Houston-area air conditioner may have frost or ice on it for a few different reasons.

Blocked Airflow

The simplest cause is that your HVAC’s airflow is blocked. A hot and humid Houston summer can cause your air filter to get dirty faster than usual. Multiple closed air registers inside your home can also cause AC icing by preventing proper airflow through your evaporator coil. If you’re too cold with all the vents open, consider raising your thermostat settings a few degrees.

Dirty Air Conditioner Coils

If you notice ice inside your unit, your air conditioner’s coils may be dirty. Dirty coils don’t work efficiently and may not allow the refrigerant inside to absorb as much heat from the air in your home as it should. Dirt and grime can prevent this transfer of heat, causing the refrigerant to sit at below-freezing temperatures, collecting frost. Coils can be delicate, so leave their cleaning to the pros during your twice-annual air conditioner tune-ups or schedule AC repair to clear up an urgent issue.

Blocked Water Flow

Your AC also produces water as it runs: from the exterior unit in a central cooling system or into a drain pan in a window air conditioner. If that gets blocked, backed-up water can flow into the unit, leading to ice on the evaporator coil. Call the professionals for air conditioner maintenance to address potential causes.

Leaking Refrigerant

The most dangerous problem comes from leaking refrigerant. If you notice a sweet chemical scent along with signs of ice, turn off your system immediately and schedule emergency HVAC service. Freon and other refrigerants are toxic and must be cleaned and dealt with professionally. If you can’t pinpoint exactly why your system is iced over, assume it’s a refrigerant leak and call for professional help.

How to Get Rid of Ice on an AC Unit

Ice can damage your air conditioner the longer it’s left unchecked, to the point of breaking your AC completely. Running your AC with ice or frost can even be dangerous, especially if a refrigerant leak is causing the ice. Iced-over ACs are also inefficient. If you can correct the problem immediately (such as a clogged filter), you can run your air conditioner with some light frost on it, but if the problem persists or you see ice crystals, you should always thaw your unit and contact the experts for repairs.

To get rid of ice on your air conditioner, turn it off for 24 hours to allow the ice to melt naturally off your unit.

If you suspect you might have a refrigerant leak, don’t turn your system back on before a professional can inspect it. If it’s just an airflow issue, change your filter and open all the vents in your home before flipping the AC back on.

How to Prevent Ice Formation in AC Units

Regular AC maintenance is the best way to prevent frozen coils. Make changing your air filter at least once every three months a regular part of your home care routine. And schedule routine professional maintenance. As part of our Comfort Club, you can enjoy annual tune-ups that include inspecting your entire HVAC system, cleaning your AC coils, and checking for refrigerant leaks.

Houston-Area Professional Repairs for an AC Unit Freezing up in Summer

Ice is nice, but it doesn’t belong on your hard-working Houston air conditioner. Schedule professional service with One Hour Air Conditioning & Heating of Houston to treat the cause of an iced-over air conditioner and prevent future problems. Call us now at (713) 352-7903 or book online.