May 15, 2021
Frozen Air Conditioner in Drexel Hill, PA

The warm and muggy summer weather in Drexel Hill, PA, will have you turning to your air conditioner for relief. Air conditioners use a chemical refrigerant to transfer heat out of your home. The refrigerant cycles through the air conditioner’s outdoor unit and indoor unit. When the refrigerant enters your home, it’s very cold. However, it’s not frozen. If you notice frost or ice buildup anywhere on your air conditioning system, this is a cause for concern. Read on to learn about five reasons why air conditioners freeze and some tips on what you should do if you see frost or ice on your cooling system.

1. Dirty Air Filter or Coils

A clogged air filter is a common cause of a frozen air conditioner. When the air filter is filled with debris, no air can pass through it. This hinders circulation around the evaporator coil. Without a constant supply of air passing over it, the evaporator coil will freeze. Be sure to check the air filter monthly, and replace it as soon as you notice debris or buildup. A dirty evaporator coil can also cause the air conditioner to freeze. During a maintenance visit, technicians clean the coil. If you missed an annual tune-up of your cooling system, a lot of dust may have accumulated. The dust interferes with the ability of the refrigerant to absorb heat from the air in your home. Moisture will condense on the coil’s surface, and it will freeze.

2. Malfunctioning Air Handler Fan

If the air handler’s fan isn’t working properly, it can’t blow warm air from your home across the cold evaporator coil. When the refrigerant in the evaporator coil isn’t able to absorb heat, it keeps getting colder. This will cause the condensation to freeze on the coil. At the end of a cooling cycle, you may notice frost or ice. The ice may melt between cooling cycles, so you’ll end up with a puddle on the floor by the air handler.

3. Clogged Condensate Line

The condensate line drains the moisture that condenses out of your home’s air during a cooling cycle. Over time, mildew, algae or mold can grow in the condensate line. This may form an obstruction. Technicians always clean the condensate line during routine air conditioner maintenance. If you’ve missed an annual AC maintenance visit, a clogged condensate line could allow water to pool in the pipe and AC drain pan. If the water continues to accumulate, it may approach the evaporator coil. This is the coldest part of the air conditioner, and it may freeze the pooled water.

4. Refrigerant Leak

A refrigerant leak causes the air conditioner’s tubing to lose pressure. When the pressure is low, the refrigerant gets very cold. The moisture from your home’s air will condense on the cold coil and freeze. Refrigerant leaks are an environmental and safety issue. Only certified heating and cooling technicians should measure the refrigerant level. If the system has a leak, it must be repaired. Refilling a leaky refrigerant line will just result in continued leaking and freezing of the air conditioner’s coils.

5. Thermostat Problem

The thermostat is the air conditioner’s control center. It senses the temperature in your home. The sensor communicates to the air conditioner about when to start a cooling cycle and when to end it. A thermostat problem could result in a delayed signal to the air conditioner. This will make the air conditioner cycle too long. If the air conditioner’s cycle is too long, the coils can freeze. A thermostat repair or replacement may be needed if its sensor or wiring has failed.

What to Do If Your AC Freezes

So now you have a pretty good idea on what causes an air conditioner to freeze up. Here’s a few things we suggest to do. If you notice frost or ice buildup on any part of your air conditioner, wait for the cooling cycle to end. Turn off the system. After ruling out a dirty filter and checking the condensate line for clogs, schedule a prompt air conditioner repair. Operating the air conditioner with a refrigerant leak, thermostat problem or broken fan could result in a total system failure.

O'Brien Heating & Air Conditioning is the trusted provider of air conditioning repairs in Drexel Hill. We also offer heating repairs and heating and air conditioning maintenance and replacement. Our water heaters and indoor air quality services keep you comfortable all year long. For more details about why air conditioners freeze up and what to do if you see ice or frost on your cooling system, reach out to us at O'Brien Heating & Air Conditioning today.

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