Forezen aircon coil

Essential Guide to Aircon Freezing Up & How to Fix it

Air conditioners have many moving parts. These parts can break, get stuck, or just get clogged. Fans might stop moving. Filters can get clogged. Thinks can leak. Refrigerant lines might kink. Any of those situations might result in a pressure drop, which can let the refrigerant expand excessively, getting too cold, believe it or not.

Let’s learn more about frozen aircon.

Why Does My Aircon Keep Freezing Up?

In short, air flow blockage results in an aircon freeze-up. Air conditioners must have a steady airflow to prevent humidity from settling on their coils where they can freeze.

If you want to keep the airflow from your own home moving just enough to maintain your air conditioner’s functionality, you need to make sure that the air filters are clean and not getting clogged. This will restrict the airflow inside your home. Air filters can be pretty cheap, so it’s a good idea to change them out routinely.

Another good prevention of airflow issues and general problems is keeping the air conditioner cleaned and tuned up. The U.S. Department of Energy says that changing AC filters improve air conditioner efficiency from 5 up to 15 per cent.

How Will I Know My AC Froze Up?

There are three obvious signs that this has happened. First, your AC unit could have visible ice on it. Second, there might be a lack of any cool air; if you can put your hand near a supply vent and feel warm air going through, then you might have ice in the system somewhere. Third, you might hear a hissing sound coming from your unit.

How Long Will It Take My Air Conditioner To Unfreeze?

Your AC can take an hour to even a whole day to get totally defrosted. You need to catch this early if you want to prevent more damage to the unit. The blower motor in the AC pulls warm air from the interior of your home and then blows it over refrigerant coils that are part of the evaporator.

How Do I Fix My Frozen AC Coil?

As the coil will keep condensing water, there will inevitably be ice forming on the freezing coil surfaces. The problem is probably an airflow blockage.

The first step is turning off your air conditioner, so it has a chance to defrost. Once it’s had enough time to actually thaw, be it 1 hour or 3, just let the fan run for around an hour.

Install a fresh filter if the current one looks really clogged or very dirty. Change your air filter at this time. Review our other article about how and when you should change AC filters. After that, expect your AC to be back in normal working condition.

Can An AC Freeze Because of A Drain Clog?

When a condensate drain line clogs, it traps water inside the air conditioner. As a consequence, your evaporator coil will inevitably turn to ice. Drain line moisture can also freeze, and that will make your AC turn off.

Can My AC Freeze Because Of A Dirty Filter?

A dirty filter undergoes buildup over time, resulting in poor airflow of the cold air you want and need. If that cold air gets trapped inside the AC, it can make ice start forming on the coils. Once this happens, your AC can freeze up to the point of inoperability.


We’ve done the research for you, and we hope this article has provided a few answers to your questions about why an air conditioner can freeze up.

If you keep having this issue with your AC, then call us now for a free estimate on what we can do to help! We have over 18 years of experience as an AC company and will get right down there to find out why your unit is freezing up so fast before fixing it quickly. Our experienced team will ensure that nothing else goes wrong during our service by checking for any underlying problems or issues when they come out, too, like clogged drains or dirty filters. Call us today!

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