I’m not sure about the protocol of running the fan on my heating and air conditioning system. I don’t want to overwork the fan and have it die on me. I also don’t want to not use the fan and have the system overwork. Since I was unsure of what I should do, I decided to call the HVAC company. I didn’t even realize I had a choice of turning the fan off. I just thought it was always on. When I was playing with the thermostat, I got into a fan setting. It had the choice of high, low, and off. This had me intrigued, but wondering if I was using it wrongly. The HVAC company had a website and I was able to glean a lot of information from there. According to the website, the life of the fan can be extended if I don’t turn it off and on as often. During the winter, the fan should always be on to eliminate any dead spot in the house, that doesn’t have good ventilation. The fan will also help to circulate the dust and keep the air cleaner, because it is being circulated into the air filter. During the summer, the fan can cause the cooler air to become trapped in small corners of the attic, and it is unable to come out because of the fan. I find it very confusing, because different websites have differing opinions. I may just leave the fan running all of the time. It hasn’t harmed my HVAC system, yet, and I don’t think it will.