The fan on my furnace keeps running. Thermostat is set to auto. What should I do?

Question

I have an American Standard Freedom 90 Single Stage furnace. The AC is off and the fan is set to auto. However, the fan has been blowing for the last 24 hours. We've been in this house for 4 months and I don't recall this happening before. Anybody know why the fan is running and/or what I can do to make it stop?

Answer 1

There is a main timing board inside your furnace that controls fan on and off function, and speed. I would guess this has a bad relay inside that cannot be repaired without replacing the board. Sorry.

Answer 2

check the little three or four amp fuse in the furnace if its blown you have a low voltage short most likely contactor a furnace will blow all the time when that happens i do this for a living not guessing

Answer 3

Check the T stat and see if there is a auto/ run for the fan, most of the time it's cause the switch is on run and not on auto, flip the switch and see if that works. If it still doesn't shut the fan off you may need a new T stat, They have programable ones at Lowes or Home Depot should take about 15 minutes to replace it. also these will save you money as they can be programed to shut down when no one is home.

www.frankawitz.net

Answer 4

i agree with frank, you could also have the fan controller in the furnace malfunctioning. have this checed soon, you will wear out the bearings in the cage.

Answer 5

mine has two switches, on the left cool ,off ,heat on the right fan, auto,. ok if you want to heat or cool your house the right switch to auto and the left set to cool or heat.  to run the fan continously select off on the left and fan on the right.