Why Is My Air Conditioner Running Constantly? A Florida Tech Answers

July 06, 2018

It’s common for ACs to run non-stop during hot summer days in Florida.

However, if your AC is running constantly and it’s not overly hot outside, that’s definitely not normal.

In the worst-case scenario, your air conditioner is running all the time because of 1 of these 4 problems:

  1. Your AC isn’t getting enough air

  2. Your AC system is dirty

  3. You have a refrigerant leak

  4. Your AC is old or undersized

All of those issues require a professional’s help to fix. However, there’s one thing you should do before you call a pro...

Already sure you need a pro?

OR visit our AC repair service page for more info.

Before you call a pro: Check your thermostat

First things first: Before you pick up the phone to call a pro to look at your AC, go to your thermostat.

Is the fan setting set to ON instead of AUTO?

If so, that could be what’s causing your air conditioner to run non-stop. You see, when you set your thermostat to ON, it tells the blower to run constantly—even if your AC isn’t actually cooling your home’s air.

So, if your thermostat is set to ON, switch it to AUTO. The AUTO setting tells your AC blower to run only as needed, which cuts down on cost and noise.

Is your thermostat set to AUTO, but your AC still running constantly?

Then you may have one of the following problems...

Problem #1: Your AC isn’t getting enough air

One of the most common problems that causes an air conditioner to run non-stop is low airflow.

You see, your AC system needs to “breathe in” air to cool. If your AC is struggling to pull in enough air, then it will compensate by running longer.

As a result, this low airflow problem raises your energy bills (because the system is using more energy) and you could end up with other issues like a frozen evaporator coil.

The following issues can limit airflow to your AC:

  1. Clogged air filters

  2. Blocked/closed air vents

  3. Leaky air ducts

  4. A faulty blower fan

While the last two issues require professional services to repair, you can fix the first two:

Check your air filter

If your air filter is dirty (like the one pictured below) it is blocking air from entering your AC, so you should replace it. If it’s clean, or you changed the filter and your AC is still running non-stop, then contact a professional for help.

clean vs dirty air filter

Clean vs dirty air filter

Open all of your vents

Blocked or closed air vents restrict air from entering into your AC. Make sure all of your supply and return vents are open and unobstructed.


Return vent

Supply Vent in House

Supply vent

Problem #2: Your AC system is dirty

If your AC system gets dirty, it will make your system work harder to cool your home’s air.

When we talk about your AC getting dirty, we’re talking about 2 places in particular:

  1. The evaporator coil

  2. The condenser coil

The evaporator coil

The evaporator coil (located in your indoor unit, pictured below) is the part of your air conditioner that absorbs the heat from your home’s warm air, which is how you get cool air.

Evaporator Dehumidification Process

Warm air enters and gets pulled over the evaporator coil, then pushed back into your home as cool air

Over time, dust can collect on the evaporator coil, which creates a barrier between the cold coils and the warm incoming air. This barrier makes it harder for the evaporator coil to absorb heat, which means your AC will run longer to compensate.

A professional will need to clean your evaporator coil if it’s dirty because the coils are very fragile.

Besides your AC running constantly, signs you have a dirty evaporator coil include:

  • Warm air coming from the vents

  • A moldy smell near your indoor air handler

The condenser coil

The condenser coil (located in your outdoor unit) is the part of your air conditioner that dumps the heat collected from your home’s warm air outside.

Since the condenser coil is located outdoors, it’s prone to getting covered in dust and debris (see image below).

Dirty and Eroded Condenser for AC

A dirty condenser coil

So do this: Go outside and look at your outdoor unit. Take out any sticks or leaves that have wedged themselves into the unit. If you notice a thick layer of dust on the unit, you can use a hose on a low setting to try and clean the coils (be careful, though, the coils are fragile). If you don’t feel comfortable cleaning the coils yourself, contact a professional to clean them for you.

Problem #3: You have a refrigerant leak

Refrigerant is the liquid/gas that absorbs the heat of your home’s warm air at the evaporator coil. If your system is low on refrigerant, then your AC will run longer to cool your home’s air.

Refrigerant runs in a closed loop—meaning it never runs out unless there’s a leak in your system somewhere. So, if you have low refrigerant, then you know you have a leak.

Read our article, “5 Signs Your Home’s AC Is Low On Refrigerant.”

If you do have a refrigerant leak, a professional will need to repair it. Only a certified professional should handle refrigerant since it can be harmful to humans.

Problem #4: Your AC is too old

If your AC is too old (10+ years), then it may be running constantly because the system is losing efficiency. You see, as components within an air conditioner wear down over time, they cause the AC to lose efficiency which means it takes longer to cool your home.

In the long run, it’s better to replace an older AC rather than pay more in higher energy bills and frequent repairs. So if your AC has crossed its 10th birthday and you’ve already noticed that it’s struggling to cool your home, contact a professional to get recommendations for a new AC system.

Related reading: How Much Does it Cost to Install a Central AC in Tampa, FL?

Need a Tampa professional to fix your AC?

We’ll send over one of our trusted techs to fix whatever is causing your AC to run constantly.

In the meantime, visit our AC repair service page to learn what to expect when you hire us.

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