Why my blower doesn't stop

Check your thermostat settings... most have a switch for the blower to run constantly or to be automatic...

If the fan is controlled by an old style fan/limit switch it may be sticking.

If it does it in cycles check your filters for the limit switch (if thers no button it will auto reset and be a headache ) on most newer units the fan running and not firing is a fault indicator i.e.. . limit switch (push buttons between the LOW voltage wires ) pressure switch ( vent system ).. if you have a blinking light on the circuit board count the flashes and it will let you know which one it is.. Ive been hvac tech for 23 years.. number 1 cause or faults is dirty filters and will cause A lot of other problems..