Running the fan on the furnace continuously (or fan on mode) offers several advantages. Firstly, it helps to distribute air more evenly throughout the home, ensuring consistent temperatures in every room. This can result in increased comfort for occupants, as there are no sudden blasts of hot or cold air when the furnace cycles on and off. Additionally, continuous fan operation helps to improve air filtration by constantly circulating air through the furnace filter, which can lead to better indoor air quality by removing dust, allergens, and other particles. Running the fan constantly can also help to reduce humidity levels in the home during the cooling season by circulating air over the evaporator coil of the air conditioning system. You will need to be mindful of your air filter if you decide to run the fan continuously. It is likely to get dirtier faster and may need to be changed more frequently than during operation in the “Auto” mode. Some homeowners may not want to do this in the deepest part of winter as it may make the house feel drafty. Overall, maintaining a constant airflow with the furnace fan can contribute to enhanced comfort, better air quality, and improved energy efficiency.