It’s certainly alarming to wake up in the morning and find ice on the outside of your air conditioner. Especially after a night of poor sleep due to insufficient cooling. The good news is that your air conditioner freezing up at night may only require a simple DIY fix.

4 Causes of Your Air Conditioner Freezing Up at Night

There are several causes as to why your ac freezes overnight. We’ll go through each so that the source of the problem and how to fix it is clear. Since these causes can often be prevented with proper maintenance, a little knowledge will go a long way to stop your air conditioner freezing up at night.

#1 Air Temperature is too Low

An HVAC unit can be sensitive, requiring multiple factors to be in sync for it to run properly. If the air temperature outside is too low, the pressure inside the air conditioner can drop, causing the ac to freeze up at night. This is likely to happen in the spring and fall here in Atlanta when the days are warm but the nights become cool.

Fortunately, if a low outside temperature is the cause for your air conditioner freezing up at night the fix is easy: turn off the system at night and open the windows instead. Save the ac for the hot nights when you really need it.

#2 Low Refrigerant in AC

Typically you should add refrigerant to your ac system once or twice a year. If you find yourself doing this once or twice a season it’s likely a leak is to blame.

Given that air conditioners vibrate a lot, it’s not surprising when a component loosens, causing refrigerant to leak. This causes a chain reaction of events in which your evaporator coil’s pressure drops, causing moisture to collect and freeze outward.

This is a situation in which your ac needs repair. Dependable Heating and Air of Atlanta can fix the problem and provide proper maintenance to stop your air conditioner freezing up at night.

#3 Insufficient Air Flow/Dirty AC Coils

Your evaporator coil may freeze if there’s insufficient airflow throughout your unit. A dirty air filter is usually the culprit. A filter that’s too small or of poor quality can also be the cause.

Replace the filter at least every 3 months to prevent this common AC problem. If you continue to see your ac freeze up at night, there could be a blockage in your ductwork and a professional repair is required.

air conditioner freezing up at night

Photo Credit: Parker

#4 Contactor Stuck

When you ask, “How do I keep my air conditioner from freezing up?” you may not know a contactor is to blame. The contactor is a part on the outside of your unit that controls electricity levels to the AC’s components. If it becomes stuck, the outer portion of the ac will run continuously and freeze up.

If a stuck contactor is the reason for your ac freezing up at night the outside unit will continue to run even after you’ve turned the AC off at the thermostat. You’ll need to replace the contactor yourself or use a professional repair service.

We hope these ac freezing troubleshooting tips show that, with a little maintenance, your air conditioner freezing up at night can be prevented. If the problem persists or another crops up, Dependable Heating and Air is more than ready to be your ac repair service. Give us a call so you can always stay cool!