Should my HVAC Fan be Turned to On or Auto? | Air Experts
On or Auto setting

If you’re a homeowner, you may be wondering if it’s better to turn your thermostat to the “on” or “auto” setting. It can be confusing to know which of these settings to use, especially if you don’t understand the difference between the two.

What does “Auto” Mean?

Turning your HVAC fan to auto means the fan will only run when your system is running. Once your thermostat has reached the set temperature, everything, including the fan, will shut down. There are pros and cons to turning your fan to auto.


  • You can save a lot of money on your energy bill with the auto setting.
  • You can save time by having to replace your air filters less often.
  • You will have better control over the temperature of your home.


  • Cold or hot spots in your home because the fan stops pushing air through your house when the set temperature is reached, this means that the air may not have reached all the rooms.
  • Your motor to the fan might wear out faster if you leave it on auto because of all the stopping and starting.
  • Your indoor air quality might suffer more than if your fan was in the one setting.

What does “On” Mean?

When your HVAC fan is in the on setting, the fan is constantly blowing. Even once your set temperature has been reached, and the system is not cooling or heating, the fan is still pushing air through your house. Just like the auto setting, there are both pros and cons to turning your system to on.


  • The temperature in your home will be distributed more evenly, meaning fewer hot and cold spots.
  • Your indoor air will be cleaner because air is consistently flowing through your home’s air filtration system.
  • You can extend the lifespan of your HVAC fan by avoiding the wear and tear of auto.


  • You will have to change your air filters more often due to the amount of air constantly blowing through them.
  • You will have higher energy costs because the fan is always running.
  • You might have to maintain your HVAC system more regularly due to increased malfunctions because the fan is always on.

Choosing the Best Option for Your Home

Deciding whether you want to turn your HVAC fan on auto or on comes down to your personal preferences and your family’s needs. If you have allergies, leaving your HVAC fan in the on setting will help clean the air and reduce your symptoms. But if you’re looking to save money, the auto setting might be the better option for you. Considering the pros and cons of each setting, you can make an informed decision that is best for your home.

The best way to save money and keep your HVAC running smoothly is to keep up with your maintenance. Call an Air Expert HVAC tech at (732) 759-0934 to schedule a service today.

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