So, your furnace blower won’t turn on. As far as furnace failures go, this issue has the potential to be solved easily. With any luck, you may be able to pull off a successful repair all on your own. To help you restore the functionality of your system, we have compiled a list of troubleshooting methods that can be utilized to fix your furnace blower.

Inspect the Wires in Your Furnace
Make sure that the power cord hasn’t melted or a fuse hasn’t been blown. If your cables are looking fine, try unplugging the fan for a few minutes and then plugging it back in again. Sometimes, this process can reset the motor and solve your furnace problems.
If unplugging and plugging your fan back in again doesn’t work, check the fuse box. A surge in electricity may have overloaded your system, and the breaker has popped. Check your fuse box for popped breakers. If you find one, switch it back on.

Make Sure Your Thermostat Is Set and Working Correctly
If your blower fan has power, then the next step is to check the thermostat on your furnace. Most thermostats will be set to “auto” automatically when they come from the factory. However, sometimes your thermostat can malfunction, get old, or be set incorrectly, and you’ll need to implement a manual override.
Most thermostats will have three settings: “on,” “auto,” and “off.” For our purposes, try switching the thermostat to “on.” This adjustment will lock the fan into an always-on state. While this isn’t ideal in terms of power consumption, it will alleviate your furnace fan problems until a professional can get out to you and complete a full inspection and repair. If you switch the thermostat control to “on” and nothing happens, then try replacing the batteries in your thermostat or setting the temperature controls to 3-5 degrees above the temperature in the room. If none of these work, then you should call a furnace repair expert ASAP.

Check the Filters and the Vents
Blower motors are designed to circulate air, so they won’t work if there’s no air to move. You should always check the filters and vents surrounding the blower to make sure that the blower isn’t having a hard time working. Look into your air filter’s housing and check the markings on your filter. If your furnace blower won’t turn on, check to confirm the arrows on the air filter are pointing in the correct direction. When the arrows are pointing in the wrong direction, change the orientation of the filter. Next, check the vents around the blower.
Are the vents closed or clogged? Your blower might also be too dirty to work. If your blower looks dusty, spray away the dust with compressed air or wipe it away with a rag.

Check Your Furnace Blower’s Drive Belt
To figure out if the blower motor belt is damaged, turn off the furnace at the circuit breaker panel in your home. Next, head back to the furnace and inspect the belt that runs the blower. When the fan in a furnace is not working, this is an indicator of a worn down or cracked belt that needs to be replaced.

Is Your Blower Motor Humming?
If your blower motor is humming and lights turn on, but nothing is happening, your furnace issues probably stem from a bad capacitor. Blower motors use a lot of power. They’re heavy pieces of tech, after all. So, even if your furnace hooks up to a 240-volt outlet, it will still need a capacitor to store and discharge the 400+ volts it needs to run. If your furnace blower motor won’t turn on, the source of the issue may be a damaged capacitor. Once a load becomes too large, a capacitor can break and negatively impact the performance of your furnace.
Sometimes, that load becomes too much, and your capacitor will fry itself. You’ll know that your capacitor is bad when the hum you hear isn’t clicking or whining. A bad capacitor will always sound more like a buzz than anything else. We wouldn’t recommend doing this kind of repair yourself because of the high voltages involved.

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