dad watching his toddler wash his hands in the kitchen sink
Back to Blog

Should I Run My Heating On “Auto” Or “On” in the Winter?

A Smiling Man Adjusting Thermostat On Home Heating System

“Should I set my heating system’s fan to ‘auto’ or ‘on’ during the winter?” “Are there different rules for furnaces and heat pumps?”

These are two of our customers’ most frequent questions about keeping their homes cozy and comfortable during the colder months. The answer varies according to personal needs and preferences, but the choice is often clear if considering equipment efficiency. Expert heating services from Mattioni Plumbing, Heating, & Cooling include advising our customers on how to get the best performance out of their heating equipment.

Differences Between “Auto” and “On” Settings

The fundamental difference between the “auto” and “on” settings is that the fan runs continuously with the “on” setting, even if the heating unit shuts off.

  • The “auto” function allows you to control how long the fan operates. Once the set interior temperature is reached, the unit and the fan stop. This ensures the fan uses the minimum amount of energy and helps it last longer due to fewer starts and stops.
  • Fans set to the “on” function run continually, even after the desired temperature is reached, evenly distributing air and helping indoor air quality devices like UV filters and air scrubbers do their job.

There are advantages and disadvantages to both settings. For instance, setting the thermostat to auto prevents air from circulating when fans are off while running a fan continuously uses more power, which increases utility bills.

Which Fan Setting Is Best: “On” Or “Auto”?

While there are pros and cons to both settings, here at Mattioni, we typically advise customers to use the auto setting, and here’s why.

The damage to your heating system by turning on and off is generally negligible and can usually be prevented with seasonal furnace maintenance. Also, your potential energy savings are substantial compared to your spending if your system runs continuously.

Heat Pump Winter Settings

The “on” versus “auto” debate differs for heat pumps, which have a variety of settings, including heat, cold, fan, auto, and dehumidify. When choosing a mode for your heat pump, keep in mind the following:

  • It can be best to avoid the “auto” mode. Though it allows your heat pump to decide whether to heat or cool the space, it doesn’t always know best and might turn on the heat on a cool summer night or switch on the AC during a mild winter afternoon.
  • You can avoid accidentally cooling during winter by using the “heat” mode and during summer by using the “cool,” “dry,” or “fan” setting.

Why Your Fan Setting Matters

The winter fan setting you choose significantly affects:

  • How much money you spend
  • How much power your HVAC system burns
  • How often you need to change the air filter

It can also affect whether your home is heated evenly.

Choose Mattioni for Furnace Services

The bottom line? The best setting for your heating system’s fan is the one that saves you the most money while keeping your home comfortable. You might also consider installing a smart thermostat that turns your furnace or heat pump on or off as needed.

For over 75 years, Mattioni has delivered furnace services to our Chester County customers’ homes, ensuring their heating systems keep everyone inside cozy and warm.

Contact us online or call us at 610-400-8510 to schedule an appointment.

Ready to book
online now?
Use our scheduler!
VIP Membership With a low monthly payment, you’ll receive annual HVAC and plumbing inspections, discounts, priority service, extended warranties, and much more. For a limited time, save 30% on membership plans!
Proudly Serving Southeastern Pennsylvania Mattioni's Pennsylvania service area Downingtown | Kennett Square | Villanova |
Malvern | Newtown Square | And surrounding areas
Mattioni's Pennsylvania service area