Furnace Fan Not Working? Learn to Troubleshoot a Broken Furnace Blower

Updated October 16th, 2024

During the wintertime in Arizona, our service technicians often get calls from frustrated homeowners who have recently discovered that their furnace blower is not working. While we’re always happy to help these homeowners, the problem is often something that they can easily fix themselves. So, in an effort to save you the time and expense of a service call to your local HVAC contractor, we’re providing you with some basic furnace blower troubleshooting tips.

What to Check When Your Furnace Fan Won’t Turn On

Start simple and work your way up to the real challenges. Take these three steps as soon as you realize that your furnace isn’t working:

1. Check to see if the furnace circuit breaker has tripped. If it has, reset and allow time for a normal heating cycle.
2. Check to see if the thermostat is set appropriately. If set too low, you may be cold but your furnace thinks everyone is cozy at 50 degrees.
3. Always check the furnace filter. It should be cleaned or replaced monthly during the heating season. A clogged filter can drop airflow so much that your home’s ductwork shakes or your furnace overheats without sending the heat into your home.

Is the Air Cold or Warm?

If after trying those three steps you still are not warm, you need to feel the difference between cool airflow and no airflow. A furnace blower motor that stops pushing warm air out is not the same as a blower that is forcing only cold air into your home.

If you have cool air but a steady airflow, your blower motor is working but your heat exchanger or burner is not. Check the furnace flame for a completely blue color. Any yellow, red, or orange indicates dust and dirt buildup on the burner. Inspect the heat exchanger for cracks, which can cause a safety hazard.

Finally, Test the Blower Fan

Furnace Fan Still Not Turning On? Get Help from a Professional

You tried all these possible solutions and still have no air blowing? Now put your furnace’s blower fan to the test. Start by turning the furnace off, turn your thermostat to “fan only,” and wait a few minutes. If you see or hear the fan turn on, your blower motor is not the culprit. If the fan does not start, you have a wiring issue (circuit breaker trips) or motor problem (circuit breaker does not trip). While your thermostat may be at fault, only an HVAC technician can diagnose and remedy the issue correctly. Time to call in the experts!

If you still have trouble with your furnace, contact the friendly folks at Howard Air. We have experience in fixing a homeowner’s “fixes” that do not quite hit the mark. We can get your furnace blower motor working again safely, quickly, and reliably.

See also: Best residential furnace to buy