The last thing you expect to see on the outside part of your air conditioner is frost. Frost and ice can develop even on a hot summer day when your AC is malfunctioning. There are a few causes of this odd problem, and here's a look at two of the causes and the repairs you might need to have done.
Your air conditioner needs the right amount of air flowing through it and around it to work right. This is important for allowing the refrigerant to cool your house. If the airflow is blocked, the refrigerant coils can get too cold and cause frost to form.
The first step is to turn off your air conditioner so the ice can thaw out. While the ice is melting, look around for blocked vents, a clogged and dirty filter, and a blocked condenser. If you see anything blocking airflow, clear the obstruction. Also, change the filter to see if that helps. If you can restore the usual amount of airflow, your AC might start working properly once the ice has melted and you turn the unit back on.
If your AC still malfunctions, there could be another reason for reduced airflow that an AC repair technician needs to track down, such as a blocked duct, bad blower, bad blower motor, dirty air handler, or dirty condenser.
Another common cause of frost and ice on an air conditioner is low refrigerant. A refrigerant leak is a little more complicated because you may not be able to tell if the refrigerant is leaking, and if it is, the AC repair technician has to track down the source of the leak to fix it.
You might hear a hissing noise when the refrigerant is leaking, but you may not have any signs other than an iced-over AC. The repair technician can measure the pressure in the lines and tell if the refrigerant is low. If so, the next step is to look for the leak, which could be anywhere along the condenser coils, evaporator coils, and the copper lines that connect them.
Once the leak is found, the technician can repair it and then fill the refrigerant. With the refrigerant at the proper level, your AC should cool your house normally again as long as the coils are clean too. If the coils are dirty, the technician will probably clean them so your AC can work optimally.
A frosty AC is an inconvenient problem since your AC may shut down, and you'll need to turn the AC off anyway to allow the ice to thaw. You can avoid this problem sometimes by having your AC cleaned in the spring and by changing the filter regularly.
However, you might not be able to prevent a refrigerant leak, and a leak allows the refrigerant to get lower and lower until your AC can't cool at all. That's why it's important to call an AC repair service for help when your air conditioner gets frosty.