So you’re wondering how to fix a frozen air conditioner, or if you can even fix it yourself. It sounds strange that a central air conditioner working to cool your home in the hottest months of the year could freeze. However, many homeowners end up with this uncomfortable issue every year. Learn how to identify and fix this issue below.

How do I know if my air conditioner is frozen?

The first thing you may notice when your air conditioner is frozen is that your home is getting warmer and more humid. If you have a two-story home, you may notice this change more quickly upstairs. Another tell-tale sign that indicates a frozen ac unit is ice buildup on the outdoor unit.

If you feel warm air coming out of your vents, you’ll need to check your system. Open or unscrew the access panel to the evaporator. If any of the equipment or panels are covered in ice or the ac coils are frozen, then your system’s refrigerant may have fallen below 32 degrees, resulting in a frozen AC.

What causes an air conditioner to freeze?

There are many reasons an air conditioning system might freeze. These are the most common reasons:

  • Poor airflow
  • Dirty air filter
  • Low refrigerant lines
  • Faulty blower fan
  • Clogged condensate drain line

How to Fix a Frozen HVAC Unit

Since a frozen air conditioner can be caused by many different issues, it is possible that you’ll need an HVAC technician to tackle the job. However, there are some things you can try first, before calling an HVAC specialist.

1. Check the Vent Filters

If you have a clogged vent filter it is probably restricting airflow. If filters look dirty, go ahead and change them and see if that fixes the problem. A dirty filter can cause all sorts of problems, so make sure you inspect and change your filters regularly.

2. Inspect the Coils and Fins

Go ahead and also inspect the coils and cooling fins around the evaporator. Dirty coils create issues in the efficacy of the system. If look like they need cleaning, use a soft brush and gently remove any dust or debris. Check to see if all the supply registers throughout your home are open so you’re not restricting airflow, which puts extra stress on the system.

3. Check Coolant Levels

Low coolant can alter your a/c system’s pressure and cooling efficiency, which can cause the unit to freeze. You’ll need a coolant installation kit at your home improvement store to check your system’s refrigerant levels and correct them if needed. If your refrigerant levels are low, you may have a leak. You will need to contact an HVAC professional to fix this issue.

4. Reset the Power

After the ice melts and you’ve taken all the above steps to try to remedy the problem, you’ll need to restart your system to see if it’s functioning properly. Restore power and turn the thermostat to the cooling mode. After a few minutes, you should be able to feel cool air blowing from the vents before the end of the cooling cycle. If not, there may be additional damage to the unit or a refrigerant leak, and you’ll need to contact a professional HVAC technician for help.  

Even if your unit seems to be working normally, it still may be a good idea to double check with an HVAC service appointment and confirm the main cause of the HVAC issues. AC problems should be managed immediately to prevent further damage to the components of the system.

How to prevent a frozen AC in the future

Your HVAC system works hard. For many months out of the year, it is running the majority of the day, every day. and requires regular maintenance to continue working properly and efficiently. Dolphin Cooling offers maintenance plans to ensure that our customers are protected from issues like a frozen AC through regular prevention measures. Some things that you can do to prevent a frozen AC in the future:

  • Keep shrubbery and trees trimmed away from your heat pump and make sure all loose debris are removed from the area at all times.
  • Replace your air filters regularly (at least every 90 days, 45 if you are an allergy sufferer or have pets).
  • Keep all of your vents open for proper airflow and circulation and make sure vents are not blocked by furniture.
  • Consider an annual inspection to stop problems before they start.

Dolphin Cooling Maintenance Plans

Our maintenance plans offer something for everyone and focus on extending the life of your unit. Maintenance includes inspection of your air handler and condensing unit, cleaning the drain line, and more. You can get full details about our plans on our website. Call us for more information or to schedule service for your air conditioner unit at (239) 596-9044 or request an appointment online.