Were at a point in the year we'd like to use "just" the fan to move air around the house. Problem is that when I put the T-stat on "fan" the blower does not come on. AC and Heat modes work perfectly. I put in a new T-Stat and main board last season and it worked fine until I went to use it the other day. What might be the problem?

Tim

Hey Tim , what's the make and model numbers of the stat and furnace?