Puzzled why the furnace fan will run with the thermostat set lower than the house temp. We don't have an air-to-air exchanger and this seems like new behavior.
Does your tstat have a intermittent fan setting (sometimes called CIRC)? I use that setting during the spring/summer/fall to help the temp stay even throughout the house. It runs the fan 20 mins of every hour.
Well, I feel stupid - there is a CIRC setting that I never noticed before. Not sure how it got set to it, but that is what the mystery was. Thanks for the responses.