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Why Is Air Conditioner’s Refrigerant Line Covered in Ice?

Why Is My Air Conditioner’s Refrigerant Line Covered In Ice?

Are you here because your refrigerant line is covered in ice, and you are clueless about what to do next?

Home appliances can sometimes be tricky to understand and hard to manage until you know the underlying cause of the problem. When you correctly identify the problem, it becomes easier to find a solution.


Accumulation of ice on the lining of your AC can be a sign of an internal problem.

Let’s quickly have a look at the potential problems that can lead to this:

  • The Coil of the Evaporator Gets Too Cold
  • Filters are Blocked
  • There’s Low Refrigerant Charge
  • An Internal Component of AC is Broken

We’ll take you through some easy fixes to solve this issue.

Let’s move ahead toward the causes that lead to the formation of ice over the lining of your air conditioner.

4 Main Causes of Icy AC Line

Main Causes Of Icy Ac Line

Finding the right cause for the freezing refrigerant line can be confounding, but you can rule out the following causes one by one to know the actual cause. Without further ado, let’s take a deeper look at these causes:

1. The Coil of the Evaporator Gets Too Cold

The Coil Of The Evaporator Gets Too Cold

The evaporator unit is the primary suspect, damaged or disturbed when the AC shows ice all over its lining.

It messes with temperature regulation, as a result of which, there is a drastic temperature change between the internal and external environment.


An evaporator coil is the core part of the air conditioning system that manages the temperature. It absorbs the temperature while sending the processed air through the vents.

The internal temperature goes so low that the air starts to condense, and it reaches a point where ice formation begins to surface on the lining of the air conditioning system.

Ensure you get your evaporator unit professionally checked if you face such a complaint.

2. Filters Are Blocked

Filters Are Blocked

Next in line is the cause you can easily detect and get fixed at home. You will need to unscrew the outer shell of your indoor unit, bring the filters out and carefully analyze them for any signs of damage or blockage.

The filters might have gotten dirty over time, blocking the flow of processed air throughout the system and accumulating ice. When the filters block the refrigerant, the internal temperature drops, leading to this situation.

A thorough glance at the filters will tell you whether they need cleaning. You should roughly be able to see through those filters to ensure they are not blocking anything.

3. There’s Low Refrigerant Charge

There's Low Refrigerant Charge

The decreased level of the refrigerant leads to a lower charge on it. The reasons include damage to the airway and a puncture in the pipeline of your AC.

When this happens, the pressure inside the AC unit starts to drop. The temperature also begins to drop to a point where the internal air condenses slowly to balance the pressure. As the process progresses, the air inside the air conditioning system becomes so cold that it starts to freeze.

This leads to the formation of ice. When the ice starts to build up inside the system, it slowly outgrows the internal peripheries and extends its borders to the outer lines of the AC.

Consequently, you start seeing the ice on the outer lining of the refrigerant. You will have an AC specialist confirm if there is any leakage of your refrigerant.

4. An Internal Component of AC Is Broken

Broken/Damaged Condenser Coil

Lastly, if everything is ok with the evaporator coil and refrigerant, there might be an issue with any of the other internal components of your AC system.

This is the cause that would take the longest to confirm because professional technicians will need to check your whole air conditioning system.

A problem with the condenser coil, expansion valve, compressor, or evaporator coil could interfere with the AC’s normal functioning.

Some Quick Fix Tips

Ac Evoprator Coil Cleaning

Now that we have discussed the problem areas that could make your AC lining icy. Let’s dive into some tips to help you fix these issues the fastest way possible.

We have arranged these tips from easiest to most difficult concerning time, effort, and skill.

1. Try Restarting Your AC

Try Restarting Your Ac

Sometimes, the solution can be as easy as restarting your AC. All you will need to do is turn your AC off for some time and turn it back on.

If there is a minor issue, it will be automatically resolved via restarting.

However, if the problem is severe, you might need to try the next fix.

2. Unclog or Replace the Filters

Unclog Or Replace The Filters

You will want to unscrew the outer part of the indoor unit of your AC and get the filters out. Clean them thoroughly until there is no dust left on them.

After cleaning them, put them back on and restart your AC system. This fix will work if filters are the problematic area.

Otherwise, you can try the following last hack.

3. Don’t Forget To Thaw Your AC

Don't Forget To Thaw Your Ac

Thawing works like a charm in case of ice deposition.

You would want to follow the following steps to thaw your air conditioning system correctly:

  1. Turn off the thermostat of your temperature regulation system.
  2. Check the drainage pan and make sure that it is appropriately draining.
  3. Use cleaning tablets to clean the system and leave it smelling fresh.
  4. Wait for a few hours and let the cleaning do its magic.
  5. Turn it back on.

If your temperature regulator still acts up after following all the techniques to fix the issue, it might be a sign that you need to hire a professional at this point.


The icing of the refrigerant line in your AC can occur for any reason, from a disturbed evaporator coil to damaged internal components.

It can also be due to clogged filters and decreased refrigerant.

You can easily tackle this issue by using the infamous thawing method, replacing the filters, and restarting the AC.

Frequently Asked Questions

How To Stop Ice Forming in AC?

You can try restarting your AC and replacing the filters. If that doesn’t work, try thawing your air conditioner or call a professional for help.

What Is the Reason for Ice Formation in the Indoor Unit of Split AC?

It can be due to leakage or decreased refrigerant. Moreover, any problem with the indoor fan or expansion unit can also lead to ice formation.

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