Fixing Your Frozen AC Unit In 3 Steps

Written on: May 10, 2019

a/c repair connecticut


One of the most common air conditioning malfunctions homeowners face is when their AC unit freezes up. Even though the frosty failure leaves solid ice on your unit, don’t be fooled, the issue will cause your home, and perhaps your temper, to heat up.

Follow this guide to identify why your AC unit is frozen, and how you can fix it.

What causes an AC unit to freeze up?

Regardless of if you have a window AC unit or a central air conditioner, the reasons behind your AC freezing up are likely the same, as are the solutions for fixing it.

The root cause for your AC freezing up is usually the manipulation of the Joule-Thomson Effect, which is the principle of thermodynamics that allowed us to create an air conditioning unit in the first place.

Stick with us, we won’t get too technical here.

The Joule-Thomspon Effect

The Joule-Thomson Effect is a theory that describes how the flow of gas and pressure work together. In short, the method says that if gas expands, then pressure and temperature will decrease as a result (and vice versa). This is important because your air conditioner works by the evaporator coil expanding refrigerant (the liquid agents that make your AC work) to absorb heat in your home, and then pushing cool air out as a result.

So, your air conditioning unit expands refrigerant and decreases the temperature, sometimes causing it to malfunction, and a frozen AC unit is the result.

The common culprits of a frozen AC unit

Though the process seems complex, the common causes are quite simple.

How can you fix a frozen AC unit?

When caught early, fixing your frozen AC unit is often a simple solution. Follow the steps below to determine the issue so you can take action.

Step one: Unthaw your AC unit

If your AC unit is frozen, take steps to unthaw the unit and let the coils dry. To do this, simply switch your thermostat to ‘off’ and your fan to ‘on.’ This will minimize further damage and let you get a better view of what’s happening to your machine.

Step two: Find the underlying cause
Step three: Ask for help

If you’re unable to diagnose why your air conditioner is freezing up, or if you notice issues like a leak that requires specialized attention, be sure to consult with an AC professional.

Not only will the pros be able to accurately assess the issues, but they will also be able to provide you an estimate for repairs or help you upgrade to a newer unit, which might be more energy efficient. They’ll help you determine how your return on investment will look over time. This will help you make an informed decision about how to move forward.

How to prevent AC issues before they arise?

It’s also wise for homeowners to schedule professional tune-ups on all heating and cooling equipment in your home to decrease significant issues that could cause you to replace your home appliances prematurely, and also ensures your systems are effectively functioning, which can reduce your bills.

For homeowners in the Fairfield and New Haven Counties in Connecticut, Santa Energy has been a reliable HVAC company for over 75 years. If you have any issues with your air conditioning unit that you’re unable to solve, we’re happy to help.