Energy Savings

Should your thermostat fan be set ‘On’ or ‘Auto’?

This is a great question and can vary depending on time of year and house layout. But lets start with how both of these features function.

Auto Setting for Fan: “Auto” means that the fan on the furnace comes on when the thermostat calls for heating or cooling. Once the thermostat reaches its set point the fan would shut off.

ON Setting for Fan: “ON” means that the fan on the furnace is on 24/7 and will remain on even after the set point is achieved. This helps circulate the air in the home 24/7 which can help with indoor air quality and filtration. It also can really help on two story homes to make a more balanced feel within the home. Basically the thermostat typically is located on the first floor and has no idea the upstairs or another part of the home is hot or cold. By running the thermostat on “ON” 24/7 it helps blend the air throughout the entire home to be more balanced. Variable speed furnace blower motors are something to consider as they will ramp the RPM’s down on the blower motor saving electricity. But even with a single or fixed speed blower motor its actually less wear and tear on the blower motor running 24/7. Kind of like a car its not the 500 mile road trip that’s hard on a car it’s the starting and stopping and short distances that causes more issues. Reports have shown that running your fan 24/7 is equivalent to a 30-40 watt lightbulb being on from an electricity usage standpoint.

At Plumbing Heating Paramedics, we typically recommend the homeowner run their fan on “ON” 24/7. But we would recommend trying both in your home and see which is better for you.