What Causes Your Evaporator Coils To Freeze and How to Fix It?

Ever noticed your air conditioner running, but your home isn’t cooling? If your AC isn’t blowing cold air, there’s a good chance your evaporator coils have frozen. Ice buildup on your AC unit is never a good sign, but don’t worry you’re not alone. Let’s break down why this happens and what you can do to fix it.

Why Do Evaporator Coils Freeze?

Your AC’s evaporator coils play a crucial role in cooling your home. They absorb heat from the air, allowing cool air to circulate. However, when something disrupts this process, the coils can get too cold and freeze. Here are the most common reasons why:

1. Restricted Airflow

Air needs to flow freely over the coils to keep them from freezing. If airflow is blocked, the coils can’t absorb enough heat, causing ice to form. This can happen due to:

Clogged air filters – A dirty filter blocks airflow, leading to frozen coils. Replace filters regularly.
Closed vents – If too many vents are closed, air won’t circulate properly.
Malfunctioning blower fan – If your fan isn’t working, the coils won’t get enough warm air.

2. Low Refrigerant Levels

Refrigerant helps transfer heat away from your home. If there’s a leak or your system is low on refrigerant, pressure drops inside the coils, making them too cold and leading to ice buildup.

3. Dirty Evaporator Coils

Dirt and dust can coat the evaporator coils, making it harder for them to absorb heat. Without proper heat absorption, moisture on the coils freezes, creating layers of ice over time.

4. Drainage Issues

Your AC removes humidity from the air, but if the drain line is clogged, water can back up and freeze on the coils.

How to Fix Frozen Evaporator Coils

If you suspect frozen coils, here’s what to do:

Turn Off the AC

Continuing to run your AC with frozen coils can cause serious damage. Switch it off immediately to prevent further issues.

Let the Ice Melt

Give your AC time to thaw naturally. You can speed this up by running the fan (without the cooling mode) to help warm air circulate over the coils.

Check and Replace the Air Filter

A dirty filter is an easy fix. Swap it out for a clean one and make it a habit to replace filters every 1-3 months.

Inspect the Vents

Ensure all vents are open and unblocked to allow proper airflow.

Look for Water Leaks

Check your AC’s drainage system for clogs and clear out any blockages.

Call a Professional

If your coils keep freezing, you might have a refrigerant leak, a broken blower fan, or another issue requiring expert attention. A trained HVAC technician can diagnose the problem and get your AC back in top shape.