It’s a bizarre, yet common sight. There you are in the middle of summer. The sun is beating down. Everyone is wearing shorts. And your outside air conditioner unit or heat pump is caked in solid ice. How is it possible for an air conditioner to look like an igloo, even in the warmest summer months? Needless to say, it is abnormal for ice to form on an air conditioner, and it is certainly cause for concern. Several common problems can cause air conditioner freeze-ups: The buildup of ice and frost is a sure sign that your air conditioner is not operating properly. If you notice a decline in your system’s cooling capacity, ice build-up should be the first thing you suspect. Air conditioner freeze-ups should be addressed immediately; continued ice accmulation can cause permanent damage to your a/c unit. The first thing you should do once you notice your air conditioner is frozen is to turn it off and let it defrost completely. Once it has defrosted, check the airflow. Clean or replace dirty filters or remove any visible dirt or obstructions;

in some cases, this could be all that is needed. More serious airflow and refrigeration problems require professional intervention. Schedule a Service Call with Horizon Services; your Horizon service technician has all the tools necessary to troubleshoot serious air flow problems and repair refrigerant leaks. If your icing problem is due to drops in the outdoor air temperature, be sure to turn your air conditioner off when the mercury takes a drop. You should also consider installing a special ambient temperature control that will allow the unit to run properly in cooler temperatures. While all HVAC equipment should be checked by a professional once a year, and an HVAC professional should always be called in to deal with major issues or repairs, you can extend the life of your HVAC system by performing an annual precison tune-up. And, if you are ready to install or replace your air conditioner or heater our friendly and experienced team of Comfort Specialists know air conditioning and heating systems inside and out.

They’ll take the time to study your home, understand your cooling and heating requirements, show you all of your options and assist you with finding the quality home comfort system that best meets your family’s needs and budget.why are ac units on the roof For Fast, Friendly Service – 24 Hours a Day/7 Days a Week:how much copper in an ac unit Horizon Services: The only full-service plumbing, heating, air conditioning, geothermal, drain cleaning and sewer and water line replacement company in Delaware, Southeastern Pennsylvania and Maryland that guarantees on-time service, up-front pricing and the job done right and clean the first time!how many amps does a ac unit use If your air conditioner seems to be losing its cooling ability, the problem may be as simple as frozen or clogged air conditioning coils.

Other causes of reduced cooling include restricted air flow and low refrigerant. Even though you may not be experienced in AC service, you can fix all three of these probable causes in several easy steps. Step 1 - Thaw Frozen Condenser Coils Find your electrical breaker box and turn off the switch that controls power to your air conditioner, and allow the coils to thaw. Depending on the ambient air temperature around your condenser unit, it could take up to 24 hours for the coils to melt any ice that is plugging them. Step 2 - Dry the Air Conditioner Coils Once your condenser has had time to thaw completely, remove any pooled or standing water and use a towel to dry any remaining moisture that may remain on the machinery. Step 3 - Turn the Air Conditioner's Fan On After turning the breaker switch on again to restore electricity to your AC, find the thermostat that controls your unit. Set the thermostat control so that only the air conditioner's blower, or fan, is operating.

The fan will help melt any ice or frost clogging the coils by circulating air through them. Step 4 - Heat the Condenser's Coils You can speed up the thawing process by using a hand-held hair dryer. Be sure when you use this method of heating that you switch the dryer setting to low heat. A heat setting that is too high can crack the condenser's coils. Step 5 - Check Vent Filters Vent filters, when clogged with dirt and dust, are likely to reduce air flow and conditioner's ability to cool your house. To maximize cooling efficiency, you will need to check your vent filters. If they are dirty or clogged, replace them with new ones. If you don't have extra filters on hand, you'll find them at most hardware or home improvement stores. Step 6 - Add Coolant Another condition that often reduces cooling efficiency is low coolant in your AC unit. The best way to check for low coolant, and add it when necessary, is to buy a coolant installation kit which you can usually find at a nearby home improvement store.

Most of these kits will include directions for adding the coolant. Step 7 - Test the Cooling Capacity Once you have completed the rest of these steps, test your air conditioner's ability to cool. Turn the thermostat setting to "cool," wait a few minutes, and then test the air coming from the vents. If the air blowing through the vent is as cool as you would like it to be, you can rest assured your repairs were successful. How to Clean Air Conditioner Coils I noticed my house wasn't getting under 75°F this weekend when I had the thermostat set for 70°F. Since I'd done a lot of drywall sanding inside recently, my first idea was to replace the filthy air filter. My first indication that the air filter wasn't the root cause was when the return didn't have enough suction to hold the air filter in place while I was replacing it. I went outside to look at the compressor unit and discovered the exposed portion of the refrigerant line running into the house was frozen, but the fan was still running.

The evaporator drain line still had a steady stream of water coming out of it. After turning everything off and waiting for the line to thaw, I turned the thermostat back on. Cooler air came out of the vents, but it didn't seem to be blowing with much force, and it wasn't as cool as it should be. I went back outside and discovered the refrigerant line was already frosting up again. At this point it was already dark, so I turned everything back off and slept with the ceiling fan on. Other random notes that may or may not play a factor: The AC unit had been sitting idle the past 3 days since we had nice weather in the mid-70's last week. I mowed the lawn next to the condenser unit the day I noticed it stopped working. However, I was bagging the grass clippings, so nothing should have been blown into the unit. Any ideas on the root cause of the icing and lower air flow? I wouldn't think the two would be connected normally. Is it something as simple as low refrigerant levels?

I plan on going to look more closely at it after work today. What are some other things I should pay attention to? UPDATE: I checked the system after work today and decided to give it one more chance after I couldn't find anything wrong with it. After a few hours, it had brought the inside temperature down from 80°F to 75°F. I periodically checked the refrigerant line for freezing, but it never got much colder than 60ish degrees. I think the root cause was the air filter, and that I didn't allow enough time for the line to thaw last night. UPDATE 2: Maybe I drew conclusions too soon - I just checked the refrigerant line and discovered frost on it again. The inside temperature was at 72°F while the outside was at 66°F. I think pumping warm air to a cooler outside temperature may have contributed to the icing, but I'm not completely sure. (And if you think I'm crazy for running the AC when I could just open the window, you'd think twice too if you saw how many bugs swarm my porch light and windows every night.

Dozens of them somehow find their way past the screens if I open the windows.) I plan on running it again tomorrow during the day and monitoring the refrigerant line temperature every few hours. If it freezes up again, I think I'm going to cave and call a repair guy. UPDATE 3: I totally forgot to follow up on this. It froze again, so I called an HVAC repair guy. He checked the system, added refrigerant, and problem solved. I think the bill came out somewhere around $150 for the service call fee and refrigerant costs. You may be looking at the problem backwards, the freezing lines could be a symptom of the problem not the cause. Start by looking for blockages in the system that would cause lower air flow / heat exchange. Basically if the system cannot exchange the heat/cold, it will not function properly and could lead to over heating/cooling. Frozen lines could also be caused by high or low levels of refrigerant, so you'll want to get a service person out to check the refrigerant levels.

Here is a really good image to visualize how it works. My A/C's frozen up before due to insufficient airflow over the evaporator coil. Turns out those $20 allergen-blocking air filters can slow down the air too much, so I switched to a cheaper one that doesn't block the air flow as much. My A/C guy also told me that running the A/C when it's cooler outside than inside can cause it to freeze up in certain conditions like low airflow or low freon. My guess is a dirty "A" coil or blower wheel. There also may be a leak in the system. If it is the coil or blower wheel, clean it and there won't be a problem any more. If there's a leak adding freon will only temporarily fix the problem. The system should be leak free and refrigerant shouldn't need to be added. If the small pipe is frozen, the gas is insufficient. Call a service man to recharge some gas again. protected by Niall C.Browse other questions tagged hvac air-conditioning central-air or ask your own question.