Floor fan just hums

Usually a bad start capacitor on the fan motor. It jump starts the motor

usually a "humming motor" indicates either a bad capacitor or a defective motor. With the power off try to spin the blower wheel...it should spin freely. If it is tight or wont spin and there are no obstructions stopping it (like an air filter sucked into blower or other debris) then the motor most likely is seized. If the blower wheel spins free then you may have a bad capacitor. Keep in mind, just because the blower spins easy doesn't mean the motor is good. I have had motors that are defective that dont seize up but most of the time the blower wheel will not spin free if the motor fails.

If motor hums and does not spin, then motor has gone bad.
As motors get older, the motor begin to slow down.
Motors are designed to pull-in cool air across spinning coils inside the rotor.
Once the motor slows down, the motor no longer gets cool air, so it gets hotter, and then overheats, and then rotor no longer spins.
In years past, motors were taken to local electric shop for rewinding Then the motor went back into service.
Today, the motor is thrown in the landfill unless recycled at local scrap metal dealer.
It's a waste that we no longer have small repai9r shops to fix consumer goods like fans, and instead the economy causes us to import another motor because it's cheaper.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Please check the belt connecting the motor and drum. It could be loose or worn out. Also clean the belt with water. Check the couplings and ensure that they are not loose or worn out.

Hi,
Replace the fan motor capacitor... if that does not correct the problem, then replace the fan motor...

heatman101

You may need a new start capacitor or fan motor.I would have the capacitor checked by a electrician and changed if needed. Good luck and thank you.

Yes Dan the hum means power is going to the fan motor but the shaft is seized. If the photo on this site depicts your rangehood you may be able to fix it. Turn the power to the unit off. Remove the upper cowling. You should be able to see the fan. Sometimes it only takes a spin of the fan and a bit of spray on lubricant on the shaft to free it up. If it spins freely then turn power on and give it a try. Some fans will be seized tight and no matter what you do they won't spin. This means it's time to get a new fan motor.
Good luck.

Remove the top cover, plu it back in and see if the hum goes away, if it
doesn`t look to see if the fan is stuck, if it is unplug and try to spin it
by hand, if it wont spin replace the fan motor

If you are talking about the fan on the outdoor unit, let's try some things.
Kill power to the outdoor unit. Use breaker or disconnect. Now see if the fan will spin with no power going to the unit. If not, bad bearings. Fan D.O.A. If it does spin, good.
Now restore power and turn unit on. If fan runs now, it has a defective or damaged winding. Needs replacing. If it does not start running, most likely the capacitor is D.O.A. or the fan is "Electrically" locked up. Again, fan D.O.A.
If you do replace the fan motor, be sure to always replace the capacitor. It's usually only a few buck more.
Also, be extremely careful when trying to spin that fan. It may take off and take a finger with it. NEVER try to spin the fan with power going to it.
This is no joke, it's dangerous if you don't know what your doing.
It may well be worth having a tech check things out for you.
In any case, good luck and again, be extra careful. Never do this type of work alone, in case something happens unexpectedly.
And as a side note, you may find it next to impossible to find anyone to sell you the motor. Most all HVAC parts houses are wholesale only and will not sell to the general public just to HVAC companys. That's because they are trained to do this stuff with out injury.
Think it over and good luck.

Try taking it apart again and try to turn the motor by hand. It should spin freely. If it does you've probably got a bad motor. If it is stiff or doesn't turn at all, then you might have missed something putting it back together. I wouldn't think you can overtighten the blower, it is probably something else, and with it apart it should be easy to see.