When enough ice accumulates on your air conditioner's coils, it will often stop working until you give it a chance to thaw out again. This problem can be frustrating when it happens time and time again. If you're tired of sitting there in the heat, waiting for your air conditioner to thaw, then it is time to figure out why it keeps freezing – and make some changes to keep it from happening again.
Are the coils dirty?
One common cause of freezing is dirt buildup on the coils. When the coils are dirty, they hold onto moisture instead of allowing it to drain away. Also, the air is not as effective at "taking up" the coolness from the coils, since the dust acts as a sort of insulating barrier between the air and the cold coils. This combination can lead to freezing. If you spot any dust or dirt buildup on the coils, turn the power off to your unit, and rinse them off with the garden hose. Then, change the air filter so the coils don't get that dirty again. (Dirty coils are almost always caused by forgetting to change the filter.)
Is there insufficient air flow across the coils?
Air is supposed to travel across the coils, cooling off as it goes. If the air flow is impeded, then the coils may get too cool and freeze. Often, a lack of air flow across the coils is caused by closed or blocked vents. Go around the house and make sure all of your vents are open. Also, make sure there is nothing in front of the vents that may be blocking them. When the air conditioning is on, walk in front of each vent to make sure air is actually blowing out. If the air flow through one or more vents seems slow, have your HVAC technician out to check for a blockage.
Is the drainage hose blocked?
If the drainage hose becomes blocked, moisture won't drain away from the coils properly. Instead, it will accumulate and freeze. Locate your drainage hose. Typically, it is thin, clear hose that leads either to a drain or a pump. When the air conditioner is running, make sure you can see water moving through it. If no water is moving through it, or if you can physically see a blockage, try to press on the hose and push the blockage through with your fingers. If you cannot work it loose on your own, your HVAC technician can unclog it (or perhaps even replace it – they're inexpensive).
For a local HVAC contractor, contact a company such as Long Beach Heating & Air Conditioning Inc.