What To Do If Your AC Freezes Up

It may seem abnormal for an air conditioner to freeze up and have layers of ice covering the unit, but this is actually a common occurrence. Luckily, this is not the end of the world, or the end of the unit for that matter.  If your air conditioner freezes over there are a few procedures you can follow to thaw it out and get it working again.  There are several reasons for this to occur. Pay attention to what may cause your unit to freeze so you can prevent it from happening in the future.

Possible Causes:

One cause for an air conditioner to freeze over is having insufficient air flow.  If your filter is clogged, this can be the cause of your problem.  Make sure you have a clean filter and also make sure nothing is lodged in the intake of your system.  When the air flow is restricted this will cause the other equipment to overwork itself and trick your system into pumping cold air to the point where it freezes over.  Air conditioners have a part called the evaporator coil.  When this coil drops below freezing, the humidity in the air will collect itself on the coil and eventually ice will build up.  Your air conditioner needs a clear path for air to flow through the system for proper operation.

Air Conditioners also have refrigerant, if this liquid gets to a low level or is leaking out of its container it will also affect the evaporator coil and cause moisture to collect on the coil, eventually freezing it over.  Look for any draining liquid or puddles around your system to ensure there is no liquid leaking from the system.

Extreme temperatures can also be a cause for it to freeze over.  When the ambient temperature is above 100 degrees F, the system will be overworked and cause its inside parts to freeze up.  Temperatures below 60 degrees F will also have adverse effects on your system, and at that temperature you should not be running your AC in the first place.  Make sure to monitor the temperature setting, and make it appropriate for the surrounding temperatures in your home and outdoors.

Repair Solutions:

If you notice ice build up on your system, you need to do maintenance immediately to prevent permanent damage to the unit. The first and only thing you should do is turn off your system. Keep the AC off until all of the ice naturally thaws out and melts completely off of the unit. Ice build up on the system can block air flow and ruin the system. Air conditioners ultimately rely on air flow through the system to function properly. After the ice has melted, make sure there is a clear passage where the air filter is placed and also in the ducting of your system.

There is a piece of equipment that can be installed on AC systems to help control how it works in cooler temperatures. This is an ambient temperature control sensor that will adjust the settings to work properly in cold weather. This way if you are away from your home and cannot change it yourself, the sensor will take care of your problem. Since many of us work during the day and sleep at night, a control sensor would be highly advisable as we cannot monitor our air conditioner day and night.


If the air conditioner still isn’t functioning correctly after thawing out the system and checking the ducting, then consider getting professional help. It may be a part of the system that you cannot diagnose or see which will require professional help to find out what part(s) may be damaged and need replacing. Consider this as your last option as it may be expensive if you cannot fix the problem on your own.

Nick Quinlan is an Orlando resident and a bit of an enthusiast for do-it-yourself home projects. Though he tries to maintain what he can, he knows he can’t fix everything, and for those AC problems he can’t resolve he turns to Facemyer Air Conditioning & Heating. You can learn more about Nick by visiting on Google+.