Why is My Air Conditioner Constantly Running? | Air Experts

If your AC is running constantly, there is likely an issue with your AC system. A few common explanations include:

  1. The thermostat fan is set to ON
  2. There is a blocked or dirty air filter
  3. Refrigerant levels are low
  4. The outdoor unit is blocked or dirty
  5. Your AC system is too small for your home

Below, we’ll walk through each of these issues and their respective solutions to help you troubleshoot why your AC is constantly running.

Issue #1: The thermostat fan is set to ON

You might be thinking, “If I want my AC to cool my home, shouldn’t the FAN be set to ON?” Actually, the “correct” setting for the fan is AUTO.

When the fan is set to ON, your AC runs constantly, regardless of whether the air it’s blowing is cool air or warm air. When the fan is set to AUTO, it only circulates air that has been cooled.

If your AC is running constantly but isn’t always blowing cool air, this may be your issue. To fix this problem, check your thermostat and set the fan to AUTO, not ON.

Thermostat FAN set to AUTO

Issue #2: Blocked or dirty air filter

When your air filter is blocked or dirty, it reduces the amount of air that your AC intakes, which in turn limits how much cool air it can produce. This normally results in your AC working overtime to try and produce the right amount of cool air, which makes it seem like your AC is running constantly.

To fix this, check your air filter.

Clean air filter vs. dirty air filter.

If your filter looks like the filter on the right, it’s time to replace it. A good rule of thumb is to check your air filter every month during the summer and replace it if it’s dirty.

Issue #3: Refrigerant levels are low

As we mentioned above, your AC actually cools your home by removing heat from your home’s air. Refrigerant is the substance that carries this heat out of your home.

If your refrigerant levels are low, your AC is not able to remove as much heat as it usually can, meaning it has to run longer to produce the same temperature.

If this is your issue, you’ll need to contact a professional. When refrigerant levels are low, it means there is a leak in the system, and a professional will need to repair it.

Issue #4: Blocked or dirty outdoor unit

Once your home’s air has been stripped of heat, that heat is carried outside by refrigerant and dispersed via the outdoor unit.

If your outdoor unit is dirty or is blocked by debris, shrubbery, etc., your AC system will not be able to get rid of this heat as quickly as it needs to, and your AC will have to run constantly to keep up.

The fix? Gently clean your outdoor unit of any debris and clear away any plants that are growing within 3 feet of your outdoor unit.

Issue #5: Your AC is too small for your home

If you’ve recently had a new AC system installed, your AC could simply be too small for your home.

Before installing a new AC system, a technician should have evaluated your home and cooing needs. However, if they installed a system that’s too small, your AC is probably struggling to cool your home, which is why it’s running constantly.

If this is your issue, you should replace your AC system with one that is properly sized for your home.  

Breathe easier. Hire New Jersey’s best AC techs!

If your AC is running constantly, it can result in higher energy bills and long-term damage to your AC system. The best approach is to schedule an appointment with a professional who can come to your home and accurately diagnose the issue.

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