Question

Why is my furnace blower motor humming before it starts up?

It just started happening today, whenever my furnace blower motor starts up when the air conditioner kicks on the furnace blower motor hums for around 4 to 5 seconds before it starts up?

The blower motor runs fine after it starts but hums for around 5 seconds before it actually starts up?

It acts like it's having a hard time spinning before it starts?

Answer 1

If your blower motor starts and runs fine after it hums for awhile that indicates a problem with the run capacitor.

I would change out the run capacitor and see if that fixes it. If you're uncomfortable with electricity or don't know how to replace the capacitor then have a furnace repair company replace it for you.

They can also fully test out and find the actual problem.

It could also mean that the blower motor is starting to go bad and may eventually seize up but for me when my furnace blower motor was humming it started working fine again after I changed the run capacitor.

The capacitor helps an electric motor start and if it's not working properly then the motor won't start at all or have a hard time starting.