The red button blinks five times, but there is no flame when the motor is running. How do I go about fixing the problem? It pumps air, but its cold air

It is running in safe mode. Look at the code on the inside of the air handler door. We have no idea as to the make or model of your furnace. Typical issues include bad surface ignitor, dirty or bad flame sensor, plugged or bad pressure switch but could be others.