Evaporator coils use a fan to push the hot air from your home over the refrigerant running through them. As the hot air, heats the refrigerant, they vaporize and absorb heat from their surroundings. If something happens to diminish the flow of air running through the coils, they can get too cold and ice over. When this happens, you don't necessarily have to call a repair technician. With a little guidance, you should be able to correct the problem on your own.
Removing the Ice
Your first step should be to remove the ice coating your coils. The first thing to do is to turn off your AC unit, or the refrigerant will continue to replenish its ice coating. Once you turn off your AC unit, the temperature in your home will start to climb, which might tempt you to speed up the melting process. Rather than start hacking at your evaporator coils in an effort to chip ice away, which may puncture the coils and create an even bigger problem, you should limit your efforts to using a hairdryer to speed up the melting process. Your biggest concern should be placing towels and/or buckets to catch meltwater before it makes a big mess.
Treating the Problem
Once your coils are free of ice, your work is not done. Remember that properly functioning coils do not ice over, so your next step should be to find what is causing ice to form. You should first check your filter. A severely clogged filter can decrease the flow of air, and without sufficient air available to warm the coils, they can get too cold. If your filter checks out, look to your fan. If your evaporator fan is not working, then you will obviously not have sufficient airflow. You will need to call a technician to make repairs to the fan. If your fan is working, then you likely have a leak somewhere in your refrigerant line. Federal law requires that you call a properly trained technician to make repairs to the potentially hazardous refrigerant running through your system.
You might think that if ice is forming on your evaporator coils, it is running a little too well. Because the ice can cut off the flow of air into your home, it will prevent your system from running up to is full potential. More importantly, ice on your coils is a symptom of a larger problem. Thus, when you discover ice on your AC coils, you should take steps immediately to correct the problem. At the least, you should be able to remove ice from your coils, before a technician shows up. This will help to ensure that you get a quick and therefore less expensive repair. Contact a professional, such as one from Dale's Heating & Appliance, for further assistance.