Noticed ice building up on your AC unit and wondered what’s going on? It may look strange, especially in the middle of summer. After all, your air conditioner is supposed to cool your home, not turn into a freezer. So what causes this?

In many cases, frozen evaporator coils point to airflow problems. And one of the biggest culprits behind poor airflow is a failing blower motor. Let’s break this down in a simple way so you know what to watch for.

Why Do Evaporator Coils Freeze?

Your AC works by pulling warm air from your home and passing it over cold evaporator coils. This process removes heat and cools your space.

But what happens if warm air is not moving properly?

When airflow is restricted, the coil does not absorb enough heat. This causes the temperature of the coil to drop below freezing. Moisture in the air then turns into ice on the coil surface. Once ice starts forming, it spreads quickly and blocks airflow even more.

How The Blower Motor Causes Ice Formation

The blower motor is responsible for pushing air through your system. If it slows down or stops working, airflow drops significantly.

Here is what happens step by step:

1. Less air passes over the coil
2. The coil gets too cold
3. Condensation freezes instead of draining
4. Ice builds up and restricts airflow further

This cycle continues until your system can no longer cool properly.

Signs Your Blower Motor May Be The Problem

Not all frozen coils are caused by blower issues, but certain signs point directly to it.

Look for these clues:

• Weak airflow from vents, even with a clean filter
• No airflow at all while the system is running
• Strange noises like humming, rattling, or squealing
• Burning or electrical smells from vents
• Fan turning on and off unpredictably
• Circuit breaker tripping frequently

If you notice more than one of these, your blower motor likely needs attention.

Simple Checks You Can Try First

1. Replace your air filter
2. Let the ice fully melt before restarting the system
3. Set the thermostat to fan-only mode

If the fan does not run or the airflow is still weak, the blower motor or its components may be failing.

Trust Local Experts To Fix It Right

In hot areas like Austin, your AC works hard almost year-round. That makes blower motor issues more common than you might think.

Service Wizard Heating and Air Conditioning specializes in diagnosing airflow problems quickly and fixing them the right way. Whether it is a blower motor repair, capacitor replacement, or full system check, our team ensures your AC runs efficiently again.