I have an exhaust fan in my attic which is connected to a thermostat. Now it’s not working even if I set the thermostat to 65F. Any idea what is the reason. Is it thermostat wrong or fan? How could I test it?

Thanks

Shut off the power and remove the thermo from the wiring, wire it direct. Turn the power back on. Likely the thermo is bad. Check the line voltage too while you are at it, do that first to make sure you have juice.

Does the fan spin freely?

How's it going Ballenger?