NOT COOL – Why Did My Air Conditioner Freeze Up?

Today we’re going to spend a little time on the reasons why it is so important to maintain your air conditioner and the things you need to do if you find that your AC system has turned into a giant ice cube.

Let’s start with the maintenance. As we all know, an air conditioner is a big investment and one of the biggest mistakes people make is not having the proper routine maintenance performed on the AC unit. For some unknown reason, people just don’t change the filters the way they should on a monthly basis. This leads us to the first reason an air conditioner can freeze. A very dirty filter reduces the air flow going across the coil, and without proper air flow the coil gets too cold, the house doesn’t cool correctly and you end up with a big block of ice.

The same holds true if the indoor coil itself is extremely dirty restricting the flow of air. Again, not changing the filter or lack of maintenance is the root cause of that indoor coil getting dirty. In addition, if the flow of air through the outdoor coil is restricted by foliage or if it’s extremely dirty, you may also find yourself in the frozen tundra.

The next big thing that causes your system to go into frozen mode is a refrigerant leak somewhere in the circuit. The refrigerant circuit is just a big loop that goes from the indoor coil to the outdoor unit. If a leak develops somewhere in that circuit, you will lose Freon causing the unit not to cool correctly and once again freeze. This is typical in older systems that haven’t had regular maintenance done.

The last tip to avoid freeze-ups is not to set your thermostat lower than about 68 degrees. Setting the thermostat lower than 68 degrees will again make our indoor coil get too cold, and the end result is the same as a dirty filter or lack of refrigerant. On a side note, if you choose us as the company to maintain or install your AC system we can install a freeze control in the air handler that if the coil goes below 33 degrees, it will shut the unit off to prevent a freeze-up.

If you find that your unit is not cooling and appears to be frozen, obviously call us, and then head to the thermostat! Turn the cool setting to off and the fan setting to on. This will stop the refrigerant cycling and the air flow going across the coil will help melt the ice. If we come out for service and it is a giant block of ice we will have to re-schedule the service call until the unit thaws out. We cannot diagnose or repair a unit that is in the frozen state. Once more just to drive the point home, changing your filters and proper annual maintenance of your air conditioner can help avoid the dreaded freeze up.

Until next time my friends, what if the hokey pokey is NOT what it’s all about?

House Whisperer out!