Air conditioners ice up when the cooling coil becomes colder than the dew point in the home. A window air conditioner can make a hot day much more bearable indoors. These units are designed to cool no more than one or two rooms, and they work best when the size of the unit fits the size of the room it's cooling. Ice can form on the unit and stop it from cooling if the air conditioner is too large for the room or requires cleaning. Deicing the unit properly to avoid damage takes time, but performing some general cleaning afterward can prevent the problem from happening again. Turn the unit off immediately if the fan is no longer spinning. Continuing to run a frozen air conditioner can damage the unit if the fan has also frozen. Allow the unit to thaw naturally until water begins dripping freely before attempting to turn the fan on again. Turn the air conditioner to the fan-only setting if the fan isn't frozen or after it has begun to thaw. The warm air circulating through the unit can help thaw the frozen coils.

Spread towels beneath the unit inside the home. As the air conditioner thaws, water will drain from the unit. Inspect the unit periodically for thawing. It can take an hour or longer for the unit to thaw depending on the extent of the freezing and whether the fan is able to run. Exchange the towels for dry ones if necessary. Turn off the air conditioner after it has thawed sufficiently for you to access the filter. Remove the front panel of the air conditioner to reveal the filter. Remove the filter from the unit. Clean the filter with warm water and laundry detergent to remove the dust and other debris that could be blocking it. Rinse with clear water. Allow the filter to air-dry completely before replacing it in the unit. Examine the exterior of the unit. Remove any debris blocking the condenser coil vents on the outside of the air conditioner. Debris inside the coils requires complete disassembly and cleaning of the unit, which is best done by trained service professionals. Turn the unit on after it has thawed completely and the vents and filter are clean.

Adjust the thermostat so the unit automatically shuts off when the room is at the desired temperature. Window units are less likely to ice over if they aren't left constantly running. how to hide window ac unitWhen the refrigerant inside a central air conditioning unit falls below 32 degrees Fahrenheit, humidity that surrounds the coils freezes. ac power supply frequencyThe coils become encased in ice and the air conditioning unit fails to cool the home properly. air conditioning units for data centerOnce you’ve thawed the coils, you have several options before calling a repair person to fix the unit. Just be sure to turn off the air conditioner first. Running the unit with the coils iced over can strain the compressor and cause it to fail.

Thawing Although you may be tempted to help the thawing effort by removing chunks of ice by hand, resist that temptation. The coils and cooling fins in the evaporator portion of the central air conditioner are easily damaged. Ice clings tightly to these components, and forcefully removing it can bend fins or rupture coolant lines. Instead, turn off the air conditioner but keep the blower running. This forces warmer air across the evaporator, which hastens the thawing process. Thawing may still take several hours. Quick Fixes Restricted airflow can cause air conditioners to work harder, which results in iced coils. Check the air filters first. If they are dirty or clogged, replace them with clean ones. Another cause of restricted airflow occurs when too many supply registers are closed. Check all the rooms in the house and ensure the registers are open. Clogged and dirty cooling fins in the frame that surrounds the coils might strain the system enough to cause icing. If outside air temperatures fall below 60 degrees Fahrenheit, most central air conditioners do not work properly.

Consider shutting the system off when temperatures fall below 60 degrees. Refrigerant A low refrigerant level is a common cause of iced air conditioner coils. Call a qualified service technician to check and refill refrigerant. Air conditioning repair people understand how to work with the pressurized refrigerant system and will be able to quickly determine which type of refrigerant your system needs. Air conditioning coolants can freeze skin tissue on contact, so personal safety is another consideration. Refrigerant loss is caused by leaky systems or it may occur over time in older units. A service professional can check for and repair leaks. Contactor After thawing the coils, the air conditioner may take a long time to cool the living space again. Once the space reaches the temperature you set on the thermostat, the central air unit should automatically shut down until temperatures rise enough to warrant the air conditioner to cycle again. If the unit fails to shut off when temperatures in the living area hit the thermostat setting, the cause might be a failed electrical contactor in the outside portion of the central air unit.

Like adding refrigerant, this is also a repair best left to trained air conditioning specialists. References HVAC Parts Outlet: Troubleshooting a Frozen Evaporator CoilHorizon Services: Help! My Air Conditioner is Frozen!Reliant Air Conditioning: Air Conditioning Troubleshooting: Frozen AC PipesWeathermaster: Help! Why Is My Air Conditioner Frozen? 20,317 posts, read 15,073,405 times 25,901 posts, read 21,074,479 times 3,750 posts, read 15,267,568 times When a central air conditioner freezes up, what actually freezes is the condensor unit's evaporator coil. This is the part of the air conditioning system that transfers (evaporates) heat from the inside to the outside of the home. There are two primary reasons the evaporator coil may freeze, it can either be due to 1) restricted air flow, or 2) lack of sufficient refrigerant. Either way, the result is that the air conditioner's evaporator coil cannot operate to properly dissipate heat, and in effect 'overcools' itself.

The result of this super-cooling is condensation (that's water formation), and eventually ice from that condensation as it cools below the freezing point. Yep, the A/C just turned into an old-school icebox. Basic Tips for AC Repair and Maintenance Originally Posted by Barking Spider Filter is brand new. he checked air flow and temp conversion etc. The unit is 12 years old and never used hard. I never have my temp below 76 in the summer. Input and out put lines also freeze so does the tank inside the unit out side. Its a carrier high eff. Originally Posted by AksarbeN What ever he did seems to have made it worse. 2,322 posts, read 2,396,739 times Originally Posted by tinman01 Well contact him to return and 1. either fix it properly or 2. you will have someone else do it and he will eat cost of the service if it is determined that his initial work, indeed made things worse. 222 posts, read 301,003 times inexpensive fiberglass filtershigh dollar thick filters restrict too much air flow