Having your central air conditioner freeze up in the middle of the winter is annoying. But what to do when your AC unit freezes up during the hottest summer days?
You might be surprised, but many people are faced with this problem even in the summertime. Do you want to prevent these issues and improve the indoor air quality of your HVAC equipment? What if your AC unit is already frozen?
Keep reading, and you’ll learn what causes freeze-ups and how to keep your AC from freezing up in the future.
Reasons What Causes The Air Conditioner to Freeze Up
So, you’re probably wondering why does your air conditioner freeze up despite the hot weather? Here are the most widespread reasons:
- Dirty air filters. Filters allow the warm indoor air to pass through the unit to the outside. This both regulates the room temperature and warms the cold refrigerant in your AC. So, clogged air filters prevent your unit from warming up, which often makes HVAC iced up.
- Insufficient refrigerant. The evaporator coil inside your AC unit won’t correctly warm up if the refrigerant is leaking or incorrectly charged.
- Drainage issues. Hot air that gets inside the HVAC unit condenses into water and flows out through a drain pan. However, if something blocks the drain, the water will eventually evaporate again and might freeze on the evaporator coil.
- Thermostat malfunction. Your system may run more than necessary if the built-in thermostat shows an incorrect temperature, which causes other issues that lead to a freeze on AC.
- Blocked supply registers. The HVAC may also freeze if you close too many supply registers. So, keep at least three-quarters of your registers open to prevent such issues.
Now you won’t have to ask yourself: “why did my air conditioner freeze when it’s 90 degrees Fahrenheit outside?”
Next, let’s see what you can do if your unit has already frozen.
What to Do When Your AC Unit Freezes Up in 4 Steps
So, you’ve identified that your outside air conditioner unit is frozen. Here’s how you can fix it without calling in professional technicians:
Step 1. Shut off the air conditioner from the power
You should avoid using the AC while it's frozen up inside because it wastes the electrical power and may damage the compressor (the most expensive part). So, start by disconnecting the unit from the power by turning off the electrical breaker.
Step 2. Melt the ice on the evaporator coil
You should wait for the frozen AC to thaw. However, waiting can take a whole day, even on a scorching summer day.
If patience isn't your strongest suit, there are ways to unfreeze AC units fast by using a blow dryer on the evaporator coil. Just don't try to break the ice physically, as it may damage the fragile components of the device.
Step 3. Clean the evaporator coil
After the ice is gone, you need to clean the parts of the AC unit from blockages. Carefully wipe the evaporator coil with paper towels.
You should also empty the drain pan and check if the air filters need replacement to prevent the freeze on the air conditioner from recurring.
Step 4. Let the AC unit dry
Make sure the AC unit is dry before using it for temperature control. You can set your thermostat to “fan-only” or “blower” for a few hours to speed up the process. After doing all of the above, your air conditioner should be working as usual.
You probably want to ensure your air conditioner won’t freeze up again. Continue reading to learn how.
How to Keep Your AC from Freezing Up
If you've had to unfreeze your AC once, you probably wouldn't want to do it again. Thankfully, you don't have to regularly melt the ice inside the AC unit if you follow our recommendations.
Replace the air filters
As a general rule, make a habit out of cleaning air filters in your AC units. Better yet, change your filters before they start affecting the performance of your machinery.
How often should you replace your filters? Optimally, you should replace them at least each quarter. You may change them more frequently based on:
- The type of your air filter and HVAC unit
- The indoor space
- Number of pets and children living in the house
- Whether someone smokes indoors
Check the refrigerant levels
Refrigerant is an extremely cold matter used to control the indoor temperature. If your AC is low on refrigerant, the evaporator can eventually be covered with ice. At the same time, a leak in the system can lead to refrigerant freezing your air conditioner.
You should check the refrigerant in the HVAC units at least every six months to see if they're at an optimal level. If you don't like doing it yourself, you might order a technician to look for potential leaks.
Inspect the blower fans
The condition of your blower fans and motor affects your HVAC performance. We recommend hiring a technician to check the age and wear of your fans, their rotation speed, and power output.
Replacing a faulty blower can prevent the AC unit from freezing up and reduce the risk of damage to your equipment. That's why you should look over them at least once a year.
Unblock the air vents
Blocked air vents can restrict the airflow and cause problems with your HVAC system. So, take some time to ensure your furniture and curtains don't block them. And don't forget that you shouldn't close more than a quarter of your supply registers to prevent the central air conditioner from freezing up.
Clean the drain line
As we mentioned, the water inside the HVAC unit won’t flow out if the system is clogged. So, you should inspect the drain pipe for any blockages, excess dirt, and debris.
Clean the drain line and anything that might prevent the normal water flow. It's better to do it with a paper towel or use a wet and dry vacuum.
Don’t set the temperature too low
Setting the AC unit temperature too cold when it’s blistering hot outside will strain your device. As you know by now, this leads to malfunction and freezing up.
Even though it's tempting, you should refrain from relying on AC units to cool you off. The same can be said about using air conditioners non-stop. Instead, we recommend finding other ways to lower the temperature in your house (such as fans).
Conclusion
Most problems causing AC units to freeze are preventable with regular maintenance. You should keep most of your air vents and supply registers open, check the drain line and blower fans, and don’t neglect to replace filters.
Everything we’ve described is easy to handle with a little effort. So, you won’t have to worry about your AC freezing up without spending money on service technicians. And if you wish to improve your indoor quality DIY, make sure to check Blackhawk Supply for premium HVAC equipment and supplies!
