How Should I Unfreeze My AC Unit?

Alison Kasch
Written by Alison Kasch
Updated May 28, 2021
Air Conditioning Unit
Photo by adamkaz / iStock / Getty Images

Learning how to fix a frozen AC unit involves diagnosing the problem in 5 simple steps, followed by having a pro take care of any necessary repairs

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If your AC unit is frozen, don’t just let it go. Ice on your air conditioner unit usually points to blockages that can damage your system from restricted airflow. Instead, learn how to fix a frozen AC unit by checking and cleaning components and, in some cases, having a pro come take care of the rest.

  • Project difficulty: 2/5

  • Time: ~1 day

Tools Needed:

  • Soft brush or compressed air

  • Towel

1. Allow the Ice on the AC Unit to Thaw

If you’re wondering how to fix a frozen AC unit, your first step is allowing the ice to thaw. Hint: this is something you’ll want to take care of before calling in a pro, as there is quite a bit of waiting involved.

Shut the unit off at the breaker and wait for the ice on the evaporator coil to thaw, which may take up to 24 hours. You can also switch off the system while running the blower to encourage the ice on the AC coil to melt. Keep an eye on it and wait about an hour. Once the ice thaws, gently soak up the water with a towel and restart the system.

If it’s not immediately apparent that the evaporator coil is frozen, look for the following:

  • No airflow, despite the fan running

  • Condensate dripping while the AC isn’t running

  • Sweating on the sheet metal near the coil

Warning! Resist the urge to channel Yukon Cornelius: attempting to scrape, chip, or even melt the ice on your own won’t speed up the process. This will only end up damaging your unit’s components.

2. Examine Your Air Filters

Ice on your AC unit often points to blockages in airflow, which cause the unit to work too hard and become a glacier. Check out your unit’s filter and replace it if needed (trust us, you’ll know when it needs it). If this doesn’t prevent recurring ice on your AC lines, proceed to the next step.

3. Check the Coils

If you changed your air filter recently and you still see ice on the AC unit, your evaporator coil may have collected too much dust, dog hair, grime, and who knows what else. Just like a dirty filter, a dirty coil can also obstruct airflow, causing your unit to overwork and freeze up. Be sure the unit is off, then gently clean the coil with either a soft brush or compressed air.

Note: Do not use anything scrubby or abrasive on your evaporator coil, as this can damage it.

4. Observe Coolant Levels

Ice on your AC lines might also indicate low refrigerant. Contact a local HVAC company to check for leaks and, if need be, perform a freon leak repair. This type of AC repair costs between $225 and $1,600 depending on the leak’s location and severity.

5. Reset the System

When troubleshooting AC problems, you should always have the system fully shut off at the breaker. Once you’re done checking for issues, start the unit and the blower back up again. If you find ice on the AC unit again, compare quotes from top local HVAC specialists and have a pro take a second look.

How to Fix a Frozen AC Unit and Prevent It From Refreezing

Once you’ve pinpointed the cause of your unit turning into an icicle, maintain a consistent AC service schedule to keep components clean and to prevent ice on your AC unit due to freon leaks. This will also help you save money on AC costs by ensuring your system is running at its maximum efficiency. Otherwise, be kind to your system by running it consistently and leaving all important repairs up to the pros.

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