How to Diagnose and Fix a Frosty Air Conditioner

You’re in your home in the middle of the summer with the air conditioning on full blast, but you notice that it’s definitely not working efficiently because you’re still sweating.

You go to have a look at your unit and you see ice. What’s the deal here? Why is your air conditioner freezing while you’re inside sweating?

Let’s take a look at what you can do to diagnose your frosty air conditioner and get your home back to your desired temperature:

Is Your Air Conditioner Frozen?

Luckily, a frozen air conditioner isn’t a difficult thing to spot. First, you probably notice it’s warmer in the house than you’d like so you turn down the thermostat. You wait a while, but discover the temperature isn’t cooling down.

You decide to take a look at your air conditioner to see if something is wrong and then you see ice buildup. That’s all there is to it in most cases.

Another way to notice this problem is by placing your hands over the air registers and feeling to see if the air is coming out cool as its supposed to. If not, you’ll want to take a look at your unit. If you can’t easily see the ice, you should use your system diagram to find out how to unscrew the panel to the evaporator and see if ice is present.

You could see ice on the panel, ice on the coils inside, or you may notice the refrigerant is reading below 32 degrees.

Now that you’ve determined you have a frozen air conditioner what do you do?

What Makes Air Conditioners Freeze?

There are actually several reasons your air conditioner could be a little frosty:

• Low refrigerant
• Poor airflow, especially to the evaporator coil
• It’s too cold outside (no, really)
• Various mechanical failures

Fixing a Frozen Air Conditioner

In many cases, fixing a frozen air conditioner is something that a professional HVAC technician will need to do. However, there are some things you can try first, if you want to:

1. Change the filters: Dirty and clogged filters can cause the air conditioner to freeze. Check your filters and change them if they look dirty to see if this fixes the problem.
2. Open all air supply registers: Make sure every air supply register vent is open in every room. Closing the registers restricts air flow and can affect the temperature of the evaporator.
3. Clean the coils and fins around the evaporator: Take a soft brush to remove any debris or dust to see if that helps any.
4. Give it time to thaw and cool properly: Once you’ve done any or all of the things above, you’ll have to wait a bit to see if the unit is thawing out and begins to cool again.

If you’ve tried the above steps and find out that your air conditioner is still frozen, you’ll want to contact a professional air conditioning repair service and have them come out and inspect and repair your system.

Having a frozen air conditioner is not something you’ll want to try to let go and ignore, hoping it will get better. Neglecting a frosty air conditioner won’t just mean you’ll suffer through hotter weather—your dripping air conditioner can also cause water damage to your home.

Troubleshoot if you can, but don’t be afraid to call for help.