4 Things to Know and Do When Your AC Freezes Up

Is your air conditioner freezing up? It can be surprising to see a chunk of ice sitting on your outdoor AC system, especially in the middle of summer. But sometimes you can’t even see the ice on the exterior of the unit.

While you may think something like this during the hottest days of the year is impossible, an air conditioning unit freezing in the summertime is something that happens frequently.

Continue reading to learn what causes it, and what to do if you’re experiencing a frozen AC system:

What does it mean for the AC to “freeze up”? 

Often, you will notice ice on the copper lines running from your outdoor unit to your indoor unit. In extreme cases, ice can be seen coming out of the indoor outdoor unit itself. This obviously is not a normal condition and you need to contact a professional AC company, but there are some things you can do before they get to your home.

What causes freezing up? 

Your air conditioning system is full of extremely cold refrigerant. When the coils are activated, the refrigerant will need warm air to blow across them. This cools your air and keeps the coils at a warm enough temperature that they do not freeze. The indoor coil removes heat from the inside air, and then will transfer it using the refrigerant to the outdoor coil which pushes the heat to the outside. The system is actually pulling heat from your indoor air and transferring the extra heat outside. This is why if you ever put your hand over the fan running on your outdoor unit the air feels noticeably hot.

However, if something in the air conditioner malfunctions, the whole system gets disrupted. If something prohibits the warm air from blowing over the coils, this causes the evaporator coil to allow the refrigerant to cool too much, causing it to fall below freezing and ice over. This is what we call a restriction in the system.

There are many causes of restrictions, but the most common are: dirty air filters, weak or failed blower motors, dirty evaporator coils, and low refrigerant. Each restriction has its own solution. Some are quick, inexpensive fixes and some can be complex fixes with higher costs. Luckily, the most common cause is the air filter, which is also the simplest fix.

What can I do? 

First thing you should do is go to the thermostat, turn the AC OFF and turn your indoor fan ON. This will start to melt the ice. The next step is to remove your air filter and see if it is dirty. If it looks bad, replace the filter and let the fan run until the ice is melted. Then run the AC again. If the ice comes back, call an HVAC professional. If the ice doesn’t come back, the filter is likely the cause of the freezing up.

Will I have to replace my AC system? 

There is no definitive answer, but most of the causes of freezing up are repairable and do not require an AC replacement. Always call an HVAC professional to come out and help you be sure. Gentry is happy to help.