Why Are My A/C Coils Frozen?

Wondering Why Your AC Coils are Frozen? 

AC coils can freeze any time of year—and that can be a major problem for your home’s heating and cooling system. Whether winter is fast approaching or we are in the middle of summer, it’s always a good time to check in on your AC. By spotting issues early—and by integrating preventative maintenance into your annual routine—you’ll keep your AC coils in good, working order, while ensuring your indoor spaces are always cool and comfortable. 

What Causes an A/C Coil to Freeze?

AC coils freeze for a variety of reasons—the most common, though, is lack of airflow. Dirty air filters or problems with your ductwork can cause weak airflow, which hinders your equipment and its ability to keep coils warm and running properly. Temperatures drop and the AC coils freeze.

Refrigerant leaks and a wide variety of mechanical issues can also result in frozen coils. The cooling process, for example, creates condensation that can pool on the coils and freeze if it isn’t drained properly. The ice insulates the coil and interrupts the heat transfer process.

Signs of a Frozen A/C Coil 

Regardless of how AC coils freeze, the end result is usually the same: your AC system can’t effectively cool your home. Plus, you’ll probably run up your utility bill desperately trying to achieve a comfortable indoor climate.

Unsure if you have a frozen coil? Here are some signs to watch for

• AC unit runs but doesn’t emit cold air
• Ice is visible on the indoor or outdoor coils
• Visible extra moisture/condensation around your AC system or home 

Troubleshooting Frozen AC Coils

 If you suspect you have a frozen coil, start with a few simple troubleshooting techniques: 

1. Ensure the air filter is new and clean. Clogged air filters restrict airflow, causing the equipment cool and freeze.
   
2. Turn off the thermostat setting and turn the fan on. This process pushes air over the indoor air coil, potentially unfreezing it. Check back in several hours.
   
3. If your heating and cooling system has a heat pump, turn on defrost mode. Your AC unit may also have instructions for de-icing.

How Do I Fix a Frozen AC Coil?

If you’ve followed these DIY steps above and still aren’t feeling any cool, it’s time to call Choate’s HVAC. During your free inspection, we’ll assess your system and make a recommendation for repairs. Whether it’s a quick professional coil cleaning to remove dirt and grime, correcting refrigerant leaks, repairing ductwork or eliminating clogs in the drain pan and lines, we’ll get to the bottom of your coil freezing fast, and get your space cool and comfortable. 

If your AC unit isn’t emitting cool air or your system is due for annual maintenance, get in touch today to schedule a consultation. If you haven’t turned on your AC system in a while, it’s a good idea to start it up and test it before the summer heat hits.