Air Conditioner Evaporator Coil Frozen: 7 Causes and Fixes

A frozen evaporator coil in an air conditioning system means more than a busted component that hinders a comfortable home; it’s a sign of urgent problems. Air conditioner evaporator coil frozen issues, such as ice buildup, undermine the performance of your system, raise energy costs, and may cause irreversible harm.

What is an Evaporator Coil?

When the operating conditions are right, the coil provides a proprioceptive temperature and air. However, this is worked off by a frozen air conditioning evaporator coil, which may cause you to end up with warm air instead of the cool air that you wanted. If not repaired, it causes a lot of inconvenience, although even these are more so in the long run and may harm the car.

1. Restricted Airflow

Cause: Blinds, furniture or other obstructions, a dirty filter or a clogged vent, or a faulty blower can cover the evaporator coil and limit airflow over it. If there is inadequate airflow, the coil cools down and freezes up.

• Air filters, especially the dirty ones should be replaced 1-3 monthly.
• Clean out or unclog any vents or air registers in your house.
• Ensure there is no mechanical problem with the blower motor and then fix if there is.
• Check to make sure no furniture or curtains are blocking the flow directly to and from the vents.

One of the primary causes of the air conditioner evaporator coil frozen problem is restricted airflow.

2. Low Refrigerant Levels

Cause: Refrigerant leak can make pressure in the system get low, hence freezing on the coil occurs.

• Hire an air conditioning technician to come to diagnose the problem and then have them fill it with the correct refrigerant.
• Make sure it does not leak to reoccur by keeping an eye on the system all the time.

Parts of the air conditioning system that might require proper quantities of refrigerant to the evaporator coil can cause it to freeze and typically require a technician.

3. Thermostat Set Too Low

Cause: Forcing the thermostat to the lowest temperature, if possible, causes the coil to freeze, especially during a humid climate.

• Generally, it is set at a moderate temperature, below 75° F though my preference is it being slightly lower at around 70° F.
• There is a need to have a fixed temperature inside the building through the use of a Programmable Thermostat.
• Ensure the heating and cooling units are not switched on either at very high or very low temperatures since this will exert stress on the system.

Thermostat misuse is an easily avoidable cause of an air conditioner evaporator coil frozen.

4. Dirty Evaporator Coil

Cause: Dirt and grime buildup on the evaporator coil insulates it, preventing proper heat absorption and leading to freezing.

• Turn off the AC and inspect the coil for visible dirt.
• Use a soft brush or commercial coil cleaner to remove debris.
• Schedule annual maintenance with a professional to keep the coil clean.

A clean coil is essential to prevent an air conditioner evaporator coil frozen situation from occurring.

5. Oversized or Undersized AC Unit

Cause: A unit that’s too large or too small for your space can cycle improperly, leading to insufficient airflow and freezing.

• Consult an HVAC professional to assess whether your AC unit is the right size for your home.
• Consider upgrading to a properly sized unit if necessary.
• Ensure proper insulation and sealing in your home to complement the unit size.

Improper unit sizing is often overlooked as a cause of an air conditioner evaporator coil freezing.

6. Faulty Fan or Motor

Cause: A malfunctioning fan or motor can prevent proper air circulation over the evaporator coil, causing it to freeze.

• Inspect the fan blades and motor for damage or wear.
• Replace faulty components to restore airflow.
• Ensure regular lubrication of moving parts.
• Schedule routine checks to identify early signs of wear.

Faulty fans or motors are mechanical issues that often lead to an air conditioner evaporator coil freezing.

7. High Humidity Levels

Cause: High humidity can stress the AC system because the discharged air will cause water to accumulate and freeze on the coil.

• Turn the air conditioner up to lower humidity inside the house.
• Continue to control airflow from one specific area such as the bathroom and kitchen which has high humidity.
• Inspect the flow of water to avoid accumulation of water around the coil.
• Use a simple instrument called the hygrometer to control the indoor humidity level.

High humidity levels not only contribute to an air conditioner evaporator coil frozen but also strain the entire HVAC system.

Signs of a Frozen Evaporator Coil

How do you know if your air conditioner evaporator coil is frozen? Here are some common signs:

• Reduced or no airflow from the vents.
• Warm air coming from the AC.
• Visible frost or ice on the indoor unit.
• Unusual noises or dripping water near the system.
• Increased energy bills.

If you notice any of these signs, it’s crucial to address the issue promptly. Ignoring the problem can exacerbate an air conditioner evaporator coil frozen and lead to more severe system damage.

How to Safely Defrost a Frozen Coil

Before fixing the underlying cause, you’ll need to defrost the frozen coil:

1. Turn Off the AC: Switch off the unit to prevent further damage.
2. Set the Fan to ON: This allows warm air to circulate and speed up the defrosting process.
3. Wait: Depending on the extent of freezing, defrosting may take several hours.
4. Inspect for Water Leaks: Check for water pooling near the unit as the ice melts.
5. Address the Root Cause: Use the fixes provided earlier to prevent recurrence.

Defrosting is a critical step in resolving an air conditioner evaporator coil frozen issue.

Conclusion

A frozen air conditioner evaporator coil is something not very good that should be fixed soon. Now that you know what causes them and these fixes you can fix your AC and save yourself from future costly repairs. In other words, it means you should not wait for the system to break down and then fix it; instead, some good maintenance work on the system will be ideal. The best approach helps to make your air conditioner evaporator coil frozen concerns a thing of the past since most problems are resolved immediately.

FAQs

Q1. When the evaporator coil in my air conditioner froze, why did it happen?

Four main reasons include inadequate airflow over the evaporator coil, lack of refrigerant, grille and coil dust, and extreme humidity.

Q2. Is it possible to run my AC with a frozen coil?

No, and you should switch OFF your air conditioning system whenever your coil is frozen, to avoid putting pressures on the system that will compel expensive repairs which may be very expensive to fix.

Q3. It should not take more than two hours to defrost a frozen evaporator coil.

This process may take several hours some few hours depending on the time taken to freeze the food. All these suggestions are derived from the observation that merely turning the fan of the mode to ON may accelerate the process.

Q4. Can a frozen evaporator coil be repaired without the help of an expert?

However, while simple tasks such as changing an air filter may be done on your own, other more serious problems such as refrigerant leakage and mechanical concerns will require help from a professional.

Q5. What can I do to avoid the situation of my AC freezing again?

These include; power washing, cleaning, and applying appropriate settings of the thermostat and ensuring proper air circulation can go a long way toward avoiding a frozen AC unit.

Do you have questions, or are you ready to start your next project? Explore our services at AiRCO Mechanical!