The part(s) or condition(s) listed below for the symptom Furnace blower not running are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
Furnace Blower Not Running? Gas Furnace Troubleshooting
Furnace Blower Runs All The Time? Gas Furnace Troubleshooting
Furnace Noisy Or Loud? Gas Furnace Troubleshooting
Furnace Starts Then Stops? Gas Furnace Troubleshooting
Furnace Not Heating? Gas Furnace Troubleshooting
Replace Furnace Filters - Tech Tips from Repair ClinicThe blower motor blows air through the return vent, past the heat exchanger, and into the home’s venting. First, make sure that power is getting to the motor. If power is getting to the blower motor, but the motor does not run, the motor may be burned out. If the blower motor is burned out, replace it. If the blower motor hums, check the blower fan to ensure that it spins freely. If the blower fan is unobstructed but does not spin freely, replace the blower motor.
If the capacitor is defective, the fan motor might be noisy, overheat, or not run at all. To determine if the capacitor has failed, inspect the capacitor. If the capacitor is bulging or leaking, replace it. The capacitor can also be checked with a meter.
Check to see if the furnace blower comes on when you jump the control board contacts for the red (“R”) and green (“G”) wire terminals. If it does, then it's likely the wall thermostat is defective and unable to alert the furnace control board to turn on the blower. You will need to replace the wall thermostat to regain control of the blower.
Check to see if the furnace blower comes on when you jump the control board contacts for the red (“R”) and green (“G”) wire terminals. If it does, then it's likely the WiFi thermostat is defective and unable to alert the furnace control board to turn on the blower. You will need to replace the WiFi thermostat to regain control of the blower.
The control board regulates the power supply to all of the components of the furnace. If the control board is defective, it might not send voltage to the blower motor.
The motor control board helps to maintain the desired motor speed of the blower. When the motor control board fails, the blower motor may not run at the correct speed or it may not run at all.
Check the blower wheel to ensure that it spins freely. If the wheel is obstructed, that will prevent the blower from running. A damaged blower wheel and housing should be replaced. If the blower wheel and housing are in good condition and unobstructed, but the blower wheel does not spin freely, the the blower motor has likely seized and will need to be replaced.
Check the blower wheel to ensure that it spins freely. If the wheel is obstructed, that will prevent the blower from running. A damaged blower wheel and housing should be replaced. If the blower wheel and housing are in good condition and unobstructed, but the blower wheel does not spin freely, the the blower motor has likely seized and will need to be replaced.
If the run capacitor is defective, the fan motor might be noisy, overheat, or not run at all. To determine if the run capacitor has failed, inspect the capacitor. If the capacitor is bulging or leaking, replace it. The capacitor can also be checked with a multimeter.
A wire harness, a group of wires with the required connectors and plugs, is used to control and monitor various furnace components. If a wire harness is damaged, one or more of the components may not run or may only run intermittently. A damaged wire harness will need to be replaced.
Check to ensure that power is getting to the furnace. If the furnace is not getting power, check the furnace circuit breaker or fuse.
