Check to make sure your furnace has power. The blower could be failing due to a blown fuse in the house/circuit breaker, or the power source being turned off.
Change the setting of your home furnace. If you find that the blower is constantly running, it may be set to the "Fan" option. Fix this problem by changing the setting to "Auto." You may also find a fan control panel that allows you to set the number of hours each day that you want the fan to operate.
Reset your blower motor. In some cases, the home furnace's blower may have become overheated. Find the reset switch, and reset it to see if this resolves the problem.
Look at the belt of the blower motor. If the belt has broken, you will need to order a replacement motor belt. Also, look to make sure the belt has not slipped off the track.
Run a systematic check of the different switches. If your blower is not working, it could be a faulty switch causing the problem. A burned out or cracked blower wire could also be the cause of an inoperable home furnace.
Examine the duct work. If you don't feel hot air coming through the vents of the home, it could be an issue with the ducts, and not the actual blower. Check for any cracks or leaks in the ducts leading from the furnace into the home.